Le volcanisme basaltique post-collisionnel d'

Keywords: Etude chronologique, magmatologique et géochimique Turquie, Anatolie Centrale, post-collisionnel, Quaternaire, basaltes, âge K-Ar, minéralogie, pétrologie, géochimie Turkey, Central Anatolia, post-collisional, Quaternary, basalts, K-Ar age, mineralogy, petrology, geochemistry

Evolution spatio-temporelle Résumé Cette thèse est consacrée à la caractérisation pétrologique et géochimique des basaltes quaternaires post-collisionnels d'Anatolie centrale (strato-volcans Erciyes et Hasandağ et volcanisme dispersé d'Obruk-Zengen et de Karapınar), en se focalisant sur l'évolution spatio-temporelle de ce magmatisme de la Cappadoce (Turquie). Par la géochronologie K-Ar, la coexistence de basaltes alcalins et calco-alcalins a été démontrée, parfois dans un même lieu et à la même époque. Par ailleurs, nos résultats montrent aussi que ces basaltes peuvent être très jeunes (quelques milliers d'années seulement). La minéralogie des basaltes quaternaires de la Cappadoce est la suivante : plagioclase, olivine, clinopyroxène, orthopyroxène et oxydes (magnétite, ilménite). Pourtant, seuls les basaltes de l'Erciyes contiennent de l'orthopyroxène, alors que ceux du Hasandağ et du volcanisme dispersé d'Obruk-Zengen et de Karapınar en sont dépourvus. Les phénocristaux de plagioclases présentent souvent des figures de déséquilibre, attribuées au processus de mélange magmatique : zonages complexes (normaux, inverses, oscillatoires), richesse en inclusions vitreuses, figures de résorption. Toutefois, la minéralogie observée est compatible avec un processus de cristallisation fractionnée dominant. Les géobaromètres utilisés montrent que l'origine des magmas de l'Erciyes est plus superficielle que celle des autres sites. Les résultats en géochimie confirment la dualité minéralogique observée entre l'Erciyes et les autres secteurs, ainsi que les caractères alcalins (néphéline normative) et calcoalcalins de basaltes parfois contemporains. Tous les basaltes étudiés sont enrichis en LREE et LILE. Les données isotopiques (Sr, Nd, Pb, O) montrent l'importance de la source lithosphérique enrichie. L'ensemble des données géochimiques montre aussi la signature d'autres sources et processus comme la contamination par la croûte continentale et l'héritage d'une ancienne subduction.

The purpose of the thesis is to present new geochronological, mineralogical and geochemical (major, trace and isotope elements) data on the Quaternary post collisional basaltic volcanism of Central Anatolia, to emphasize possible temporal and spatial evolution, and to evaluate the lithosphere-asthenosphere interactions.

Several studies have been performed about Mio-Pliocene acidic volcanism which is located in the Cappadocia region and cover large areas, and Quaternary

Hasandağ and Erciyes stratovolcanoes [START_REF] Ayrancı | Zur Petrologie und Geologie des Erciyes Vulkangebietes bei Kayseri Zentral Anatolien/Turkei[END_REF][START_REF] Keller | Quaternary Maar Volcanism near Karapınar in Central Anatolia[END_REF][START_REF] Batum | Nevsehir guneybatisindaki Göllüdag ve Acıgöl yöresi volkanitlerinin jeolojisi ve petrografisi (Geology and petrography of volcanics in Golludag and Acigol region to the SW of Nevsehir)[END_REF][START_REF] Ercan | Hasandağı-Karacadağ Orta Anadolu dolaylarındaki Senozoyik yaşlı volkanizmanin kökeni ve evrimi[END_REF]; [START_REF] Aydar | Etude Volcano-Structurale et Magmatologique du Strato-Volcan Hasan Dagı (Anatolie Central-Turquie)[END_REF][START_REF] Le Pennec | Neogene ignimbrites of the Nevşehir plateau, Central Turkey[END_REF][START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF][START_REF] Şen | Erciyes stratovolkanın'nın (Orta Anadolu) volkanolojik ve petrolojik gelişiminin incelenmesi[END_REF][START_REF] Temel | Kapadokya Eksplozif Volkanizmasının Petrolojik ve Jeokimyasal Özellikleri[END_REF][START_REF] Temel | Ignimbrites of Cappadocia: Petrology and Geochemistry[END_REF][START_REF] Deniel | The Hasan Dagı stratovolcano (Central Anatolia, Turkey): evolution from calc-alkaline to alkaline magmatism in a collision zone[END_REF][START_REF] Kürkçüoğlu | Erciyes stratovolkanı'nın Jeokimyasal Evrimi, Doktora Tezi[END_REF][START_REF] Alıcı Şen | Anadoluda'ki Kuvaterner Yaşlı Bazaltik Vokaniklerin Kökeni[END_REF][START_REF] Le Pennec | Stratigraphy and age of the Cappadocia ignimbrites, Turkey: reconciling field constraints with paleontologic, radiochronologic, geochemical and paleomagnetic data[END_REF]. Significant contributions have been proposed in the literature about the geochronology, stratigraphy, petrology and geochemistry, but there are no adequate data on the basaltic volcanism spreading over large areas in Cappadocia.

The purpose of sampling was to collect Quaternary basaltic volcanics that represents the post-collisional characteristics of the Central Anatolia. On this basis, total 63 samples were collected from the study area. Fresh and unaltered 43 samples have been selected for thin section. These 43 thin sections were examined under the microscope and 34 samples among them were selected for geochemical studies (major and trace element analyses).

According to major and trace element analyses, LOI contents, hand specimen and thin section observations of the samples and the previous workers studies, [START_REF]Temporal evolution diagram shows that 206 Pb/ 204 Pb ratio of HS regularly increases from the oldest sample to the youngest sample and by the increase of SiO 2 values (Figure 5.32) as well as in Sr-Nd vs Age diagrams (Figure 5.26). In OZ, except the samples of HA14 and HA15 (Figure 5.31), 206 Pb/ 204 Pb isotope ratio increases from oldest to youngest samples as seen in Nd-isotope vs. Age diagram (Figure 5.26). K, presents not a significant correlation in Pb-isotope vs. Age and SiO 2 diagrams however slightly positive correlation can[END_REF] unaltered samples were decided to the analyses of mineral chemistry and for geochronological studies. In the light of preliminary data of mineral chemistry and petrography; K-Ar dating, radiogenic 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, 208 Pb/ 204 Pb, 87 Sr/ 86 Sr, 143 Nd/ 144 Nd and stable isotope (oxygen) analyses were conducted. All these analyses were financed by TUBITAK (The Scientific and Technological Research Council of Turkey; Research Project 109Y064).

Studied Areas

The studied areas are located in 1/100 000 scaled Kayseri L-34, K-34, L-35, K-35, Aksaray L-32 and Karaman M-32, M-31 sheets and are given in

Previous Studies in Cappadocia

Central Anatolia (Cappadocia) is a region which is located between the Africa-Arabic and the Eurasian convergent plates. Widespread volcanism that developed after continental collision between the Afro-Arabian and Eurasian plates that began during the early to middle Miocene [START_REF] Şengör | Türkiyenin Neotektoniğinin Esasları[END_REF][START_REF] Şengör | Tethyan evolution of Turkey: a plate tectonic approach[END_REF][START_REF] Dewey | Shortening of continental lithosphere: The neotectonics of Eastern Anatolia, a young collision zone. Collisionc Tectonics[END_REF]. The Cappadocian volcanism cropped out as stratovolcanoes and basaltic and rhyolitic monogenic vents in Miocene-Quaternary times [START_REF] Aydar | Kapadokya bölgesinin Kuvaterner yaşlı volkanizmasının yapısal ve petrolojik incelemesi[END_REF].

The asidic ignimbritic volcanism in Cappodocia is very spectacular and bulky in Mio-Pliocene. The ignimbrites covered area of approximately 40.000 km 2 and 1000 km 3 in volume [START_REF] Temel | Kapadokya Eksplozif Volkanizmasının Petrolojik ve Jeokimyasal Özellikleri[END_REF][START_REF] Le Pennec | Neogene ignimbrites of the Nevşehir plateau, Central Turkey[END_REF][START_REF] Temel | Ignimbrites of Cappadocia: Petrology and Geochemistry[END_REF].

Pasquare (1968) mapped ignimbrite units in Central Anatolia and exhibited their stratigraphy. Le [START_REF] Le Pennec | Neogene ignimbrites of the Nevşehir plateau, Central Turkey[END_REF] reviewed the stratigraphical sequences of ignimbrites presented in previous studies (Pasquare, 1968;Pasquare et al., 1988;[START_REF] Schumacher | Depositional characteristics of ignimbrites in Cappadocia, Central Anatolia, Turkey[END_REF] and estimated the volumes of the different ignimbritic units. Some other previous workers performed K/Ar dating on ignimbrites in the region. [START_REF] Innocenti | The Neogene calc-alcaline volcanic of Central Anatolia: Geochronological data on Kayseri-Niğde area[END_REF] presented the age of the Valibaba ignimbrite is 2.7-3.0 ± 0.1 Ma, Şen et al. (2003) also dated the Valibaba ignimbrite at 2.8 Ma and Ayrancı (1969) dated ignimbrite located around Erkilet, at 8.53 ± 0.47 Ma.

Erciyes and Hasandağ stratovolcanoes, Obruk-Zengen and Karapınar dispersed [START_REF] Keller | Quaternary Maar Volcanism near Karapınar in Central Anatolia[END_REF] volcanisms are significant part of Quaternary basaltic volcanism in Central Anatolia. Moreover, the basaltic volcanism accompanied with the large rhyolitic ignimbritic volcanism for more than 10 Ma helps us to understand the nature and the spatio-temporal processes of the mantellic sources of this postcollisional volcanism. The first detailed stratigraphic studies for the Erciyes and Hasandağ stratovolcanoes were made by Şen (1997) and [START_REF] Aydar | Etude Volcano-Structurale et Magmatologique du Strato-Volcan Hasan Dagı (Anatolie Central-Turquie)[END_REF], respectively. [START_REF] Ercan | Hasandağı-Karacadağ Orta Anadolu dolaylarındaki Senozoyik yaşlı volkanizmanin kökeni ve evrimi[END_REF] mapped different rock types around Hasandağ stratovolcano. The volcanological and petrological characteristics of Karataş basalts (northwest of Hasandağ stratovolcano) presented by [START_REF] Aydar | Karataş volkanitlerinin (Orta Anadolu) volkanolojik ve petrolojik özellikleri[END_REF].

Besides, Şen et al. (2002; 2003) studied the products related to the Dikkartın Mountain and Koçdağ from Erciyes.

Geochemical, isotopic and radiometric data from various types of volcanic rocks on Erciyes and Hasandağ stratovolcano, Karapınar and monogenic centers presented by many workers; Pasquare (1968), [START_REF] Innocenti | The Neogene calc-alcaline volcanic of Central Anatolia: Geochronological data on Kayseri-Niğde area[END_REF], [START_REF] Ercan | Hasandağı-Karacadağ Orta Anadolu dolaylarındaki Senozoyik yaşlı volkanizmanin kökeni ve evrimi[END_REF][START_REF] Olanca | Géochimie des laves quaternaires de Cappadoce (Turquie): les appareils monogéniques, Thése 3 eme cycle[END_REF], [START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF], [START_REF] Aydar | Le volcanism quaternaire d'Anatolie central (Turquie): Association de magmatisme calco-alcalin et alcalin en domaine de convergence[END_REF], [START_REF] Aydar | The geology of Mount Hasan stratovolcano, Central Anatolia, Turkey[END_REF], [START_REF] Kürkçüoğlu | Geochemical approach to magmatic evolution of Mt.Erciyes stratovolcano Central Anatolia, Turkey[END_REF]2001;2004;2010), Şen et al (2003), [START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF], [START_REF] Deniel | The Hasan Dagı stratovolcano (Central Anatolia, Turkey): evolution from calc-alkaline to alkaline magmatism in a collision zone[END_REF], [START_REF] Doğan | Climate-controlled river terrace formation in the Kızılırmak Valley, Cappadocia section, Turkey: Inferred from Ar-Ar dating of Quaternary basalts and terraces stratigraphy[END_REF], Gençalioğlu-Kuşcu (2010) and [START_REF] Gençalioğlu-Kuşçu | Review of post-collisional volcanism in the Central Anatolian Volcanic Province (Turkey), with special reference to the Tepekoy Volcanic Complex[END_REF]. These previous workers discussed the geodynamical processes related to the formation of the contemporaneous Quaternary alkaline and calc-alkaline magmatism in Central Anatolia. According to Pasquare (1968) and [START_REF] Innocenti | The Neogene calc-alcaline volcanic of Central Anatolia: Geochronological data on Kayseri-Niğde area[END_REF], volcanic activity was related to subduction event. On the other hand, [START_REF] Aydar | Le volcanism quaternaire d'Anatolie central (Turquie): Association de magmatisme calco-alcalin et alcalin en domaine de convergence[END_REF], [START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF] and [START_REF] Kürkçüoğlu | Geochemical approach to magmatic evolution of Mt.Erciyes stratovolcano Central Anatolia, Turkey[END_REF]2001;2004;2010) stated that this magmatism was related to intracontinental activity. [START_REF] Deniel | The Hasan Dagı stratovolcano (Central Anatolia, Turkey): evolution from calc-alkaline to alkaline magmatism in a collision zone[END_REF] stated that the strong calc-alkaline character of Hasandağ lavas, in the absence of contemporaneous subduction, must be related to the heritage of the early subduction. İlbeyli (2004) also asserted that alkaline and calc-alkaline magmatisms indicated that mantle source before collision was heterogeneous under the Central Anatolian area and the magmas derived from an enriched source, with traces of a previous subduction. Alıcı Şen et al. (2004) revealed that the Central Anatolian volcanism derived from a lithospheric mantle source in which the effects of an ancient subduction occurred. [START_REF] Güçtekin | Geochemical Characteristics of Mafic and Intermediate Volcanic Rocks from the Hasandağ and Erciyes Volcanoes (Central Anatolia, Turkey)[END_REF] also support this and they claimed that Central Anatolia volcanics were formed by the partial melting of a metasomatized lithospheric mantle. Doğan et al. (2013) and Gençalioğlu-Kuşçu (2010) added, Erciyes mafic lavas and monogenic basalts of Cora Maar (Northwest of Erciyes)

formed by shallow melting of a garnet-free lithospheric mantle, respectively. On the other hand, [START_REF] Kürkçüoğlu | Interaction of asthenospheric and lithospheric mantle: the genesis of Calcalkaline Volcanism at Erciyes Volcano, Central Anatolia, Turkey[END_REF] claimed that calc-alkaline magmas are related to the partial melting of depleted and enriched asthenospheric sources.

They stated that the partial melting was followed by AFC process and the resulting magmas did not derive directly from a melting of subducting slice but from a tholeiitic component.

According to mineralogical and petrological data [START_REF] Aydar | The geology of Mount Hasan stratovolcano, Central Anatolia, Turkey[END_REF] both magma mixing and fractional crystallization are the main petrological processes leading to andesitic and dacitic rocks at Hasandağ stratovolcano. Other study in Central Anatolia [START_REF] Siebel | Acigöl rhyolite field, central Anatolia (part II): geochemical and isotopic (Sr-Nd-Pb, d18O) constraints on volcanism involving two high-silica rhyolite suites[END_REF] is the rhyolitic Acıgöl area and they claimed that crustal melting, fractional crystallization at high rate and finally mixing with basaltic/andesitic magmas occurred in the genesis of the rhyolites. However, [START_REF] Dogan | Petrogenesis of mafic-silicic lavas at Mt. Erciyes, central Anatolia, Turkey[END_REF] claimed that magma mixing process is the major process for the genseis of the Erciyes silicic lavas. [START_REF] Güçtekin | Geochemical Characteristics of Mafic and Intermediate Volcanic Rocks from the Hasandağ and Erciyes Volcanoes (Central Anatolia, Turkey)[END_REF] emphasized fractional crystallization is an effective processes not only for Hasandağ tholeiitic, alkaline and calc-alkaline rocks but also for Erciyes alkaline and calc-alkaline rocks. [START_REF] Aydar | Kapadokya bölgesinin Kuvaterner yaşlı volkanizmasının yapısal ve petrolojik incelemesi[END_REF] mentioned that fractional crystallization was the predominant process during the magma evolution of Erciyes and Hasandağ stratovolcanoes, but magma mixing was also effective. Moreover, they stated that when the crustal effect is not considered, the basalts exhibit the mineralogy and chemistry of intra-plate basalts [START_REF] Aydar | Karataş volkanitlerinin (Orta Anadolu) volkanolojik ve petrolojik özellikleri[END_REF]. Isobaric and isenthalpic magma mixture of basalt and rhyolite were the main process of the magmatic evolution at Hasandağ stratovolcano [START_REF] Doğan | An isobaric-isenthalpic magma mixing model for the Hasan Dagi volcano, Central Anatolia, Turkey[END_REF][START_REF] Üstünışık | The role of fractional crystallization, magma recharge, and magma mixing in the differentiation of the Small Hasandag volcano, Central Anatolia, Turkey[END_REF]. [START_REF] Toprak | Keçiboyduran-Melendiz fayı ve bölgesel anlamı (OrtaAnadolu)[END_REF] defined 2 different fault systems in Neogene-Quaternary Central Anatolian Volcanic Province. The first system covers Tuz gölü fault, which is a right lateral strike slip fault, and the Ecemiş Fault, which is a left lateral strike slip fault. Other faults run parallel to these 2 fault systems. They claimed that volcanic centers (as Hasandağ, Keçiboyduran and Melendiz stratovolcanoes) were in the juxtaposition of these two fault systems. Ecemiş Fault Zone had gained its main strike slip in pre-Lutetian times and had an offset of 80±10 km [START_REF] Yetiş | Ecemiş fay kuşağının jeo-tektonik evrimi[END_REF]. Extensional strike slip faults in Northern Ecemiş Fault Zone were synchronous (Early Messinien and Early Pleistocene)

with Erciyes Basin. That means that Ecemiş Fault Zone was kinematically associated with Erciyes Basin Jaffrey et al. (2004). [START_REF] Dirik | Neotectonic characteristics of Central Anatolia[END_REF] stated that the Tuz gölü and Sultansazlığı basins along with the Ecemiş Fault Zone is an active pull apart basin since the Early Quaternary. They emphasized that seismic activities, which occurred in recent times, indicate that Central Anatolia is tectonically active. Besides, Özsayın et al. (2013) emonstrated that the average vertical displacement rates are different at eastern and western flanks of Tuz Gölü Lake. According to their study NNW-SSE to NE-SW contraction ended by 6.81 ± 0.24 Ma and was followed by N-S to NE-SW extension during the Pliocene-Quaternary periods. According to [START_REF] Temel | Ignimbrites of Cappadocia: Petrology and Geochemistry[END_REF] from Miocene (11.2 Ma) to Quaternary times, decreasing 87 Sr/ 86 Sr ratio of ignimbritic rocks may be linked with the transition from collisional to extensional tectonics. In addition, the transition from calc-alkaline to alkaline compositions through time is related to the development of extensional tectonics in Central Anatolia in the Late Miocene [START_REF] Deniel | The Hasan Dagı stratovolcano (Central Anatolia, Turkey): evolution from calc-alkaline to alkaline magmatism in a collision zone[END_REF]. Based on DEM (Digital Elevation Modeling) and field data of [START_REF] Dhont | Emplacement of volcanic vents and geodynamics of Central Anatolia, Turkey[END_REF] also support this review.

Laboratory Studies and Analytical Methods

Mineralogy and Petrography

 Polarized microscope

Samples collected from the studied area were cut and left for drying. Later on these samples were carefully studied under the daylight and parts considered as altered were then rasped in cutting machine in "Magmas et Volcans" laboratory, Blaise Pascal University (Clermont-Ferrand/France). After this process, thin sections were prepared. Thin sections were polished at 3 different processes with 10 minute periods each in Mecatech 334 brand machine.

 Electron Probe Micro Analyses (EPMA)

In order to determine the chemical compositions of minerals, a Cameca SX-100 brand electron microscope was used at "Magmas et Volcans" laboratory, Blaise

Pascal University (Clermont-Ferrand/ France). Analyses were made at 15 kv, 10-12 nA and 10 s for phenocrysts, microphenocrysts and microlites, and at 15 kv, 4 nA and 5µm, 10 s for glass analyses. Na and K elements were analyzed first, in order to prevent to the migration of these mobile alkaline elements.

Geochemical Analyses

 Major and trace elements analytical methods

For the accuracy of the analyses, fresh and unaltered samples were selected.

Selected samples were cut and made into small chips in jaw crusher. Afterwards, small chips milled in agate mortar. The trace and rare earth element analyses have been made at the Center of Petrographic and Geochemical Research (Centre de Recherches Pétrographiques et Géochimiques) (Nancy/ France). Main element dissolutions were expressed in oxide %. Trace and rare earth element analyses were expressed in ppm (parts per million).

 ICP-AES (Inductively Coupled Plasma -Atomic Emission Spectrometry)

Major element (Si, Al, Fe, Mn, Mg, Ca, Na, K, P, and Ti) analyses have been performed at Service d'Analyse des Roches et des Minéraux, CRPG -CNRS (Nancy/France) using Jobin-Yvon JY 70. Powdered samples (200 mg) were molten by LiBO 2 (Lithium metaborate) and dissolved by HNO 3 . Prepared solutions were analyzed by the automatic procedure installed in the system. Detection limits and uncertainties at given intervals for major elements were given in Table1.1

(http://helium.crpg.cnrs-nancy.fr/SARM/pages/roches.html).

 Isotope analyses

Sr-Nd-Pb

During the selection of the sample for isotope analysis, hand specimen and thin section observations, major and trace element results, LOI contents and previous wrokers studies were taken into consideration. The Sr, Nd and Pb isotope analyses were performed by C.Deniel, both at UMR 6524 Clermont-Ferrand (Sr and Nd) and ENS Lyon (Pb).

Isotopic analyses for Sr and Nd were made using Thermo-Finnigan Triton (TI)

brand mass spectrometer at the "Magmas et Volcans" laboratory, Blaise Pascal University (Clermont-Ferrand/France).

Samples selected for isotope analyses were prepared in 4 different data sets and measurements have been completed at different periods. Selected samples were first crushing by jaw crusher at the laboratory "Magmas et Volcans", quartered then approximately 50 mg of it was separated (hand picked selection of unaltered chips). A part of 0.5 mg was selected from unaltered crushed small chips that have no sign of cutting or alteration. Then, 0.2 mg of the selected 0.5 mg grains were weighed then put into teflon beakers. These separated samples were first washed for 10 minutes by 2N HCl, then was cleaned by distilled water. Later, 1 ml HNO 3 +4 ml HF was added and placed on a hot plate at 90°C. During 2 days, three times a day (morning, noon and night) ultrasonic bath were applied then they were again put onto the hot plate. After dissolution process had been completed, Pb, Sr and Nd elements were separated by the method of ion exchange chromatography. Pb isotope analyses were carried out at Ecole Normale Supérieure de Lyon (France) using MC-ICP-MS (Multicollector mass spectrometer) (Nu instrument 041). In order to follow the mass fractionation in Pb isotope measurements Tl (thallium) spike has been added [START_REF] White | High-precision analysis of Pb isotope ratios by multi-collector ICP-MS[END_REF]. The Pb isotopic ratios were corrected for instrumental fractionation using average measured values of the NBS981 standard. Total blank levels were less than 50 pg.

O (Oxygen)

Based on the handspecimen, thin section, major and trace element results of the samples, low LOI contents and unaltered samples were selected for stable isotope analysis. 0.7 mg of powder samples, which milled in agate mortar were manupulated for oxygen isotope analyses.

Oxygen isotope analyses have been performed at the Stable Isotope Laboratory of Jean-Monnet University by Marie-Christine Gerbe, Laboratory of Lithospheric

Transfers (LTL) (Saint-Etienne, France).
The extraction of oxygen from the whole rocks and minerals is performed on a conventional extraction line type by reaction at high temperature with BrF 5 (Bromine pentafluoride) and oxygen is converted to CO 2 [START_REF] Clayton | The use of bromine pentaflouride in the extraction of oxygen from oxides and silicates for isotopic analysis[END_REF]. The performance of each analysis was calculated by systematically measuring the volume of CO 2 obtained during the conversion reaction. For oxygen isotope measurement of each series, MQ laboratory standard (Université de Capedown, South Africa, Murchinson Quartz) used regularly. MQ results calibrated according to the suggested international quartz standard NBS-28 10.1±0.2 [START_REF] Vennemann | The rate and temparature of reaction of ClF3 with silicate minerals, and their relevance to oxygen isotope analysis[END_REF]. The average of the repetitive measurements (N=16) of MQ value was determined as (10.01±0.10). This value is very close to the recommended value. The accuracy and preciseness of analyses were 0.3‰ (2 sigma) during the separation of oxygen from silicates in LTL.

Oxygen isotope analyses were performed on a micromass isoprime triple collector-dual inlet mass spectrometer. In order to correlate the oxygen gas of samples in measurements, the references NBS19 and CO8 carbonate gases were used. The measurement results were normalized as δ18O‰=(R sample/R standard-1)×10 3 , R=( 18 O/ 16 O) according to the Standard Mean Ocean Water (VSMOW) [START_REF] Coplen | The rate and temperature of reaction of ClF3 with silicate minerals, and their relevenace to oxygen isotope analysis[END_REF]. Duplicates were made for 12 whole rock samples to determine the average reproducibility of analyzes of our samples. It is ± 0.3 ‰ for whole rock (2 sigma).

K-Ar Dating Method

The selection of the samples for the analysis of K-Ar dating; major and trace elements results, LOI values, macroscopic (hand specimen)-microscopic (thin section) observations and the previous studies were taken into account.

The dating of selected samples has been performed in Laboratoire des Sciences du Climat et de l'Environnement by Hervé Guillou, Unité Mixte de Recherche CEA-CNRS (LSCE) in Gif-sur-Yvette, France.

Samples were crushed (nearly 500 g) and sieved to 0.25 -0.125 mm size fraction.

Approximately, 60 g of fractioned samples were washed in ultrasonic bath with

GENERAL GEOLOGY

General Setting of the Studied Areas in Cappadocia

The tectonic regime changed as a result of the collision of the Eurasian and Arabian plates in the Middle (Early) Miocene, marking the beginning of neotectonic times [START_REF] Şengör | Türkiyenin Neotektoniğinin Esasları[END_REF][START_REF] Şengör | Tethyan evolution of Turkey: a plate tectonic approach[END_REF]. Due to the effects of this collision in Eastern Anatolia, deformations started on the continental crust along the Bitlis Suture Belt. The shortening and thickening of the crust with time was not able to compensate for the deformations, and the Anatolian block started to move westward along the NAF (North Anatolian Fault) and EAF (East Anatolian Fault), which are strike-slip faults [START_REF] Mckenzie | Active tectonics of the Mediterranean Region[END_REF][START_REF] Şengör | Strike slip faulting and related basin formation in zones of tectonic escape: Turkey as a case study, Strike-slip Deformation, Basin Formation and Sedimantation[END_REF][START_REF] Dewey | Shortening of continental lithosphere: The neotectonics of Eastern Anatolia, a young collision zone. Collisionc Tectonics[END_REF]. Intraplate deformations developed in the Anatolian Block during this period as well as pull apart basins and thrust faults [START_REF] Şengör | Türkiyenin Neotektoniğinin Esasları[END_REF][START_REF] Dhont | Emplacement of volcanic vents and geodynamics of Central Anatolia, Turkey[END_REF][START_REF] Seyitoğlu | A Late Pliocene-Quternary pinched crustal wedge in NW Central Anatolia, Turkey: a neotectonic structure accommodating the internal deformation of the Anatolian plate[END_REF].

The Anatolian Plate was the scene of intense volcanic activity, mainly The first detailed stratigraphic studies for the Erciyes and Hasandağ stratovolcanoes were made by Şen (1997) and [START_REF] Aydar | Etude Volcano-Structurale et Magmatologique du Strato-Volcan Hasan Dagı (Anatolie Central-Turquie)[END_REF], respectively.

UTM coordinates of 29 samples, and of other samples belonging to the four regions for which the ages had been determined using K/Ar dating, are given in Basaltic bomb-Acıgöl maar

Overview on Post-Collisional Magmatism

Post-collisional magmatism is one of the common features of many orogens around the world [START_REF] Dewey | Extensional collapse of orogens[END_REF]. Post-collisional settings are identified as a "relaxation phase" after collision (Liégeois et al., 1998). According to Liégeois et al.

(1998), post-collisional geodynamic settings are not completely understood.

However, [START_REF] Wang | Geochemical constraints for the genesis of post-collisional magmatism and the geodynamic evolution of the northern Taiwan region[END_REF] state that, petrogenetic studies of post-collisional magmatism provide to understand the geodynamic processes such as; interruption of collision, beginning of extension and reveal changes in magma source regions associated with such processes.

One of the widespread characteristics of post-collisional magmatism is its subduction-related geochemical characteristics despite subduction processes having been terminated as a result of continental collision [START_REF] Wang | Geochemical constraints for the genesis of post-collisional magmatism and the geodynamic evolution of the northern Taiwan region[END_REF][START_REF] Seyitoğlu | Late Cnezoic volcanic evolution of the northeastern Aegean region[END_REF][START_REF] Seyitoğlu | The evolution from Miocene potassic to Quaternary sodic magmatism in western Turkey: Implications for enrichments processes in lithospheric mantle[END_REF]. In addition, the subduction-related signatures are attributed to metasomatism by slab-derived fluids of the mantle lithosphere prior to collision [START_REF] Pearce | Genesis of collision volcanism in Eastern Anatolia, Turkey[END_REF][START_REF] Turner | Some geodynamic and compositional constraints on "post orogenic" magmatism[END_REF][START_REF] Turner | Timing of Tibetan uplift constrained by analysis of volcanic rocks[END_REF][START_REF] Turner | Post-collision, Shoshonitic Volcanism on the Tibetan Plateu: Implications for Convective Thinning of the Lithosphere and the Source of Ocean Island Baslats[END_REF][START_REF] Platt | Covective removal of lithosphere beneath mountain belts: thermal and mechanical consequences[END_REF], Peccerillo,1999).

Post-collisional magmatism has been observed in Neogene-Quaternary times in Turkey, Italy, Spain and the North Africa [START_REF] Halloul | The post-collisional volcanism of northern Tunisia: petrology and evolution through time[END_REF]. The formation of the Neotethys Ocean which was opened in Triassic and started to close in Late Cretaceous has a great significance on the development of Anatolia in Turkey [START_REF] Şengör | Tethyan evolution of Turkey: a plate tectonic approach[END_REF]. The closure of Neotethys led to the collision and continued during Paleocene to Early Eocene times [START_REF] Şengör | Tethyan evolution of Turkey: a plate tectonic approach[END_REF][START_REF] Koçyiğit | Post-Collisional Tectonics of Eskişehir-Ankara-Çankırı segment of İzmir-Ankara-Erzincan Suture Zone: Ankara Orogenic Phase[END_REF]Koçyiğit et al., 2003). In Neogene-Quaternary times, the postcollisional volcanism occured in Central Anatolia Volcanic Province (CAVP), as mentioned above. Mostly this post-collisional volcanism is bimodal and characterized by calc-alkaline andesites-dacites, with subordinate tholeiitictransitional-mildly alkaline basaltic volcanism of the monogenetic cones (Kuşçu and Geneli, 2010). Another example for bimodal character of post-collisional volcanism is the Foça Volcanic Center (FVC) from Western Anatolia [START_REF] Altunkaynak | Causes and effects of geochemical variations in late Cenozoic volcanism of the Foça volcanic centre, NW Anatolia, Turkey, Special Issue: Eastern Mediterranean Geodynamics, Part II[END_REF]. In FVC the older units were identified high-K calc-alkaline basalt, andesite, trachyandesite, rhyolite, and associated pyroclastic rocks and the younger sequences include shoshonitic-alkaline basalt lavas and dikes, trachytes, phonolites, and phonolitic ignimbrites that formed strombolian cones.

According to El [START_REF] El Bakkali | Post-collision neogene volcanism of the Eastern Rif (Morocco): magmatic evolution through time[END_REF] and [START_REF] Maury | Post-collisional Neogene magmatism of the Mediterranean Maghreb margin: a consequence of slab breakoff[END_REF], there is a strong relationship between the tectonics and the timing of the magmatism. Besides, the major tectonic elements and some local faults are active in Neogene-Quaternary times in Central Anatolia and volcanism is related to an ancient subduction [START_REF] Deniel | The Hasan Dagı stratovolcano (Central Anatolia, Turkey): evolution from calc-alkaline to alkaline magmatism in a collision zone[END_REF][START_REF] Temel | Ignimbrites of Cappadocia: Petrology and Geochemistry[END_REF][START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF][START_REF] Kürkçüoğlu | Geochemistry and petrogenesis of basaltic rocks from the Develidag volcanic complex, Central Anatolia, Turkey[END_REF]. The study of [START_REF] Altunkaynak | Causes and effects of geochemical variations in late Cenozoic volcanism of the Foça volcanic centre, NW Anatolia, Turkey, Special Issue: Eastern Mediterranean Geodynamics, Part II[END_REF] proposes spatio-temporal evolution of volcanism in western Anatolia (FVC) during Miocene times. They stated that the changes in geochemical nature of the volcanism and tectonic regimes might have been caused by successive thermal relaxations associated with possible 'piecemeal' removal of the base of subcontinental lithospheric mantle beneath western Anatolia.

Accordingly, the purpose of the thesis is to emphasize possible temporal and spatial evolution of the Quaternary post collisional basaltic volcanism in Central Anatolia. [START_REF] Ayrancı | The magnificent volcano of Central Anatolia: Mt. Erciyes near Kayseri[END_REF].

The Basement Rocks of Cappadocia

Briefly Overview of the Major Element Analysis and the Classification of the Erciyes Stratovolcano and Southwestern Cappadocia Samples

In order to understand the revisions made on the stratigraphic sections (

The Erciyes Stratovolcano

The Quaternary Erciyes stratovolcano (3916 m), located 15 km south of Kayseri city, is the highest volcano of Central Anatolia and covers an area of 3300 km 2 . The Erciyes volcanic system consists of a large volcanic cone of various pyroclastics and lavas, with numerous monogenic vents (dome, cinder cone and maar). According to Şen (1997) The ultimate products of the Koçdağ stage consist of pyroclastics, mainly Plinian pumice fall-out and ignimbrites of the Valibaba sequence (Şen, 1997). The ages of the Valibaba ignimbrite are 2.7±0.1, 2.8±0.1 and 3.1±0.1 Ma, according to [START_REF] Innocenti | The Neogene calc-alcaline volcanic of Central Anatolia: Geochronological data on Kayseri-Niğde area[END_REF]. This ignimbritic sequence is related to the collapse of a caldera, and followed by sub-contemporaneous dacitic domes and intracaldera andesitic lavas, with a K/Ar age of 2.544±0.306 Ma [START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF]. So, the Koçdağ stage ends with the collapse of the caldera and then the beginning of the Erciyes s.s. stage started at the west of Koçdağ. [START_REF] Kürkçüoğlu | Erciyes stratovolkanı'nın Jeokimyasal Evrimi, Doktora Tezi[END_REF] stated that basalts were the first products of the Erciyes s.s.

stage. Besides, he indicated that he did not encounter the basaltic products at the western and southwestern parts of the Erciyes stratovolcano that mentioned from [START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF]. On the other hand, [START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF], emphasized that their sample ER24 (1.734±0.069 Ma), which is an alkaline basalt, was located on the southwestern of Erciyes stratovolcano (precise UTM coordinates were not indicated, only coordinates given as Şeyhşaban, Figure 2.2). In this study, our sample ER13 (1.695±0.037 Ma) is an alkaline, trachybasalt (Figure 2.6) from a basaltic lava flow at southeastern part of İncesu town (Figure 2.2). Although there are some differences between major elements of both samples, the ages of ER24 [START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF] and ER13 are at the same age interval and both located on the western flank of the Erciyes stratovolcano. This information indicates the presence of a basaltic lava flow across these areas.

This basaltic unit is overlain by the first generation of andesitic various products and after the first generation of dacitic domes and flows occurred. The K/Ar age of these dacites is 0.9±0.2 Ma [START_REF] Innocenti | The Neogene calc-alcaline volcanic of Central Anatolia: Geochronological data on Kayseri-Niğde area[END_REF]. Dacites are followed by basaltic andesite and blocky lavas at 0.53 ± 0.04 and 0.29 ± 0.04 Ma [START_REF] Ercan | Erciyes Dağı Orta Anadolu Pliyo-Kuvaterner volkanizmasina ilşkin yeni jeokimyasal, izotopik, radyometrik veriler ve jeotermal enerji açısından önemi[END_REF] and by calc-alkaline ER3 (0.352 ± 0.009 Ma) and ER10 (0.297±0. 015 Ma) basaltic-andesites, according to this study. These units are covered by the second generation of dacites dated at 0.3 ± 0.1 Ma [START_REF] Innocenti | The Neogene calc-alcaline volcanic of Central Anatolia: Geochronological data on Kayseri-Niğde area[END_REF], flowing towards the northwest. It is followed by the second basaltic generation, dated at 0.15 ± 0.07 Ma K/Ar by [START_REF] Ercan | Erciyes Dağı Orta Anadolu Pliyo-Kuvaterner volkanizmasina ilşkin yeni jeokimyasal, izotopik, radyometrik veriler ve jeotermal enerji açısından önemi[END_REF]. The calc-alkaline samples of this study ER20 (0.115 ± 0.007 Ma), ER30 (0.102±0.007 Ma) and ER1 (0.093±0.011 Ma) are at the same time interval (Figure 2.7). The occurrence of alkaline and calc-alkaline basalts at this stage of the Erciyes stratovolcano has been noted by [START_REF] Kürkçüoğlu | Erciyes stratovolkanı'nın Jeokimyasal Evrimi, Doktora Tezi[END_REF]. These basaltic lavas are overlain by the second generation of andesites dated at 0.171 ± 0.12 Ma K/Ar by [START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF] The volcanic activity, which became more explosive in character after the andesitic period, continued with dacitic and rhyodacitic extrusive, eruptions (Şen, 1997).

Volcanic activity continued in recent times as rhyodactic pumice flows, base surge and plinian fallouts spread over large areas around a dome. [START_REF] Ercan | Erciyes Dağı Orta Anadolu Pliyo-Kuvaterner volkanizmasina ilşkin yeni jeokimyasal, izotopik, radyometrik veriler ve jeotermal enerji açısından önemi[END_REF] gave an age 0.14 ± 0.02 and 0.11 ± 0.03 Ma K/Ar for these products (Figure 2.6).

Later, 0.083 ± 0.005 Ma dacites (around Hacılar, Figure 2.2) occur as the last dated products of the Erciyes volcanism [START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF]. Şen (1997) stated that an undated debris avalanche is more recent. Kürkçüoğlu [12] suggested that the activity following the dacitic and rhyodacitic units could be followed by alkaline basaltic products. However, there were no available radiometric datings for these volcanic products. New geochronological data were obtained on these basalts s.l.

in the course of this thesis. They are calc-alkaline ER17 (0.045±0.005 Ma), ER26 (0.025±0.008 Ma),ER11 (<0.001 Ma) and alkaline ER29 (0.013±0.005 Ma).

Moreover other young andesites such as ER22 (0.04±0.007 Ma) and ER9 (<0.001

Ma) suggested volcanic activity in historical times, as suggested by Strabo (Ayrancı,1991).

The Southwestern Cappadocia Volcanism

The southwestern volcanism of Cappadocia consists in 3 distinct areas:

1) The Hasandağ is a double-peaked Quaternary stratovolcano. It covers an area of 760 km 2 and the estimated volume is 354 km 3 [START_REF] Aydar | Etude Volcano-Structurale et Magmatologique du Strato-Volcan Hasan Dagı (Anatolie Central-Turquie)[END_REF]. The 2 peaks are 3253 m and 3069 m height, respectively (Photo in Figure 1.3).

2) The Obruk-Zengen dispersed volcanism exhibits basaltic scoria cones (and related lava flows) and maars which spread towards the south and southwest of the main cone of Hasandağ stratovolcano (Photo in Figure 1.4).

3) The Karapınar dispersed volcanism is located at the southwestern extreme part of the studied area, and consists of basaltic scoria cones (and related lava flows)

and maars as Meke (Photo in Fig. 1.5 and Figure 2.5).

The new K/Ar age dating performed on samples belonging to Hasandağ, Obruk-Zengen and Karapınar dispersed volcanism are given in Table 2.4. The sample CK-89-19, of Kayahan Olanca [START_REF] Olanca | Géochimie des laves quaternaires de Cappadoce (Turquie): les appareils monogéniques, Thése 3 eme cycle[END_REF] is considered as equivalent of KA18. These two samples are at the same location and they closely resemble to each other in terms of major element contents. Detailed information about the method of K/Ar dating analysis is given in section 1.4.3.

Hasandağ Basaltic Volcanism

The volcanic history of the Hasandağ stratovolcano is divided in three successive phases: Paleovolcano, Mesovolcano and Neovolcano [START_REF] Aydar | Etude Volcano-Structurale et Magmatologique du Strato-Volcan Hasan Dagı (Anatolie Central-Turquie)[END_REF].

The Paleovolcano is represented by Keçikalesi volcanic units, dated at 13.7±0.3 and 12.4±4 Ma [START_REF] Besang | Radiometrische Altersbestimmungen an Neogenen Eruptivegesteinen der Turkei[END_REF] and by basaltic andesites dated at 7.21±0.09

Ma (K/Ar) [START_REF] Aydar | The geology of Mount Hasan stratovolcano, Central Anatolia, Turkey[END_REF] that flowed in the sedimentary basin. The most voluminous phase of this stage is a rhyolitic ignimbrite dated at 6.31±0.20 Ma [START_REF] Deniel | The Hasan Dagı stratovolcano (Central Anatolia, Turkey): evolution from calc-alkaline to alkaline magmatism in a collision zone[END_REF]. The emplacement of two different ignimbritic units was related to the collapse of a caldera.

The Mesovolcano is represented by andesitic lava flows, domes and block-andash flow deposits. These products filled the first caldera that collapsed at the Paleovolcano stage and created a new volcanic cone. Voluminous rhyodacitic ignimbrites and plinian fallout caused the collapse of the second caldera. The post caldera activity was mainly related to dome growing and block-and-ash flow emplacement, and andesitic lava flows, that built a new cone.

However, the Neovolcano stage, defined as the third stage, started with Pelé-type eruptions that filled the second caldera, as well as the next extrusive and explosive activities producing andesitic and dacitic domes, rhyolitic domes, block-and-ash flows, phreatomagmatic breccias and rhyolitic ignimbrite [START_REF] Aydar | Etude Volcano-Structurale et Magmatologique du Strato-Volcan Hasan Dagı (Anatolie Central-Turquie)[END_REF]. A new and last caldera collapse occurred, filled by domes and related block-and-ash flows. The age interval of the dome and blocky flows near Karakapı village (Figure 2.3) has been determined as 0.08-0.58 Ma [START_REF] Ercan | Hasandağı-Karacadağ Orta Anadolu dolaylarındaki Senozoyik yaşlı volkanizmanin kökeni ve evrimi[END_REF]. In this study, the alkali basalt HA23b (0.543±0.012 Ma) taken from the blocky flow from Mahmutlu Valley (Figure 2.3), can also be placed within this same age interval. This unit is followed by basaltic cones (0.065-0.12 Ma by [START_REF] Ercan | Hasandağı-Karacadağ Orta Anadolu dolaylarındaki Senozoyik yaşlı volkanizmanin kökeni ve evrimi[END_REF] located at the northeast of Gözlükuyu village (Figure 2.3) and lava flows (0.034 Ma by Aydar and Gourgaud 1998 from the Yıprak Hill (Figure 2.3). Our samples alkaline trachy-basalt HA18 (0.105±0.01 Ma), alkali basalts HA19 (0.079±0.004 Ma) and HA20 (0.057±0. 005 Ma), which are located on the same region, northeastern part of the Hasandağ. In this case, it was determined that the age interval for this unit, formed by basaltic scoria cones and related lava flows, was older than the age given by previous workers. The post-caldera activity continued with domes and block-and-ash flows. For this unit, the andesitic dome was dated <0.006 Ma [START_REF] Aydar | The geology of Mount Hasan stratovolcano, Central Anatolia, Turkey[END_REF] and the basaltic andesites located around Dikmen (Figure 2.3) were dated at 0.029-0.033 Ma [START_REF] Kuzucuoğlu | Identifcation and dating of tephra layers from Quaternary sedimantary sequences of Inner Anatolia, Turkey[END_REF]. The alkali basalts HA13b and HA31 located to the north and west of the Hasandağ (Figure 2.3) were dated at 0.019±0.005 Ma and 0.002±0.007 Ma, respectively.

The Obruk-Zengen Dispersed Volcanism

Radiometric ages of the Obruk-Zengen dispersed volcanism are presented in Table 2.4. According to Table 2.4, except calc-alkaline basalt HA17 (0.066±0.007 Ma), the others are older than Hasandağ stratovolcano samples. The oldest two samples are the alkaline basalts HA16 (0.799±0.02 Ma) and HA26 (0.65±0.016 Ma). The others are alkaline basalt HA15 (0.404±0.01Ma), trachybasalt HA14 (0.395±0.01Ma) and calc-alkaline basaltic trachyandesites HA27 (0.331±0.007 Ma).

There are few studies on the basaltic volcanism in the Obruk-Zengen region. One of the previous studies in the region belongs to [START_REF] Ercan | Hasandağı-Karacadağ Orta Anadolu dolaylarındaki Senozoyik yaşlı volkanizmanin kökeni ve evrimi[END_REF] but there are some doubts about the data were given in that study. Consequently, the K-Ar ages given in this study are very important to understand spatio-temporal evaluation of the magmatism in the region.

The Karapınar Dispersed Volcanism

The first volcanic products near Karapınar town, comprised trachyandesitic and andesitic lavas. Karapınar volcanics are basaltic lava flows [START_REF] Ercan | Hasandağı-Karacadağ Orta Anadolu dolaylarındaki Senozoyik yaşlı volkanizmanin kökeni ve evrimi[END_REF], but also explosive products as scoria and phreatomagmatic ejectas. The calcalkali basalt KA18 (0.28±0.0071 Ma) from the Meke Mountain (Figure 2.5) and the calc-alkali basaltic andesite KA21 (0.163±0.01 Ma) are related to basaltic scoria cones and lava flows (Figure 2.8).

The most recent products are basalts of the Meke Maar area [START_REF] Ercan | Hasandağı-Karacadağ Orta Anadolu dolaylarındaki Senozoyik yaşlı volkanizmanin kökeni ve evrimi[END_REF].

There is a 50 m high scoria cone with a small related lava flow (Figure 1.5) inside the Meke maar, which is 900 m long and 550 m wide. The age of the alkali trachybasalt KA19 taken from Meke maar (<0.001 Ma) (Figure 2.5) in this study also verifies the interpretation of [START_REF] Ercan | Hasandağı-Karacadağ Orta Anadolu dolaylarındaki Senozoyik yaşlı volkanizmanin kökeni ve evrimi[END_REF].

During excavations at Çatalhöyük, a picture of an active volcano was found on the walls of a temple which is considered to have been built in 6200 BC [START_REF] Mellart | Çatal Höyük, Staat aus der Steinzeit[END_REF]. The picture, thought to have been drawn 8000-8200 years ago, could depict the Hasandağ in activity or the activity of the Meke volcano that was the closest volcanic area.

Conclusion

New K-Ar dating analyses were carried out on 24 samples of Erciyes stratovolcano, Hasandağ stratovolcano, Obruk-Zengen and Karapınar dispersed volcanisms. Our data contribute significantly to the findings of previous studies carried out in the region and to the age of Quaternary basalts in the area. We emphasize the very young ages (in historical times) of some samples.

1. At Erciyes stratovolcano, according to our new radiometric aging, the oldest sample is related to a basaltic lava flow sample ER13 (1.695±0.037 Ma) which exhibits an alkaline character (trachybasalt). The youngest samples, however, are the calc-alkaline basaltic andesite ER11 (<0.001 Ma) and the andesite ER9 (<0.001 Ma), located at the south of Hacılar (Figure 2.2) Recent ages obtained from the Erciyes stratovolcano and the sample locations were assessed altogether, and we emphasize that most samples aged 0.045 Ma and younger, are located to the northeast and northwest of the volcano.

2. At Hasandağ stratovolcano, the oldest sample is the alkaline basalt, HA23b (0.543±0.012 Ma), located to the northwest of the main cone (Mahmutlu Valley) and the youngest is HA31 the alkaline basalt (0.002±0.007Ma), located to the west of the main cone. When considering all basaltic samples belonging to the Hasandağ stratovolcano, we emphasize that except HA23b, all other samples were ~0.1 Ma or much younger.

3. However, considering the basalts of the Obruk-Zengen dispersed volcanism, it is observed that all samples, except HA17, are older than those of Hasandağ stratovolcano. The oldest sample is from Gaffar Hill, HA16 (0.799±0.02 Ma), and the youngest is HA17 (0.066±0.007 Ma), located to the west of Gaffar Hill (Figure 2.4).

4. The oldest sample taken of the Karapınar dispersed volcanism is calc-alkaline basalt, KA18 (0.28±0.0071 Ma) taken from Meke Mountain, and the youngest is alkaline trachybasalt KA19 (<0.001 Ma), taken from Meke Maar. The number of the studied sample is limited in this area in order to be observed the expected magmatic transition.

Moreover, we emphasize the new very young ages concerning Erciyes, Hasandağ stratovolcanoes and Karapınar area. These new ages reveal that historical eruptions occurred in Cappadocia. Such new data are very important for assessment of volcanic hazards.

MINERALOGY and PETROGRAPHY

In order to determine the mineralogical and petrographical properties of basalts of Cappadocia, 32 samples were collected from Erciyes stratovolcano and 28 samples from Southwestern Cappadocia, including Hasandağ stratovolcano, Obruk-Zengen and Karapınar. Totally 43 thin sections were prepared in the Laboratory "Magmas et Volcans" at Blaise Pascal University (Clermont-Ferrand, France). Informations related to the analytical methods are given in section 1.4.1.

Most of studied samples are basalts s.l. (including trachybasalts, basaltic andesites and rarely andesites), collected as scoria ejecta (from strombolian scoria cones), phreatomagmatic bombs and fragments of lava flows.

The Basalts s.l. of Erciyes Stratovolcano

Optical microscopic studies show that the common mineralogical assemblage of Erciyes samples is plagioclase + olivine + clinopyroxene and oxide minerals.

Sometimes, orthopyroxene occurs. The majority of samples display a porphyritic texture. Some phenocrysts contain glassy inclusions, reaction belts and exhibit strong zoning. Table 3.1 summarizes the description of 21 samples. Plagioclase (Plg) crystals are observed as subhedral, prismatic and sometimes as gnawed, varying from a few hundred microns to few millimeters in size.

Plagioclases are in equilibrium and/or in disequilibrium in the groundmass. We emphasize that both conditions are present together in the samples. Equilibrium plagioclases are present as phenocrysts, microphenocrysts and microlites, and display concentric zoning. However, other plagioclases are mostly observed as phenocrysts and display various disequilibrium textures. Some of them are gnawed and fragmented, or exhibit a clear zone at centre with a sieve texture surrounding this central zone (Figure 3.1) and others display sieve texture only (Figure 3.2). Glomeroporpyhritic texture is also observed. In some thin sections, clinopyroxene (ophitic texture) (Figure 3.3), apatite and oxide minerals are present as inclusions in and around the plagioclase phenocrysts. We observed also olivine crystals which are surrounded by a reaction belt. In some sections, iddingsitization is observed around margins of olivine crystals.

The Basalts s.l. of Southwestern Cappadocia

These basalts s.l. were collected on scoria cones, related lava flows, and maar vents of 3 distinct areas: Hasandağ stratovolcano, Obruk-Zengen dispersed volcanism and Karapinar dispersed volcanism.

The Basalts s.l. of Hasandağ Stratovolcano

Samples of basalt collected on the flanks of Hasandağ stratovolcano revealed their mineralogical assemblage: plagioclase, olivine, clinopyroxene and oxides.

The texture is hypocrystalline and porphyritic. The description of the basalts s.l. of Hasandağ volcano is given in Table 3.2 The matrix is blackish.

Basalts s.l. of the Karapınar Dispersed Volcanism

The samples of Karapınar exhibit the following mineralogical assemblage:

plagioclase, olivine, clinopyroxene and oxides. Their texture is hypocrystalline porphyritic. Table 3.2 shows the description of the Karapınar samples.

Plagioclase (Plg) crystals are subhedral, prismatic and sometimes gnawed. Their size varies between a few hundred microns to millimeters. Plagioclase is formed under equilibrium and disequilibrium conditions, as in KA19 and KA21 samples (Figure 3.16 and 3.17 Table 4.1 shows the compositions of the minerals of the four studied areas.

Representative mineral data set can be found in Appendix.

Mineral Chemistry of the Basalts s.l. of the Erciyes Stratovolcano

Feldspars

Plagioclase (Plg) is the dominant mineral in all Erciyes basaltic (s.l.) rocks.

Plagioclases (An 35-85 ) range in composition (Table 4.1) from albite through andesine to bytownite (Figure 4.1). However, most plagioclases are andesine-labrodorite. Like phenocrysts and microphenocrysts, microlites have a large compositional range An (39-70) (Table 4.1). Generally, plagioclases display normal zoning but in some samples, such as ER1, ER3, ER9, ER10, ER11, ER22, ER27 and ER30, reversed zoning also occurs. As can be seen in Figure 4.1, the An compositions of ER3 and ER10 are very similar. The location of these two samples (Figure 2.2) and their ages are very close to each other (Table 2.3).

Olivine

The Fo% compositions of olivine (Ol) for Erciyes basaltic (s.l.) rocks are listed in

Volcanic Glass

Microprobe analyses of glass can only be carried out on ER27 and ER30

samples. The SiO 2 content is between 66 and 68% in ER27, and 69-71% in ER30.

Mineral Chemistry of the Basalts s.l. of the Southwestern Cappadocia Volcanism

The Hasandağ Stratovolcano

Feldspars

While the composition of plagioclase (Plg) displays a wide range An (37-85) for phenocrysts and microphenocrysts, it is limited An (52-72) for microlites (Table 4.1).

Generally reverse zoning is observed in all samples but normal zoning also occured. Plg is labradorite in composition for the samples HA13b, HA19 and HA20, andesine-labradorite for HA18 and HA23b, labradorite-bytownite for HA31 (Figure 4.5). While the phenocrysts of the youngest sample (HA31) are more calcic, the oldest sample (HA23b) phenocrysts are more sodic (Table 2.4).

Olivine

Olivine occurs as phenocrysts, microphenocrysts and microlites. In

Oxides

The compositions of oxides of all Southwestern Cappadocia samples are plotted in et al., 1988).

4.2.3.The Karapınar Dispersed Volcanism

Feldspars

Plagioclase displays a wide compositional range, An (3-76) for phenocrysts and microcrysts and a more restricted range, An (45-70) for microlites (Table 4.1). The composition of Plg in KA18 and KA19 is andesine to bytownite; in KA21, it is labrodorite and bytownite Plg display generally normal and oscillatory zoning, but reverse-zoned plagioclase phenocrysts are observed in contemporaneous samples KA18 and KA21 (Table 2.4). Equilibrium and disequilibrum features are both observed in all samples. The youngest sample KA19 (<0.001 Ma) has a wide range olivine composition for phenocyrsts and microcrysts (Fo% 68-86). However, the others are ranging between Fo% 77 and 89. Considering the olivine microlites, the composition of oldest sample KA18 (0.280±0.0071 Ma) has Fo%( 47-56 ) slightly lower than the KA19 and KA21, Fo%( 62-70 ). All samples are normally zoned with Fo-rich cores.

Clinopyroxene

All Clinopyroxenes (Cpx) are diopside and augite in composition (Figures 4.14

Crystal-Liquid Equilibrium

According to [START_REF] Damasceno | Mineral chemistry of midly alkaline basalts from the 25 Ma Mont Crozier section, Kerguelen Archipelago: constraints on phenocryst crystallization environments[END_REF], magmatic systems are sensitive to changes in the composition of the phenocrysts and the mineral-liquid equilibrium.

If phenocrysts and microcrysts are in equilibrium with liquid, they can be used to estimate the temperature (and sometimes pressure) of the magma.

Erciyes Stratovolcano

Olivine-Liquid Equilibrium

Chemical equilibrium between olivine and liquid has been the subject of considerable attention. In multi-component systems, the temperature dependence of Mg and Fe partitioning between olivine and liquid are very similar [START_REF] Toplis | The thermodynamics of iron and magnesium partitioning between olivine and liquid: criteria for assessing and predicting equilibrium in natural and experimantal systems[END_REF].

The ratio of the partition coefficients of iron and magnesium is called the exchange coefficient:

Where X represents the molar fractions of respective components in either liquid (liq) or olivine (ol). The distribution coefficient between olivine and basaltic liquid is 0.3 ± 0.03 and is independed of temperature. This constant presented by [START_REF] Roeder | Olivine-liquid equilibrium[END_REF] by experimental studies.

Clinopyroxene-Liquid Equilibrium

The Fe/Mg exchange distribution coefficient between clinopyroxene and basaltic liquid is less constrained than that of olivine-liquid, due to the presence of ferric iron in clinopyroxene and in the melt [START_REF] Damasceno | Mineral chemistry of midly alkaline basalts from the 25 Ma Mont Crozier section, Kerguelen Archipelago: constraints on phenocryst crystallization environments[END_REF]. However, according to experimental studies [START_REF] Grove | Fractionation of pyroxene-phric MORB at low pressure: An experiment study[END_REF][START_REF] Toplis | An experimental study of the influence of oxygen fugacity on Fe-Ti oxide stability, phase relations and mineral-melt equilibria in ferro-basaltic systems[END_REF] the distribution coefficient between clinopyroxene and the basaltic liquid is 0.23 ± 0.05 [START_REF] Hoover | Liquidus relations and Mg-Fe partitioning in part of the system Mg2SiO4-Fe2SiO4-CaMgSi2O6-CaFeSi2O6-KalSi3O8-SiO2[END_REF][START_REF] Damasceno | Mineral chemistry of midly alkaline basalts from the 25 Ma Mont Crozier section, Kerguelen Archipelago: constraints on phenocryst crystallization environments[END_REF]. Figure 4.16

illustrates the relationship between Mg-numbers of whole rock and clinopyroxenes.

Equilibrium field is drawn according to KD = 0.23 ± 0.05 [START_REF] Toplis | An experimental study of the influence of oxygen fugacity on Fe-Ti oxide stability, phase relations and mineral-melt equilibria in ferro-basaltic systems[END_REF].

Feldspar -Liquid Equilibrium

In Figure 4.17, some of the plagioclase phenocrysts of the samples ER9, ER11, ER20, ER22, ER26, ER27, ER30 and ER32 are in the liquid equilibrium field (Figure 4.17). The conditions are assumed under almost dry (KD = 1-3) and at low pressure (<2 kbar) [START_REF] Sisson | Experimental investigations of the role of H2= in calc-alkaline differentiation and subduction zone magmatism[END_REF][START_REF] Feeley | Compositional and dynamic controls on mafic-silicic magma interractions at continental arc volcanoes: evidence from Cordon El Guadal, Tatara-San Pablo Complex, Chile[END_REF][START_REF] Ferla | Evidence of magma mixing in the "Daly Gap" of alkaline suites: A case study from the enclaves of Pantelleria (Italy)[END_REF].

On the other hand, the composition of plg microcrysts and microlites of ER3, ER10, ER13, ER17 and ER29 are out of the equilibrium field. As can be seen from the Figure 4.17, the rim composition of ER1 is plotted in the equilibrium field while the cores are out of that field. As mentioned before in the section 4.3.1.1, in multi-component systems, the temperature dependence of Mg and Fe partitioning between olivine and liquid is very similar [START_REF] Toplis | The thermodynamics of iron and magnesium partitioning between olivine and liquid: criteria for assessing and predicting equilibrium in natural and experimantal systems[END_REF] and the distribution coefficient between olivine and basaltic liquid is experimentally presented 0.3 ± 0.03 [START_REF] Roeder | Olivine-liquid equilibrium[END_REF]. Generally Hasandag samples are more mafic than the Erciyes samples (48 %< SiO2 <57%). So, the amount of olivine crystals in Hasandağ samples is higher than in Erciyes and their size is quite big, ranging between few µm to mm.

According to the diagrams, Hasandag samples are rather in equilibrium with melt.

 Obruk-Zengen

As mentioned in chapter 3, Olivine crystals exhibit equilibrium and disequilibrium features (Figure 3.12). Mostly, the phenocrysts rim and core compositions are in the equilibrium field (Figure 4.18). On the other hand microlites are out of equilibrium as expected. Except HA27, the others % Fo are high. HA27 is the most differentiated samples among Obruk-Zengen samples.

Karapınar

The phenocryst compositions of all Karapınar samples are mostly in the equilibrium field. The youngest sample, KA19 (Table 2.4) is different from the KA18 and KA21. The Mg number and the %Fo values are lower than the others.

Clinopyroxene-Liquid Equilibrium

 Hasandağ stratovolcano

In Figure 4.19, none of the clinopyroxenes phenocrysts, microphenocrysts and microlites is in the equilibrium field. This information is in accord with the mineralogical-petrographical observations. The serpentinization of Cpx is common feature of this group (Table 3.2).

 Obruk-Zengen

Except HA27 Cpx microcrysts, none of the other Cpx minerals of the Obruk-Zengen volcanics are plotted in the equilibrium field (Figure 4.19). According to mineralogical data, clinopyroxenes are mainly microlites and serpentinization occurs (Table 3.2).

 Karapınar

As seen from the Figure 4.19, some of the clinopyroxenes phenocrysts in KA19 are plotted in the equilibrium field. On the other hand, none of the Cpx phenocrysts and/or microcrysts of KA18 and KA21 are in the equilibrium field. As a result of the mineralogical observations only KA21 has some oxidation (Table 3.2). Mineral-mineral and mineral-liquid temperature estimations were performed for each rock sample. According to the chemistry of the samples, it was not possible to measure glass analyses for each rock samples. For this reason, instead of glass compositions, the whole rock compositions were used for liquid composition.

The geothermometer calculations were done by the help of the [START_REF] Putirka | Thermometers and Barometers for Volcanic Systems, Minerals, Inclusions and Volcanic Processes, Reviews in Mineralogy and Geochemistry[END_REF].

Erciyes Stratovolcano

The geothermometer calculations were performed on olivine-liquid, clinopyroxeneliquid, two-pyroxene and plagioclase-liquid pairs. Estimated geothermometers and the evolution of temperatures with changing SiO 2 contents are in Table 4.2 and The equilibrium conditions of considered minerals are the most important parameter for geothermometer calculations [START_REF] Putirka | Thermometers and Barometers for Volcanic Systems, Minerals, Inclusions and Volcanic Processes, Reviews in Mineralogy and Geochemistry[END_REF]. [START_REF] Putirka | Ambient and excess mantle temperatures, olivine thermometry, and active vs. passive upwelling[END_REF] present many equations for geothermometer calculations but the Equation 22gives the best estimates when water is present and H 2 O ranges from 0-18.6% for the test data set [START_REF] Putirka | Thermometers and Barometers for Volcanic Systems, Minerals, Inclusions and Volcanic Processes, Reviews in Mineralogy and Geochemistry[END_REF]. Accordingly Equation 22is chosen for Erciyes samples. The water content of Erciyes basaltic samples is < 1% (Table 2.2).

Estimated temperatures of the less differentiated samples (ER13, ER1, ER3 and ER29) vary between 1212 and 1260 o C (Table 4.2). On the other hand, the estimated temperature of more differentiated samples ranges between 1160 and 1215 o C (Table 4.2). Less differentiated samples estimated temperatures are higher than that of the differentiated samples.

Clinopyroxene-Liquid Geothermometer

Clinopyroxene is the common mineral in igneous rocks and it is useful for understanding the magmatic processes and crystallization conditions [START_REF] Masotta | Clinopyroxeneliquid thermometers and barometers specific to alkaline differentiated magmas[END_REF]. For this reason many models asserted before by [START_REF] Nimis | A clinopyroxene geobarometer for basaltic systems based on crystals-structure modeling[END_REF][START_REF] Nimis | Clinopyroxene geobarometry of magmatic rocks, Part 1: an expanded structural geobarometer for anhydrous and hydrous basic and ultrabasic systems[END_REF][START_REF] Nimis | Single clinopyroxene thermobarometry for garnet peridotites, Part 1: Calibration and testing of a Cr-İn cpx barometer and an enstatite-in-cpx thermometer[END_REF][START_REF] Putirka | Thermobarometry of mafic igneous rocks based on clinopyroxene-liquid equilibria, 0-30 kbar[END_REF][START_REF] Putirka | New clinopyroxene-liquid thermometers for mafic, evolved, and volatile-bearing lava compositions, with applications to lavas from Tibet and the Snake River Plain, Idaho[END_REF][START_REF] Putirka | Thermometers and Barometers for Volcanic Systems, Minerals, Inclusions and Volcanic Processes, Reviews in Mineralogy and Geochemistry[END_REF].

The models of thermometer or barometers use either clinopyroxene alone or clinopyroxene-liquid equilibria. In this work we use clinopyroxene-liquid equilibria [START_REF] Putirka | Thermometers and Barometers for Volcanic Systems, Minerals, Inclusions and Volcanic Processes, Reviews in Mineralogy and Geochemistry[END_REF]. In Figure 4

Plagioclase-Liquid Geothermometer

The first plagioclase-liquid geothermometer was presented by [START_REF] Kudo | An igneous plagioclase thermometer[END_REF]. [106]. Many previous workers (e.g., [START_REF] Mathez | Refinement of the Kudo-Weill plagioclase and its applications to basaltic rocks[END_REF][START_REF] Drake | Plagioclase-melt equilibria[END_REF][START_REF] Loomis | An emprical model for plagioclase equilibrium in hydrous melts[END_REF][START_REF] Glazner | Activities of olivine and plagioclase components in silicate melts and their application to geothermometry[END_REF][START_REF] Ariskin | Equilibria thermometry between plagioclases and basalt or andesite magmas[END_REF][START_REF] Marsh | On plagioclase thermometry in island-arc rocks: experiments and theory, Fluid-Mineral interactions[END_REF]) showed attention about plagioclase thermometry. Later on, [START_REF] Putirka | Igneous thermometers and barometers based on plagioclase + liquid equilibria: tests of some existing models and new calibrations[END_REF] stated that the calibration of [START_REF] Sugawara | Ferric iron partitioning between plagioclase ans silicate liquid: thermodynamics and petrological applications[END_REF] and the MELTS/pMELTS models of [START_REF] Ghiorso | The pMELTS: a revision of MELTS for improved calculation of phase relations and major element partitioning related to partial melting of the mantle to 3 Gpa[END_REF] are the most accurate predictors of T for existing models. However, these models failed at low T (<1100 °C) and for hydrous systems. According to [START_REF] Putirka | Thermometers and Barometers for Volcanic Systems, Minerals, Inclusions and Volcanic Processes, Reviews in Mineralogy and Geochemistry[END_REF],as a test for plagioclase-liquid equilibrium, T from Equations ( 23) or (24a) can be compared to the T required for a liquid to reach plagioclase saturation. Due to that, Equation 23 was used for plagioclase-liquid geothermometer. The samples with plagioclases in equilibrium are selected for plagioclase-liquid geothermometer calculations (Figure 4.17). The minimum estimated temperature is 1146 o C for ER30 and the maximum temperature is 1183 o C for ER26 (Table 4.2).

The Southwestern Cappadocia

The geothermometer calculations were performed on olivine-liquid, plagioclase-

 Karapınar

According to olivine-liquid equilibria, except KA19 the calculations were performed with the samples KA18 and KA21 (Figure 4.18). As can be seen from the

 Karapınar

In Karapınar, KA19 is the only sample that exhibits cpx phenocrysts in equilibrium (Figure 4.19). The calculated temperature of KA19 is 1172 o C. The other two samples, KA18 and KA21 are out of the equilibrium field.

For this reason there isn't any cpx geothermometer calculation made for these samples. The estimated barometer and the depth of KA19 is 5.30 kbar and 21 km, respectively.

Plagioclase -liquid geothermometer

The models of plagioclase-liquid pairs by previous workers indicated in section 4.4.1.4. By using plagioclase-liquid equilibria, estimated geothermometers are calculated (Table 4.3).

 Hasandag stratovolcano

HA31 is the only sample under equilibrium condition (Figure 4.20) and its estimated temperature is 1250 o C (Table 4.3).

 Obruk-Zengen

The plg phenocrysts and microcrysts of the samples HA14, HA26 and HA27 are in 4.3).

 Karapınar

Except KA18, phenocrysts and microcrysts of KA19 and KA21 are in the equilibrium field (Figure 4.20). In Table 4.3, the results are 1228 o C for KA19 and 1171 o C for KA21.

Conclusion

According to the microprobe analyses, we are trying to find out the conditions and constraints of the magma. Estimated temperatures, barometers and depths are calculated (Table 4.4). A summary of mineral chemistry and mineralogy and petrography is presented below. 1. Plagioclase is the common mineral of all four studied areas. Mostly, plg occurs as a phenocryst and ES differs from the 3 other studied areas with its wide range plg phenocrysts.

2. Normal and reverse zoning plg occur in ES, OZ and K.

3. Erciyes stratovolcano is the only region that has opx.

4. The occurrence of both plg and ol, in equilibrium and disequilibrium, emphasizes that the genesis conditions were variable and related to magma mixing processes.

5. Estimated temperatures and barometers are proposed are 10.5-17 km, 18 km, 19-28 km and 21 km for ES, HS, OZ and K, respectively (Table 4.4).

According to these results, the depths of ES are shallower than for the other studied areas. OZ gives the highest cpx-liq temperature, pressure and depth.

6. The evolution of temperatures does not change systematically with SiO 2 contents in the 4 studied areas.

7. The mean value of ol-liq temperatures and depths are increasing from NE to SW.

All these differences may be explained by multistage crystallization of minerals in magma chambers located at different depths.

GEOCHEMISTRY

Detailed geochemical features of the subjected associations from studied area, including isotopic data, are given in the following sections with their interpretations.

Representative samples for major, trace and rare earth elements analysis were carried out from Erciyes stratovolcano (ES) (n=19), Southwestern Cappadocia Volcanism (n=15), that embraces the Hasandağ stratovolcano (HS) (n=6), Obruk-Zengen (OZ) (n=6), and Karapınar (K) (n=3) areas. Moreover, 29 Sr-Nd, 28 Pb and 28 O isotopic analyses were performed and discussed in detail below.

Procedures of the analytical techniques can be found in the section 1.4.2.

Major, Trace and Rare Earth Element (REE) Analysis

In this section, major, trace and REE analytical results, which were separated from the studied field by their composition and their locations, will be given in individual sub-sections.

Erciyes Stratovolcano

Major element and CIPW normative data are given in Table 5. According to the alkaline-subalkaline separation line [START_REF] Miyashiro | Nature of alkalic rock series[END_REF] In the Harker diagrams, the trends emphasize the fractional crystallization process.

In the initial phase, olivine, pyroxene, Ca-plagioclase and opaque minerals (apatite, magnetite, and ilmenite) were formed. In the later phases, the formation of amphibole occurs.

Trace element compositions of 19 samples from Erciyes are shown in Table 5.2.

Selected trace elements vs. Th are proposed, according to the more stable characteristic of Th, compared to the other incompatible elements such as Rb, K, Ba, etc. (Figure 5.5). As concluded for major element distribution, trace elements diagrams also emphasize the predominant role of fractional crystallization.

Primitive Mantle (PM) [START_REF] Sun | Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes[END_REF]) normalized multi-element diagrams are given in Figure 5.6 a-b. To understand similarities or differences between the samples, we separated LDDS (Less differentiated dated samples)

and MDDS (More differentiated dated samples). LDDS (ER1, ER3, ER10, ER13 and ER 29) and MDDS (ER2, ER9, ER11, ER17, ER20, ER22, ER25, ER26, ER27, ER30, ER32) ages (Table 2. Enrichment in highly incompatible element contents such as Ba, Rb, Th and K is a typical characteristic of active continental margins or within plate magmatisms [START_REF] Wilson | Igneous Petrogenesis[END_REF]. During subduction, the subducted plate plunges into the mantle and partially melts. This partial melting favors enrichment in volatile components and fluids [START_REF] Wilson | Igneous Petrogenesis[END_REF]. Highly incompatible elements (such as Ba, Rb, Th and K) will merge into the melt. High-Field Strength (HFS) elements will be kept in the mineral stable phases that remain in the source after partial melting, such as rutile, titanite, ilmenite and apatite [START_REF] Gill | Orogenic andesites and Plate tectonics[END_REF][START_REF] Fitton | The role of lithospheric mantle in the generation of Late Cenezoic basic magmas in the Western United States[END_REF][START_REF] Mcculloch | Geochemical and geodynamic constraints on subduction zone magmatism[END_REF]. According to [START_REF] Lustrino | The circum-Mediterranean anorogenic Cenozoic igneous province[END_REF], negative Nb-Ta and positive Pb anomalies can be related to two different processes: i) shallow level crustal contamination by addition of subducted sediment into the mantle source, ii) fluidinduced enrichment of the elements adjacent to Nb-Ta in the trace element pattern (will be discussed in 6th chapter).

Besides, the elements trends in spidergrams or multielement diagrams, the element ratios such as Ba/Nb, Ce/Y, La/Nb helps to understand the features of the magmas.

According to [START_REF] Fitton | The role of lithospheric mantle in the generation of Late Cenezoic basic magmas in the Western United States[END_REF], the ratio Ba/Nb >28 is characteristic of arc magmatisms. Ba/Nb ratios vary between 17.46 to 21.69 in LDDS and 21.53 to 26.73 in MDDS (Table 5.3). According to [START_REF] Shaw | Petrogenesis of the Largest Intraplate Volcanic Field on the Arabian Plate (Jordan): a Mixed Lithosphere-Asthenosphere Source Activated by Lithospheric Extension[END_REF], the lithospheric mantle comprises spinel and garnet. However, the mantle melting beneath intra-plate OIB probably begins in a garnet-bearing peridotite [START_REF] Niu | The origin of intraplate ocean island basalts (OIB): the lid effect and its geodynamic implications[END_REF] In According to [START_REF] Sun | Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes[END_REF], in LDDS group, the lowest ratio of (La/Yb) is in ER13 (4.65), and slightly higher ratios between 6.76 and 6.39 are in ER3 and ER10's respectively (Table 5.3). ER1 and ER29 have relatively highest ratios of (La/Yb) N (10.26-10.24). In MDDS, (La/Yb) N ratios vary between 7.56 to 9.08, except ER30 (6.86) (Table 5.3).

b Low Zr/Ba, high Th/Y, and Ta/Th ratios are related to low grade partial melting.

Therefore, in LDDSs these ratios are changing between 0.41 and 1.16 for Zr/Ba, 0.05 and 0.32 for Th/Y, 0.14 and 0.56 for Ta/Th. The sample ER13 has the highest Zr/Ba and Ta/Th ratios (Table 5.3) and the lowest Th/Y. On other hand, in MDDSs they vary between 0.42 and 0.67 for Zr/Ba, 0.13 and 0.27 for Th/Y, 0.13-0 and 38

for Ta/Th. Based on this ratio variance, different graded partial melting occurred in these two groups.

According to [START_REF] Fitton | The role of lithospheric mantle in the generation of Late Cenezoic basic magmas in the Western United States[END_REF], LREEs are more incompatible than HREEs and they prefer entering into molten phase during igneous differentiation or partial melting. The enrichment observed in LREEs may occur at low grade partial melting or crustal contamination. The grade of partial melting that occurred in the mantle may be obtained by using high and low LREE/HREE ratios. LREE/HREE enrichment may particularly followed through the ratio of (La/Yb) N . High (La/Yb) N ratio gives us the idea that alkaline basalts occurred from an enriched mantle source of magma due to a low grade partial melting.

Southwestern Cappadocia Volcanism

Southwestern Cappadocia Volcanism is examined in 3 different locations: i)

Hasandağ stratovolcano (HS) and ii) Obruk-Zengen (OZ), iii) Karapınar (K) dispersed volcanism. In the following section, geochemical results including major, trace, REE, and isotopic data of the Southwestern Cappadocia Volcanism will be given by using the names above.

Major element and CIPW normative values of 6 samples from HS, 5 samples from OZ and 3 samples from K are obtained and given in Table 5.4. HS samples exhibit basic characteristic (49% < SiO 2 < 51%) with the MgO values of 6% < MgO < 9%.

(Table 5.4). In OZ and K samples, basic character is also observed: 49% < SiO 2 < 56% and 49% < SiO 2 < 53% respectively, (Table 5.4).

In the nomenclature diagram of Le [START_REF] Bas | A Chemical Classification of Volcanic Rocks Based on the Total Alkali -Silica Diagram[END_REF] In HS, CIPW norm values indicate occurrence of nepheline normative, except the hypersthene normative of HA18 and HA23b samples (Table 5.4). All samples exhibit high amount of plagioclase normative, diopside, olivine and low amount of normative alkaline feldspar, magnetite, ilmenite and apatite (Table 5.4).

Occurrence of normative nepheline is dominant in OZ, except HA27 sample, which is one of the most differentiated samples and display a calcalkaline characteristic with normative quartz and hypersthene (Table 5.4).

In K also, all of the samples consist of dominantly normative plagioclase, diopside, olivine and low amount of alkaline feldspar, magnetite, ilmenite and apatite minerals. In KA21 sample indicates hypersthene normative, but KA18 and KA19

have nepheline normative (Table 5.4). In contrast to HS, the samples of OZ and K present nearly no systematic trends (Figure 5.11). Irregular scatters in the diagrams are seen and only significant increase in U vs. Th is noted in the OZ group (Figure 5.11). This evidence with major elements variation diagram clearly addresses that the fractional crystallization was not effective in the genesis of OZ magmas.

Aluminous data (Al

Similar to OZ group, samples of K area display no significant trends; however a slightly increase in Ba, Rb and a noticeable positive trend in U with negative Sr, Eu and Y trends are observed (Figure 5.11).

Mg# contents of the Southwestern Cappadocia samples vary in the range of 66 to 72. Relatively to the OZ and K dispersed volcanism, the HS samples display slightly more effect of fractional crystallization. However in the whole associations, it is noted that these samples are derived from peridotite according to their high Mg# > 68-70 range [START_REF] Frey | Integrated models of basalt petrogenesis study of quartz tholeiited to olivine melilities from south eastern Australia Utilizing geochemical and experimental petrological data[END_REF] and fractional crystallization is not the main process during the magma genesis.

Primitive mantle (PM) normalized multi-element diagrams of HS, OZ and K areas are compared to OIB and E-MORB (Figure 5. 5.6). The ratios of Ba/Nb are 28 for HA31 sample and lower than 28 for all other samples in the HS group. In addition to that, a Ba/Nb value are 33 for the most primitive sample and 36 for the most differentiated sample of HA27 in OZ group and is not higher in K group.

Consequently, these samples mentioned above are more likely linked to the partial melting of a non homogeneous mantle, which was metasomatized by an ancient subduction process rather than a stronger one and/or experienced a crustal contamination during its formation. Ce/Y ratios of the HS and OZ groups vary between 1.88 and 2.72, and 1.96-2.92 respectively. Zr/Nb ratios range from 9.66 to13.34 and 10.75 to 13.75 for HS and OZ groups (Table 5.6). In the HS group, La/Nb values are between 1.72 and 2.22, and are relatively similar to the 1.63 to 2.33 related to the OZ group, in which lithospheric mantle source values (La/Nb>1) are reported in the literature (De Paolo and Daley, 2000).

In K group, Ce/Y, Zr/Nb, and La/Nb values are 2. 29-2.82, 13.19-13.86, 2.63-3.53 respectively (Table 5.6). Variable low Zr/Ba ratios (0.32 to 0.65) in HS, OZ and K groups point out a lithospheric source enriched by Ba and mixed to the melting during the subduction processes, as reported in [START_REF] Menzies | Enriched and depleted source components for tholeiitic and alkaline lavas from Zuni-Bandera, New Mexico: Inferences about intraplate processes and stratified lithosphere[END_REF]. In addition, lack of the depletion in garnet phases from the multi-element diagrams (Figure 5.12) related to the lower amount of Y and Yb, favor shallow lithospheric source for the Southwestern Cappadocia Volcanism.

The samples of the whole Southwestern Cappadocia Volcanism, which are normalized to PM, exhibit typical enrichment in LILEs (Rb, Ba, Th, U, K, Sr)

indicating an active continental margin magmatisms environment, Nevertheless, OZ and K are more enriched in these elements, and moreover a negative anomaly in Nb, Ta, Ti and P generally occurs, related to the accretion of the fluids resulting of the dehydration of a subducted plate [START_REF] Saunders | The geochemistry of basalts from a back-arc spreading centre in the East Scotia Sea[END_REF][START_REF] Pearce | Trace element characteristics of lavas from destructive plate boundaries[END_REF][START_REF] Wilson | Igneous Petrogenesis[END_REF]. Negative anomaly in HFS element increase relatively from HS to K (Figure 5.12).

Chondrite normalized [START_REF] Sun | Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes[END_REF]

Isotope Geochemistry

Isotopic compositions (Sr-Nd-Pb-O) of the Erciyes stratovolcano (ES) and the Southwestern Cappadocia Volcanism, which consists of Hasandağ stratovolcano (HS), Obruk-Zengen (OZ), Karapınar (K) were analyzed and details of the results are given below. The detailed steps of the regarded analytical techniques can be found in the section 1.4.2. Isotopic features of the samples in the region will be presented related to their region following the same order as in the major, trace and REE analysis section 5.1.

Sr-Nd-Pb-O Isotope Geochemistry

This section will be given in 2 major groups as previously given in major, trace and REE elements. These groups are: i) ES, which is presented in 2 groups as LDDS (Less differentiated dated samples) and MDDS (More differentiated dated samples), ii) Southwestern Cappadocia volcanism (HS, OZ and K).

Erciyes Stratovolcano

From dated 14 samples of the ES with 2 different sections of the sample ER27

were analyzed for Sr-Nd isotopes, the results are given in Dewey et al., (1990); Kerguelen oceanic island basalts; [START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF]; MORB, [START_REF] Cohen | The lead, neodymium and strontium isotopic structure of ocean ridge basalts[END_REF]; Big Pine, Ormerod et al., (1988); Andean basaltic rocks, [START_REF] Hickey | Multiple source basaltic arcrocks from the southern volcanic zone of the Andes (34o-41oS): trace element and isotopic evidence for contributions from subducted oceanic crust[END_REF]; West Anatolian basaltic volcanics, [START_REF] Aldanmaz | Petrogenetic evolution of Late Cenozoic post-collision volcanism in Western Anatolia,Turkey[END_REF]; basalts form Mount Nemrut -Eastern Anatolia-, Çubukçu, ( 2008 show more likely similar values with Kerguelen island basalts [START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF] and Society island lavas (Dewey et al., 1990). Kerguelen Islands' samples have a higher 87 Sr/ 86 Sr and lower 143 Nd/ 144 Nd values than oceanic island basalts (OIB)

and bulk earth composition. It's unlikely that these volcanics were contaminated from continental crust especially considering their oceanic derivation environment.

This is related to the enriched parts of the mantle from the volatiles and mantle metasomatism during the subduction [START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF]. [START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF]Dewey et al., 1990;[START_REF] Cohen | The lead, neodymium and strontium isotopic structure of ocean ridge basalts[END_REF]Ormerod et al.,1988;[START_REF] Hickey | Multiple source basaltic arcrocks from the southern volcanic zone of the Andes (34o-41oS): trace element and isotopic evidence for contributions from subducted oceanic crust[END_REF][START_REF] Aldanmaz | Petrogenetic evolution of Late Cenozoic post-collision volcanism in Western Anatolia,Turkey[END_REF]Çubukçu, 2008. Mantle array andBulk Earth, Wassenburg et al., (1981) and [START_REF] Faure | Principles of isotope geology[END_REF] In MDDS, all samples present calcalkaline features and except ER32 they have limited age interval ( Another same age interval sample couples are ER17 and ER22. ER22 is more radiogenic in terms of 87 Sr/ 86 Sr than ER17 (Figure 5.15b). No significant differences in Nd-isotopes (Figure 5.15d).

According to the age vs. Sr-Nd isotope diagrams, slightly different trends are seen between LDDS and MDDS groups (Figure 5.15). LDDS age interval is more extended than MDDS (Table 5.7 Based on analysis of O-isotope data for ES samples, δ 18 O‰ variation of + 6.00 to +7.12‰ points out these values are slightly higher than MORB (+ 5.3-6.2‰ [142]), and OIB (+4,9-6‰ Eiler et al.,1996a ;[START_REF] Zindler | Chemical Geodynamics[END_REF] values, moreover these values do not fit in the scattered δ 18 O values (+4,8-12‰ [START_REF] Harmon | Pertrogenesis of Andean andesites from combined O-Sr isotope relationships[END_REF]Davidson and Harmon,1989) of subduction related volcanism. Based on similar age samples, no significant variation is observed, besides negative correlation in LDDS is more likely related to a contamination resulted by the lower Pb bearing crustal material [START_REF] Ellam | Oxygen isotope constrains on the crustal contribution to the subduction-related magmatism of the Aeolian Islands, southern Italy[END_REF].

Southwestern Cappadocia Volcanism

Sr, Nd, Pb, and O-isotope analysis of the Southwestern Cappadocia Volcanism consisting of three different volcanic areas (HS, OZ and K) are given in Table 5.8.

Based upon isotopic analytical results of the 87 Sr/ 86 Sr and 143 Nd/ 144 Nd isotopic geochemistry, ratios for HS vary (0.704625-0.704976; 0.512657-0.512718), OZ (0.704153-0.704711; 0.512723-0.512826), and K (0.705188-0.705502; 0.512602-0.512633), respectively (Table 5.8). HS samples have a higher, and exhibit similarities with Kerguelen [START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF] and Society island (Dewey et al., 1990) earth from the comparison data that are given in Figure 5.25. In addition to this, they show similarities with Kerguelen [START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF], Society island (Dewey et al., 1990) and And basalts [START_REF] Hickey | Multiple source basaltic arcrocks from the southern volcanic zone of the Andes (34o-41oS): trace element and isotopic evidence for contributions from subducted oceanic crust[END_REF]. [START_REF] Wilson | Igneous Petrogenesis[END_REF]; [START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF]Dewey et al., 1990;[START_REF] Cohen | The lead, neodymium and strontium isotopic structure of ocean ridge basalts[END_REF]Ormerod et al., 1988;[START_REF] Hickey | Multiple source basaltic arcrocks from the southern volcanic zone of the Andes (34o-41oS): trace element and isotopic evidence for contributions from subducted oceanic crust[END_REF][START_REF] Aldanmaz | Petrogenetic evolution of Late Cenozoic post-collision volcanism in Western Anatolia,Turkey[END_REF][START_REF] Çubukçu | Nemrut Stratovolkanının petrolojik Evrimi: Çarpışma Bölgesinde Peralkali Magmatizma[END_REF] Mantle array and Bulk Earth belong to Wassenburg et al., (1981) and [START_REF] Faure | Principles of isotope geology[END_REF], EMI and EMII, to [START_REF] Zindler | Chemical Geodynamics[END_REF])

In the spatio-temporal evolution diagrams, as seen in Sr, and Nd-isotopes vs. Age 5.8). Pb-isotope ratios between (18.86-18.91); (15.64-15.66); (38.89-38.98) and (18.97-19.00); (15.69-15.70); (39.13-39.19) are seen in OZ and K samples, respectively (Table 5.8). All the samples of the Southwestern Cappadocia Volcanism are plotted above Northern Hemisphere Reference Line (NHRL) (Figure 5.28). Samples of this volcanism are likely seen in the EMII area, which is defined as the mantle area enriched by sediments, continental crust, altered oceanic crust [START_REF] Rollinson | Using Geochemical Data: Evaluation, Presentation, Interpretation[END_REF][START_REF] Zindler | Chemical Geodynamics[END_REF]. 5.8. O-isotope values range from (6.62-6.79); (5.88-7.27); and (6.31-6.75) in HS, OZ and K, respectively (Table 5.8). According to [START_REF] Ito | The O,Sr, Nd and Pb isotope geochemistry of MORB[END_REF], O-isotope values between 5.3-6.2‰ indicate MORB like signature.

In the papers of [START_REF] Eiler | Oxygen isotope variations in ocean island basalt phenocrystals[END_REF] and [START_REF] Zindler | Chemical Geodynamics[END_REF] 4.9-6‰ O-isotope values remark OIB areas.

For subduction volcanism, [START_REF] Harmon | Pertrogenesis of Andean andesites from combined O-Sr isotope relationships[END_REF] and [START_REF] Davidson | Oxygen isotope constraints on the petrogenesis of volcanic arc magmas from Martnique, Lesser Antilles[END_REF] suggest 4.8-12‰ O-isotope values. Moreover, according to [START_REF] Eiler | Oxygen Isotope Variations of Basaltic Lavas and Upper Mantle Rocks, Stable isotope geochemistry[END_REF], typical upper mantle and oceanic basalts' δ 18 O‰ values are also in between 6-7%.

According to literature mentioned above, HS, OZ and K groups indicate upper mantle and oceanic basalt values.

In δ 18 O‰ VSMOW vs. Age (ka) diagram (Figure 5.33), HS group present no significant change from oldest to youngest samples. Slight differences between inter and intra groups is noted in the samples of the Southwestern Cappadocia Volcanism, however this doesn't affect the evolution history of the group (Figure 5.33). However, in the diagram of δ 18 O‰ VSMOW vs. 87 Sr/ 86 Sr, clear discrimination due to Sr-isotope variation between the sub-groups of Southwestern Cappadocia Volcanism is seen (Figure 5.34). 2. All samples exhibit normative Plg, diopside and accessory minerals (apatite, magnetite and ilmenite) (Table 5.1). ER13 sample exhibits nepheline normative while the others exhibit normative hypersthene. All samples exhibit normative quartz, except the samples ER10, ER13 and ER29, which are olivine normative.

3.

Harker diagrams emphasize the predominant role of fractional crystallization. 8. The low Zr/Ba, high Th/Y, and Ta/Th ratios are related to low grade partial melting. Based on different ratios of this ratio variance, different graded partial melting occurred in these two groups.

9. The samples of HS exhibit basic characteristic (49% < SiO 2 < 51%), OZ and K samples are basic in compositions 49% < SiO 2 < 56 % and 49% < SiO 2 < 53% respectively, (Table 5.4). 12. In HS, all samples exhibit high amount of plagioclase normative, diopside, olivine and low amount of normative alkaline feldspar, magnetite, ilmenite and apatit Occurrence of normative nepheline is dominant in OZ and in K, all of the samples consist of dominantly normative plagioclase, diopside, olivine and low amount of alkaline feldspar, magnetite, ilmenite and apatite minerals (Table 5.4).

According to major element distribution of the Southwestern Cappadocia

Volcanism, HS experienced strong fractional crystallization even more dominant compared to ES. However, this strong fractional crystallization pattern is not observed in OZ and K dispersed volcanism.

14. Primitive mantle (PM) normalized multi-element diagrams of HS, OZ and K exhibit enrichment in LILEs. OZ and K have negative anomaly in Nb, Ta, Ti and P and negative anomalies in HFS element increase relatively from HS to K (Figure 5.12 a-b-c).

15. Chondrite normalized REE diagrams show that HS, OZ and K are enriched in LREE more than HREE (Figure 5.13).

16. Variable low Zr/Ba ratios in HS, OZ and K groups point out a lithospheric source enriched by Ba and mixed to the melting during the subduction processes, as reported in Menzies et al. [132].

17. Lack of the depletion in garnet phases from the multi-element diagrams (Figure 5.12) related to the lower amount of Y and Yb, favor shallow lithospheric source for the Southwestern Cappadocia Volcanism.

18. ES volcanics present a clear Sr isotope negative trend while Nd ratios are in slightly increasing (Figure 5.14). The samples are plotted in the mantle area.

DISCUSSION and CONCLUSION

In previous chapters, volcanic rocks from Erciyes and Hasandağ stratovolcanoes, Obruk-Zengen and Karapınar dispersed volcanism were presented with inter and intra-group comparisons. Whereas, in this chapter the spatio-temporal evolution of the Quaternary basaltic volcanism in Central Anatolia have been discussed, using geological, geochronological, mineralogical, petrographical and geochemical results.

Erciyes stratovolcano

In the Sr-Nd isotope correlation diagram (Figure 5.14), Erciyes stratovolcano data plots within both the enriched and depleted mantle areas. As mentioned previously, these results are similar to those obtained in the Kerguelen area with an OIB-EMI source [START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF] and in the Society Islands area with an OIB-EMII source [START_REF] Devey | Active submarine volcanism on the Society hotspot swell (west pacific): A geochemical study[END_REF]. 206 Pb/ 204 Pb vs. 207 Pb/ 204 Pb isotope correlation diagram (Figure 5.17) reveals that Erciyes samples are related to an enriched mantle source such as EMII. EMI and EMII fields are defined as mantle fields enriched with the addition of sediments, continental crust and altered oceanic crust [START_REF] Rollinson | Using Geochemical Data: Evaluation, Presentation, Interpretation[END_REF][START_REF] Zindler | Chemical Geodynamics[END_REF].

The geochemical analysis given in Chapter 5 was used to characterize this enriched mantle source. Asthenospheric mantle Sr isotopic ratios (0.7022-0.7028), La/Nb (~0.7), Nb/La>1.3 [START_REF] Haase | Magmatism during extension of the lithosphere: geochemical constraints from lavas of the Shaban Deep, northern Red Sea[END_REF] and ε Nd (+8) values (De Paolo and Daley, 2000) are (0.703609-0.705084), (1.52-2.73), (0.47-0.66) and (+0.70-+5.05) respectively for Erciyes stratovolcano. High Nb/La (~>1) [154] and Nb/U (~47) [155] values are one of the typical characteristics of rocks that evolved from an OIB-like asthenospheric mantle source and were not exposed to crustal contamination.

Nb/La values of Erciyes stratovolcano samples were in the range of (0.51-0.66), (0.47-0.65) respectively for LDDS and MDDS, while Nb/U values were in the range of (10.64-23.34), (6.57-15.12), respectively.

Zr/Ba ratio is a parameter used to distinguish lithospheric sources (Zr/Ba: 0.3-0.5) from asthenospheric sources (Zr/Ba >0.5) [START_REF] Menzies | Enriched and depleted source components for tholeiitic and alkaline lavas from Zuni-Bandera, New Mexico: Inferences about intraplate processes and stratified lithosphere[END_REF][START_REF] Kürkçüoğlu | Geochemistry and petrogenesis of basaltic rocks from the Develidag volcanic complex, Central Anatolia, Turkey[END_REF]. Zr/Ba ratio is (0.4-1.2) for LDDS and (0.4-0.7) for MDDS at Erciyes.

Multi element diagrams (Figure 5.6) reveal no negative anomaly in the HFS elements Y and Yb. This demonstrates that the garnet phase that contains these elements during partial melting and related to a deep source was not effective.

According to [START_REF] Jung | Petrogenesis of Tertiary Mafic Alkaline Magmas in the Hocheifel, Germany[END_REF] Dy/Yb ratio that is greater than 2 is an indicator of residual garnet phase. Dy/Yb ratio is between (1.66-1.73) for differentiated samples and (1.73-1.86) for other samples. All samples have Dy/Yb ratios that are less than 2, which show the garnet phase was not highly effective. In light of the geochemistry data, it is considered that the Erciyes source of basalts s.l. is mainly lithospheric and/or associated to a minor interaction with a deeper source.

Partial Melting

Erciyes volcanics generally have high LILE and LREE content but low HFSE and HREE content (Figure 5.6 and Figure 5.7). This is related to magmatic differentiation processes (subduction, crustal contamination, etc.) or shows LILEs and LREEs tendency to shift into liquid phase during partial melting. Higher or lower LREE/HREE ratio is informative of the melting degree of the source. As a result of partial melting at low degrees, low Zr/Nb, Zr/Ba and high Th/Y, Ta/Th and La/Nb ratios should be observed (Table 5.3), whereas high Zr/Nb, Th/Y; low Zr/Ba, Ta/Th; and relatively high La/Nb ratios are observed in Erciyes volcanic rocks.

Magma is a result of partial melting taking place in the mantle or any solid source due to factors such as an adiabatic decompression, increase in environmental temperature and addition of volatile components. Basalt genesis generally occurs as a result of the partial melting of mantle sources [START_REF] Wilson | Igneous Petrogenesis[END_REF]. Due to the lack of data in Central Anatolian mantle xenoliths in the literature, the values for spinel peridotite [START_REF] Mcdonough | Constraints on the composition of the continental lithospheric mantle[END_REF] and garnet peridotite [START_REF] Frey | The origin of pyroxenites and garnet pyroxenites from Salt Lake Creater, Oahu, Hawaii: trace element evidence[END_REF] that reflect the composition of the upper mantle, were used. A source with spinel peridotite mineralogy is stated at shallow depth and exhibits lithospheric characteristics [START_REF] Wilson | Igneous Petrogenesis[END_REF][START_REF] Mcdonough | Constraints on the composition of the continental lithospheric mantle[END_REF][START_REF] Stern | Evidence from mantle xenoliths for relatively thin 100 km continental lithosphere below the Phanerozoic crust of southernmost South America[END_REF] therefore, a source with garnet peridotite mineralogy indicated a deeper source. The modal mineralogical composition of garnet peridotite is 60% olivine, 21% orthopyroxene, 8% clinopyroxene and 11% garnet whereas that of spinel peridotite is 58% olivine, 27% orthopyroxene, 8% clinopyroxene and 3% spinel [START_REF] Mckenzie | Partial melt distributions from inversion of rare Earth element concentrations[END_REF].

Modal bulk/equilibrium melting of any solid rock is a process where the liquid phase formed during partial melting of source rock reaches equilibrium by reacting continuously with the other solid phase until it begins to rise diapirically, and rises from the magma source, due to the difference in density only after the amount of melt reaches a certain quantity.

This type of partial melting is called modal bulk/equilibrium melting [START_REF] Wood | Elementary thermodynamics for geologists[END_REF][START_REF] Wilson | Igneous Petrogenesis[END_REF]. The equation used in modal bulk/equilibrium melting modeling is as follows: 1) Yb vs. La (Figure 6.1) bulk melting modeling [START_REF] Shaw | Trace element fractionation during anatexis[END_REF] was conducted using spinel and garnet peridotite as starting components. In the modeling, basalt samples were used to ensure accurate identification of the source. Values were corrected to MgO using fractionation correction to decrease the effects of fractional crystallization. Most of the basalt samples had 6-15% partial melting degrees similar to that of spinel peridotite between the spinel-garnet peridotite curves. ER13, the oldest and most alkaline of LDDS group, was close to the garnet peridotite curve with a partial melting degree of 8-10%. MREE/HREE ratios (Dy/Yb) are informative of garnet and spinel peridotite sources. Blundy et al.

 C L / C O  1 /  D o  F ( 1-D o )  (Equation
 C L =Concentration
(1998) stated melts where (Dy/Yb)N <1.06 had evolved from spinel peridotite sources. This ratio is between LDDS (1.17-1.26), MDDS (1.17-1.24) in Erciyes samples.

A modal batch partial melting modeling was conducted with trace element concentrations of spinel peridotite and ES samples. Calculated values obtained from modeling were normalized to Chondrite [START_REF] Sun | Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes[END_REF]) and the multiple element diagram given in Figure 6.2 was plotted. This diagram shows that the samples were formed through partial melting of the spinel peridotite source within the range F=5-15%. Figure 6.2 indicates that spinel peridotite was less effective in the formation of ER13 in comparison to the rest of the samples.

Partial melting modeling results with garnet peridotite as the starting component were not realistic. In the light of geochemistry results, it is considered that Erciyes stratovolcano samples partially melted at various degrees and, as (Dy/Yb)N>1.06 in all samples, garnet peridotite was also effective on the source as well as spinel peridotite.

Fractional Crystallization

When fractional crystallization is an effective process, olivine, pyroxene, Caplagioclase and oxides are the first components to separate from the cooling melt.

The composition of the remaining melt and the composition of the crystals forming from this melt will differ in composition with respect to their stages of generation of magma. Therefore, many values in the melt will vary as long as fractional crystallization continues (i.e. SiO 2 will increase and Mg# will decrease) which allows us to explain the origin of rocks with various compositions forming from a single magmatic source. Modeling studies are carried out to reveal how this process affects rock formation. Fractional crystallization (FC) modeling can be applied when a phase is removed from a homogeneous medium with chemical or isotropic fractionation [START_REF] Albaréde | Introduction to Geochemical Modelling[END_REF].

FC modeling is mainly concerned with trace element fractionation in solidifying magma together with hydrothermal processes or for example, the evaporation of lakes. In this case, while primary magma composition changes with fractionation, mineral phases removed from the environment with fractionation and will have different compositions than parent melt and will be spatially zoned, due to the change in magma composition. 2) -1) (equation for the enrichment of а trace element relative to the original liquid) (Equation 3) -1) (equation for the mеаn enrichment of а trace element in the cumulate) (Equation 4)

 C R / C o =D o F ( Do
 C R / C o =(1-F) ( Do
C R= Concentration of element (i) in any solid that crystallizes in the magma and is spontaneously removed from the melt (settles with gravitative processes). Other abbreviations are explained in the previous section. Clinopyroxene fractionation is more apparent especially in MDDS (Figure 6.3).

Furthermore, the scattered distribution of some elements in Harker variation diagrams demonstrates that fractional crystallization was not the only effective process (Verma, 1999). As mentioned previously in Chapter 5, the trends in the variation diagrams reveal olivine, plagioclase and pyroxene fractionation.

FC modeling elicited more detailed information on the process. [START_REF] Class | Geochemistry of Pliocene to Quaternary alkali basalts from the Huri Hills, northern Kenya[END_REF][START_REF] Polat | Geochemistry of Qaternary basalts erupted along the east Anatolian and Dead Sea Fault zones of southern Turkey: implications fro mantle sources[END_REF]Ormerod et al., 1988;[START_REF] Downes | Petrology and geochemistry of late Tertiary/Quaternary mafic alkaline volcanism in Romania[END_REF][START_REF] Kürkçüoğlu | Geochemical approach to magmatic evolution of Mt.Erciyes stratovolcano Central Anatolia, Turkey[END_REF][START_REF] Kürkçüoğlu | Trace Element Modelling and Source Constraints for Tholeiitic and Calc-Alkaline Basalts from a Depleted Asthenospheric Mantle Source, Mt. Erciyes Stratovolcano, Turkey[END_REF][START_REF] Cebria | Geochemistry of the Quaternary alkali basalts of Garrotxa (NE Volcanic Province, Spain): a case of double enrichment of the mantle lithosphere[END_REF][START_REF] Ma | Petrogenesis of Latest Miocene-Quaternary Continental Intraplate Volcanism along the Northern Dead Sea Fault System (Al Ghab-Homs Volcanic Field), Western Syria: Evidence for Lithosphere-Astnenosphere Interaction[END_REF]Çubukcu, 2008;[START_REF] Özdemir | Volcanostratigraphy and Petrogenesis of Süphan Stratovolcano[END_REF][START_REF] Ali | Alkali basalts from Burgenland, Austria: Petrological constraints on the origin of the westernmost magmatism in the Carpathian-Pannonian Region[END_REF][START_REF] Alıcı | Quaternary tholeiitic to alkaline volcanism in the Karasu Valley, Dead Sea Rift Zone, southeast Turkey: Sr-Nd-Pb-O isotopic and trace-element approaches to crust-mantle interaction[END_REF][START_REF] Alıcı Şen | Anadoluda'ki Kuvaterner Yaşlı Bazaltik Vokaniklerin Kökeni[END_REF][START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF][START_REF] Tang | Asthenoshere-litospheric mantle interaction in an extensional regime: Implication from the geochemistry of Cenozoic basalts from Taihang Mountains, North China Craton[END_REF] Özdemir ( 2011) reported both lithospheric and asthenospheric mantles were effective in the genesis of lavas from Süphan stratovolcano and other Eastern Anatolian volcanics (Ağrı, Nemrut, Tendürek) and that lithospheric mantle effect increased from Miocene-Pliocene to Quaternary. Özdemir (2011) suggested that the asthenospheric upwelling and widespread volcanism in the area could be due to both slab break off and partial loss of lower lithosphere.

In Figure 6.4b, Quaternary Erciyes stratovolcano samples were compared to [START_REF] Kürkçüoğlu | Geochemical approach to magmatic evolution of Mt.Erciyes stratovolcano Central Anatolia, Turkey[END_REF]2001) and [START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF] samples with no radiometric dating. All of the samples in the present study are mostly (Figure 2.7) calcalkaline rocks of Erciyes s.s. (Figure 5.1) whereas [START_REF] Kürkçüoğlu | Geochemical approach to magmatic evolution of Mt.Erciyes stratovolcano Central Anatolia, Turkey[END_REF]2001) and [START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF] samples mostly consist of Koçdağ and Erciyes calcalkaline basalts and basaltic andesites. Nb and Th are relatively immobile in aqueous fluids [START_REF] Brenan | Mineralaqueous fluid partitioning of trace elements at 900 oC and 2.0 Gpa: constraints on the trace element chemistry of mantle and deep crustal fluids[END_REF][START_REF] Elliot | Element transport from slab to volcanic front at the Mariana arc[END_REF]. While Th/Y ratio directly is proportional to increasing Nb/Y ratio, suggesting a within plate enrichment, Th/Y increasing in contrast to low Nb/Y is an indicator of subduction enrichment.

In Erciyes samples, both Nb/Y increasing in direct proportion to Th/Y and Th/Y increasing in contrast to Nb/Y is observed (Figure 6.6a).

Comparative data sources given in Figure 6.6a shows that Ceyhan -Osmaniye, Karasu Valley, Huri Hills and Garrotxa basalts reported to have asthenospheric mantle sources all plotted in OIB area. As mentioned previously, although

Romanian Persani alkali basalts have a strong asthenospheric mantle source, there are traces of an earlier subduction [START_REF] Downes | Petrology and geochemistry of late Tertiary/Quaternary mafic alkaline volcanism in Romania[END_REF]. [START_REF] Class | Geochemistry of Pliocene to Quaternary alkali basalts from the Huri Hills, northern Kenya[END_REF][START_REF] Polat | Geochemistry of Qaternary basalts erupted along the east Anatolian and Dead Sea Fault zones of southern Turkey: implications fro mantle sources[END_REF]Ormerod et al., 1988;[START_REF] Downes | Petrology and geochemistry of late Tertiary/Quaternary mafic alkaline volcanism in Romania[END_REF][START_REF] Kürkçüoğlu | Geochemical approach to magmatic evolution of Mt.Erciyes stratovolcano Central Anatolia, Turkey[END_REF][START_REF] Kürkçüoğlu | Trace Element Modelling and Source Constraints for Tholeiitic and Calc-Alkaline Basalts from a Depleted Asthenospheric Mantle Source, Mt. Erciyes Stratovolcano, Turkey[END_REF][START_REF] Cebria | Geochemistry of the Quaternary alkali basalts of Garrotxa (NE Volcanic Province, Spain): a case of double enrichment of the mantle lithosphere[END_REF][START_REF] Ma | Petrogenesis of Latest Miocene-Quaternary Continental Intraplate Volcanism along the Northern Dead Sea Fault System (Al Ghab-Homs Volcanic Field), Western Syria: Evidence for Lithosphere-Astnenosphere Interaction[END_REF]Çubukcu, 2008;[START_REF] Özdemir | Volcanostratigraphy and Petrogenesis of Süphan Stratovolcano[END_REF][START_REF] Ali | Alkali basalts from Burgenland, Austria: Petrological constraints on the origin of the westernmost magmatism in the Carpathian-Pannonian Region[END_REF][START_REF] Alıcı | Quaternary tholeiitic to alkaline volcanism in the Karasu Valley, Dead Sea Rift Zone, southeast Turkey: Sr-Nd-Pb-O isotopic and trace-element approaches to crust-mantle interaction[END_REF][START_REF] Alıcı Şen | Anadoluda'ki Kuvaterner Yaşlı Bazaltik Vokaniklerin Kökeni[END_REF][START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF][START_REF] Tang | Asthenoshere-litospheric mantle interaction in an extensional regime: Implication from the geochemistry of Cenozoic basalts from Taihang Mountains, North China Craton[END_REF] According to [START_REF] Fitton | The role of lithospheric mantle in the generation of Late Cenezoic basic magmas in the Western United States[END_REF], Ba/Nb >28 is a typical arc magmatism characteristic. This ratio (Ba/Nb >28) ranges between LDDS (18-22) and MDDS (22-28) (Table 5.3). High Ba/Ta (>450) ratio, which is also typical for arc magmatism, is between LDDS (220-411) and . A low La/Nb ratio is indicative of within-plate enrichment [START_REF] Huang | Geochemistry of late Cenozoic basaltic volcanism in Northland and Coromandel, New Zealand: implications for mantle enrichment processes[END_REF] or an asthenospheric source (De Paolo and Daley, 2000) whereas a high La/Nb ratio is indicative of subduction enrichment [START_REF] Huang | Geochemistry of late Cenozoic basaltic volcanism in Northland and Coromandel, New Zealand: implications for mantle enrichment processes[END_REF] or a lithospheric source (>1) (De Paolo and Daley, 2000). [START_REF] Hart | Basaltic volcanism in Ethiophia: constraints on continental rifting and mantle interractions[END_REF] suggested that La/Ta should be greater than 22 and La/Nb should be greater than 1.5 in rocks affected by crustal contamination. La/Ta and La/Nb ratios range between 19.71-32.67 and 1.52-2.73, respectively. Furthermore, Nb-Ta-Ti negative and Pb positive anomalies observed in both groups in Figure 5. Lower Pliocene sedimentary rocks (intercalated carbonate sandstones, semimetamorphosed limestones, sandy and argillaceous marls and gypsum-bearing sediments) (Ayrancı,1991). Due to the small number of isotope and dating analyses of primary rocks in the literature, potential contaminants were selected through a detailed research. The contaminants selected accordingly were i) biotitemoscovite granite found in Agaçören Igneous Association [START_REF] Köksal | Crustal homogenization revealed by U-Pb zircon ages and Hf isotope evidence from the Late Creataceous granitoids of the Ağaçören intrusive suite (Cental Anatolia/Turkey)[END_REF] ii) monzonite from subalkaline-transitional Barandağ granitoid (İlbeyli, 2004) found in Central Anatolian Volcanic Province.

The change in composition after assimilation of wall rock and the occurrence of both assimilation and fractional crystallization during the solidification of magma can be identified with AFC modeling. For this purpose, the equations developed by De Paolo (1981) for assimilation-fractional crystallization (AFC) modeling were used.

These equations revealing both trace element and isotropic effects of AFC modeling are given below:

AFC modeling for trace elements: 5)

C m / C o = f ' + (r / (r-1+D o )) * C a / C m o* ( 1-f ' ) (Equation
R= ratio of assimilation rate to fractionation rate CIPW norms of C88-79 (55.69% plagioclase, 19.58 % clinopyroxene, 16.06% olivine, 2.81% nepheline, 2.6% ilmenite, 1.06% K-feldspar, 0.12% magnetite) used as end member were obtained from [START_REF] Kürkçüoğlu | Erciyes stratovolkanı'nın Jeokimyasal Evrimi, Doktora Tezi[END_REF]. Mineral/melt partition coefficients (Kd) for basaltic melts were calculated from [START_REF] Fujimaki | Partition coefficients of Hf, Zr, and REE between phenocrysts and groundmasses[END_REF], [START_REF] Mckenzie | Partial melt distributions from inversion of rare Earth element concentrations[END_REF], [START_REF] Rollinson | Using Geochemical Data: Evaluation, Presentation, Interpretation[END_REF] and (www.earthref.org/KDD/). Rvalues representing the ratio of assimilation rate to fractionation rate given in Equation 6were determined as illustrated in Figure 6.7 (a-b). Figure 6. 7 (a-b) shows that the samples were exposed to crustal contamination within the range of 0.1-0.3 (Figure 6.7a) and 0.2-0.5 (Figure 6.7b) except for ER13, which differs from the rest of the samples.

Mixing Sources

The occurrence of both plagioclases, in equilibrium and out of equilibrium, in the same sample allows us to consider that the genesis conditions were not homogeneous. Besides, the association of both equilibrium and disequilibrium olivines were observed. Temperature (Table 4. Accordingly, all Erciyes samples plot on the mixing curve. [START_REF] Zindler | Chemical Geodynamics[END_REF], NMORB [START_REF] Okamura | Cenozoic magmatism of the north-eastern Eurasian margin: the role of lithosphere versus asthenosphere[END_REF], FOZO [START_REF] Hart | Mantle plumes and entrainment: isotopic evidence[END_REF], Tibet [START_REF] Tang | Asthenoshere-litospheric mantle interaction in an extensional regime: Implication from the geochemistry of Cenozoic basalts from Taihang Mountains, North China Craton[END_REF], Süphan stratovolcano (Özdemir et al., 2011), Society [START_REF] Devey | Active submarine volcanism on the Society hotspot swell (west pacific): A geochemical study[END_REF], Kula [START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF], Basin and Range [START_REF] Kempton | Isotopic and trace element constrains on the composition and evolution of the lithosphere beneath the southwestern United States[END_REF], Kergeluen [START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF].

In the diagram (Figure 6.8), as in Figure 6.4a and 6.6a, Erciyes volcanics, except for ER13, display similar trends to Süphan stratovolcano samples with a lithospheric + asthenospheric mantle interaction where the lithospheric mantle effect increases as the samples get younger, and Society Islands samples with an enriched mantle source such as EMII. Whereas, ER13 is similar to an asthenospheric mantle source such as Basin and Range [START_REF] Kempton | Isotopic and trace element constrains on the composition and evolution of the lithosphere beneath the southwestern United States[END_REF] where it is not affected by crustal contamination, and Kula volcanics [START_REF] Alıcı Şen | Anadoluda'ki Kuvaterner Yaşlı Bazaltik Vokaniklerin Kökeni[END_REF] postulated to have mostly asthenospheric and limited contribution of a lithospheric mantle component source.

Southwestern Cappadocia Volcanism

Multi element diagrams of the samples found in Hasandağ stratovolcano (HS) (Figure 5.12a), Obruk-Zengen (OZ) (Figure 5.12b) and Karapınar (K) dispersed volcanism (Figure 5.12c) display a nearly similar pattern. On the other hand, a strongly negative anomaly for Nb-Ta and Ti, as well as, a positive anomaly for incompatible elements such as Th, U and particularly Pb is observed gradually from northeast to southwest in HS, OZ and K; respectively. This indicates effects of subduction or crustal contamination [START_REF] Downes | Petrology and geochemistry of late Tertiary/Quaternary mafic alkaline volcanism in Romania[END_REF]. In the Sr-Nd correlation diagram (Figure 5.25), all the samples plotted in the mantle array and, therefore, have mantle sources, whereas particularly OZ samples plotted in the depleted mantle array and some HS and K samples plotted in the enriched mantle array. As mentioned previously, these samples are similar to the Kerguelen lavas with OIB-EMI source [START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF] and Society Islands lavas with OIB-EMII source [START_REF] Devey | Active submarine volcanism on the Society hotspot swell (west pacific): A geochemical study[END_REF]. 206 Pb/ 204 Pb vs. 207 Pb/ 204 Pb isotope diagram (Figure 5.28) reveals that OZ and HS values are similar to an enriched mantle source such as EMII, while K samples have values more similar to an area between EMII and upper crust. EMI and EMII fields are defined as mantle fields enriched with the addition of constituents such as sediments, continental crust, and altered oceanic crust into the mantle [START_REF] Rollinson | Using Geochemical Data: Evaluation, Presentation, Interpretation[END_REF][START_REF] Zindler | Chemical Geodynamics[END_REF].

The chemical composition of the samples was used in the determination of the characteristics of this enriched mantle source. Asthenospheric mantle Sr isotope (0.7022-0.7028), La/Nb (~0.7) and εNd (+8) values (De Paolo and Daley, 2000) are respectively (0.704625-0.704976), (1.72-2.22), (0.38-1.57) for HS, (0.704153-0.704711), (1.63-2.33), (1.67-3.67) for OZ and (0.705188-0.705502), (2.63-3.53), (-0.18 --0.69) for K. As mentioned previously, high Nb/La (~>1) (Abdel-Rahman and Lease, 2012) and Nb/U(~47) [START_REF] Hofmann | Mantle geochemistry:the mesaage from oceanic volcanism[END_REF] values are typical characteristics of rocks that evolved from an OIB-like asthenospheric mantle source and were not exposed to crustal contamination. Nb/La varies between (0.45-0.58), (0.43-0.61), (0.28-0.38) while Nb/U varies (12.43-21.01), (5.83-18.15), (4.08-8.86) for HS, OZ and K respectively. Zr/Ba ratio ranges between (0.38-0.51) for HS, (0.38-0.65) for OZ and (0.32-0.41) for K. In light of the geochemical data, it is considered that Southwestern Cappadocia volcanism was affected mainly by the lithospheric mantle but, in addition, could have interacted with a deeper asthenospheric source.

Partial Melting

Yb vs. La bulk melting modeling [START_REF] Shaw | Trace element fractionation during anatexis[END_REF] was conducted using spinel and garnet peridotite as starting components (Figure 6.9). As SiO 2 (49-52%), MgO (7-11%), Cr (288-346 ppm) and Ni (128-177ppm) for the samples whose data sets were used in the diagram, the values were not fractionation-corrected. According to the diagram, HS (%8-9), OZ (%8-12) and K (%8) have varying partial melting degrees. Most of Southwestern Cappadocia samples were close to spinel peridotite curve, which is related to a lithospheric source, whereas some samples plotted between garnet and spinel peridotite curves.

Multi element diagrams (Figure 5.12) reveal no negative anomaly in the HFS elements as Y and Yb, which indicates that garnet phase containing these elements during partial melting had a limited effect. According to [START_REF] Jung | Petrogenesis of Tertiary Mafic Alkaline Magmas in the Hocheifel, Germany[END_REF], a Dy/Yb ratio greater than 2 is another criterion for residual garnet phase.

Dy/Yb ratios ranging between respectively (1.74-1.84), (1.71-1.93) and (1.70-1.73) for HS, OZ and K support the information given above. In order to test the values given above, a modal bulk/equilibrium (batch) melting modeling normalized to Chondrite [START_REF] Sun | Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes[END_REF]) was conducted (Figure 6.10).

The modeling revealed that HS (Figure 6.10a) and K (Figure 6.10c) magmas are related to the partial melting of spinel peridotite source at F=5-10% interval whereas OZ (Figure 6.10b) was formed by the partial melting of the same source at F=5-15% interval. According to the modeling results (Table 6.4), OZ samples exhibited very little or even none plagioclase fractionation whereas clinopyroxene and olivine fractionation was observed (Figure 6.11). HA31 from HS group, HA27 from OZ group and KA19 LREEs to shift into liquid phase during partial melting. Furthermore, high LREE/HREE ratio suggests that the magma was derived from an enriched mantle source or as a result of a low degree partial melting.

Fractional Crystallization

As related in Section 6.1.3, ratios of incompatible elements such as Th, Ta and Yb will not change during partial melting and fractional crystallization. In Th/Yb vs.

Ta/Yb diagram, OZ displays mainly crustal contamination enrichment whereas K displays both crustal contamination and subduction enrichment. HS does not exhibit a significant trend (Figure 6.12). [START_REF] Class | Geochemistry of Pliocene to Quaternary alkali basalts from the Huri Hills, northern Kenya[END_REF][START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF][START_REF] Polat | Geochemistry of Qaternary basalts erupted along the east Anatolian and Dead Sea Fault zones of southern Turkey: implications fro mantle sources[END_REF]Ormerod et al., 1988;[START_REF] Downes | Petrology and geochemistry of late Tertiary/Quaternary mafic alkaline volcanism in Romania[END_REF][START_REF] Kürkçüoğlu | Geochemical approach to magmatic evolution of Mt.Erciyes stratovolcano Central Anatolia, Turkey[END_REF]2001;[START_REF] Cebria | Geochemistry of the Quaternary alkali basalts of Garrotxa (NE Volcanic Province, Spain): a case of double enrichment of the mantle lithosphere[END_REF][START_REF] Ma | Petrogenesis of Latest Miocene-Quaternary Continental Intraplate Volcanism along the Northern Dead Sea Fault System (Al Ghab-Homs Volcanic Field), Western Syria: Evidence for Lithosphere-Astnenosphere Interaction[END_REF]Çubukcu, 2008;[START_REF] Özdemir | Volcanostratigraphy and Petrogenesis of Süphan Stratovolcano[END_REF][START_REF] Ali | Alkali basalts from Burgenland, Austria: Petrological constraints on the origin of the westernmost magmatism in the Carpathian-Pannonian Region[END_REF][START_REF] Alıcı | Quaternary tholeiitic to alkaline volcanism in the Karasu Valley, Dead Sea Rift Zone, southeast Turkey: Sr-Nd-Pb-O isotopic and trace-element approaches to crust-mantle interaction[END_REF][START_REF] Alıcı Şen | Anadoluda'ki Kuvaterner Yaşlı Bazaltik Vokaniklerin Kökeni[END_REF][START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF][START_REF] Tang | Asthenoshere-litospheric mantle interaction in an extensional regime: Implication from the geochemistry of Cenozoic basalts from Taihang Mountains, North China Craton[END_REF].

HS, OZ and K volcanics from

HS and OZ that plotted similarly to Eastern Anatolian volcanics may be considered to be related to both lithospheric and asthenospheric mantle sources (Figure 6.12a). While isotope (Sr-Nd-Pb and O) data, trace element ratios and єNd values confirmed that lithospheric mantle was more effective, temporal evaluation of lithospheric mantle interaction could not be demonstrated.

Quaternary Southwestern Cappadocia samples of the present study were compared to other samples without radiometric dating collected from the same volcanic area [START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF][START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF]. All of Southwestern Cappadocia volcanics were neovolcanic (Figure 2.8) and most consisted of alkali rocks (Figure 5.10). HS, OZ and K samples of the present study have similar trends with samples of previous researchers [START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF][START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF]) (Figure 6.12b). More significant subduction-related enrichment and/or crustal contamination trends in K than in HS and OZ. This trend is also observed in multiple element diagrams in Figure 5.14.

HS, OZ and K have different trends in 87 Sr/ 86 Sr vs. SiO 2 and Rb/Sr diagrams (Figure 6.13). K was more related to crustal contamination than HS and OZ, and fractional crystallization was more effective in HS (Figure 6.13).

In Th/Y vs. Nb/Y diagram (Figure 6.14), all Southwestern Cappadocia data range between Th/Nb = 0.1 and Th/ Nb = 1. Nb/Y and Th/Y ratios are tracers that can be used for the determination of source heterogeneity and crustal contamination effects [START_REF] Pearce | The role of the sub-contiental lithosphere in magma genesis at active continental margins[END_REF] while Th/Nb ratio is a good tracer for arc lavas [START_REF] Brenan | Mineralaqueous fluid partitioning of trace elements at 900 oC and 2.0 Gpa: constraints on the trace element chemistry of mantle and deep crustal fluids[END_REF][START_REF] Elliot | Element transport from slab to volcanic front at the Mariana arc[END_REF] Cappadocia volcanics to the samples of previous researchers could not be carried out in Figure 6.14 due to the lack of some trace element data. High Ba/Nb (>28) and Ba/Ta (˃450) ratios are typical for subducted-related magma [START_REF] Fitton | The role of lithospheric mantle in the generation of Late Cenezoic basic magmas in the Western United States[END_REF]Gill,1981) for HS, OZ and K and are respectively (22-28; 20-36; 32-44) and (283-395; 273-462; 573-664). A low La/Nb ratio is indicative of within-plate enrichment [START_REF] Huang | Geochemistry of late Cenozoic basaltic volcanism in Northland and Coromandel, New Zealand: implications for mantle enrichment processes[END_REF] or an asthenospheric source (De Paolo and Daley, 2000) whereas a high La/Nb ratio is indicative of subduction enrichment [START_REF] Huang | Geochemistry of late Cenozoic basaltic volcanism in Northland and Coromandel, New Zealand: implications for mantle enrichment processes[END_REF] or a lithospheric source (>1) (De Paolo and Daley, 2000). Ormerod et al., 1988;[START_REF] Morris | Subduction style magmatism in a Non-subduction setting: The Colville Igneous Complex, NE Washington State,USA[END_REF][START_REF] Çubukçu | Nemrut Stratovolkanının petrolojik Evrimi: Çarpışma Bölgesinde Peralkali Magmatizma[END_REF]Parker, D.F et al., 2010;[START_REF] Özdemir | Volcanostratigraphy and Petrogenesis of Süphan Stratovolcano[END_REF][START_REF] Alıcı Şen | Anadoluda'ki Kuvaterner Yaşlı Bazaltik Vokaniklerin Kökeni[END_REF][START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF][START_REF] Tang | Asthenoshere-litospheric mantle interaction in an extensional regime: Implication from the geochemistry of Cenozoic basalts from Taihang Mountains, North China Craton[END_REF] Trace element ratios in rocks affected by crustal contamination are La/Ta>22 and La/Nb>1.5 [START_REF] Hart | Basaltic volcanism in Ethiophia: constraints on continental rifting and mantle interractions[END_REF]. Accordingly, HS, OZ and K La/Nb ratios range between (1. 72-2.22; 1.63-2.33; 2.63-3.53) and La/Ta ratios range between (23-32; 24-44; 46-58); respectively. All trace element ratios given above gradually increase from HS in the north to K in the southwest. In Figure 5.12, Nb-Ta-Ti negative anomaly and Pb positive anomaly increase gradually from HS (Figure 5.12a) to OZ (Figure 5.12b) and K (Figure 5.12c), thus, supporting the data presented above. This demonstrates that the groups were affected by crustal contamination and/or subduction-related enrichment at different degrees.

Potential Contaminants and AFC Modeling

Using AFC modeling and the equations explained in Section 6.1.3.1, isotope AFC modeling was conducted for HS, OZ and K areas. Samples with highest alkalinity in three groups (HA23b, HA26 and KA19) were selected as end members and the same contaminants used for Erciyes stratovolcano AFC modeling, namely biotitemoscovite granite (bmg-1) [START_REF] Köksal | Crustal homogenization revealed by U-Pb zircon ages and Hf isotope evidence from the Late Creataceous granitoids of the Ağaçören intrusive suite (Cental Anatolia/Turkey)[END_REF] and plutonic (monzonite) N-26 (İlbeyli, 2004) were employed as contaminants.

CIPW norms of end member samples are given in Table 5. [START_REF] Zindler | Chemical Geodynamics[END_REF], NMORB [START_REF] Okamura | Cenozoic magmatism of the north-eastern Eurasian margin: the role of lithosphere versus asthenosphere[END_REF], FOZO [START_REF] Hart | Mantle plumes and entrainment: isotopic evidence[END_REF], ,Tibet [START_REF] Tang | Asthenoshere-litospheric mantle interaction in an extensional regime: Implication from the geochemistry of Cenozoic basalts from Taihang Mountains, North China Craton[END_REF], Süphan stratovolcano (Özdemir et al.,2011), Society [START_REF] Devey | Active submarine volcanism on the Society hotspot swell (west pacific): A geochemical study[END_REF], Kula [START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF], Basin and Range [START_REF] Kempton | Isotopic and trace element constrains on the composition and evolution of the lithosphere beneath the southwestern United States[END_REF], Kergeluen [START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF] Multi element diagrams (Figure 5.12), Sr-Nd isotope correlation diagram (Figure 5.25) and Pb isotope correlation diagram (Figure 5.28) of Southwestern Cappadocia volcanics suggest that, similarly to ES, these volcanics also evolved from an enriched heterogeneous source. Mixing modeling of the sources named FOZO [START_REF] Hofmann | Mantle geochemistry:the mesaage from oceanic volcanism[END_REF] and/or C (Hannan and Graham,1996), explained in detail in Section 6.1.4, and EMII source was conducted (Figure 6.16). In the diagram, all HS and OZ samples plotted on the mixing curve whereas K samples plotted near to the mixing curve. In Figure 6.16, HS, OZ and K samples plotted similarly to Süphan stratovolcano samples with a lithospheric + asthenospheric mantle mixture (Özdemir, 2011) and Society Islands samples with an enriched mantle source such as EMII.

Tectonics

Turkey is a part of the Alpine-Himalayan orogenic belt and one of the most active and complex zones in the world. In order to understand tectonics in Turkey and its structural elements, the Mediterranean Region, especially the Eastern Mediterranean Region, should be examined [START_REF] Bozkurt | Neotectonics of Turkey-a synthesis[END_REF][START_REF] Faccenna | Subduction and the depth of convection in the Mediterranean mantle[END_REF][START_REF] Faccenna | Slab detachment beneath eastern Anatolia: A posible cause for the formation of the Noth Anatolian fault[END_REF][START_REF] Biryol | Segmented African lithosphere beneath the Anatolian region inferred from teleseismic P-wave tomography[END_REF].

The collision of the Eurasian-Arabian plates in the Middle (Early) Miocene changed the Anatolian tectonic regime and initiated the neotectonic period [START_REF] Şengör | Türkiyenin Neotektoniğinin Esasları[END_REF][START_REF] Şengör | Tethyan evolution of Turkey: a plate tectonic approach[END_REF]. This continental collision caused N-S compression in Eastern Anatolia and deformations in the continental crust along the Bitlis Suture Zone. The continental crust shortening and thickening in time, failing to correspond the deformations, enabled the formation of two important transform faults and the Anatolian Block. These are the dextral North Anatolian Fault Zone (NAFZ) and the sinistral East Anatolian Fault Zone (EAFZ).

The development of within plate deformations related to i) collision and ii) subduction roll-back along the Aegean Subduction Zone in the Anatolian Block that lies approximately between NAFZ and EAFZ has been argued [START_REF] Faccenna | Slab detachment beneath eastern Anatolia: A posible cause for the formation of the Noth Anatolian fault[END_REF][START_REF] Biryol | Segmented African lithosphere beneath the Anatolian region inferred from teleseismic P-wave tomography[END_REF]. Various researchers suggested that, due to the movement of the Arabian, African and Eurasian plates, the Anatolian Block escaping to the west was composed of microplates and that pull-apart basins and thrust faults developed as a result of the mentioned within-plate deformations (Mc Kenzie, 1972;[START_REF] Şengör | Türkiyenin Neotektoniğinin Esasları[END_REF][START_REF] Şengör | Strike slip faulting and related basin formation in zones of tectonic escape: Turkey as a case study, Strike-slip Deformation, Basin Formation and Sedimantation[END_REF][START_REF] Dewey | Shortening of continental lithosphere: The neotectonics of Eastern Anatolia, a young collision zone. Collisionc Tectonics[END_REF][START_REF] Lyberis | The East Anatolian Fault: an oblique collisional belt[END_REF]Yürür and Chorowicz,1998;[START_REF] Dhont | Emplacement of volcanic vents and geodynamics of Central Anatolia, Turkey[END_REF]. NAFZ is bounded by the Hellenic shear zone near the Gulf of Saros, which slowed its westward escape and caused a compression in the E-W direction. This compression is balanced with tension stress in the N-S direction and resulted in the development of E-W oriented graben-horst systems in the Western Anatolia Region [START_REF] Mckenzie | Active tectonics of the Mediterranean Region[END_REF]Dewey and Şengör, 1979).

Central Anatolia is bounded by Eastern Anatolia subject to the effect of compressional regime since Middle Miocene and Western Anatolia under the influence of tensional regime [START_REF] Yılmaz | Allochthonous terranes in the Tethyan Middle East: Anatolia and the surroundings regions[END_REF]. Various researchers have indicated that the formation of the Central Anatolian volcanism mostly occurred after the collision along the Bitlis Suture Zone [START_REF] Innocenti | The Neogene calc-alcaline volcanic of Central Anatolia: Geochronological data on Kayseri-Niğde area[END_REF][START_REF] Şengör | Türkiyenin Neotektoniğinin Esasları[END_REF], Pasquaré et al., 1988). Besides, the arc volcanism began 10-13 Ma ago and continued until historical times [START_REF] Innocenti | The Neogene calc-alcaline volcanic of Central Anatolia: Geochronological data on Kayseri-Niğde area[END_REF].

The Ecemiş Fault (EF), the Tuzgölü Fault (TF) and local faults are important structural elements of the Central Anatolian Volcanic Province that encompasses the study area. The study of these faults is significant to the association of tectonics and volcanism in the region.

Ecemiş Fault Zone (EFZ)

The Ecemiş Fault was thought to play a significant role in the development of the Erciyes stratovolcano and has been the focus of much research [START_REF] Arpat | Türkiye'deki bazı önemli genç tektonik olaylar[END_REF][START_REF] Yetiş | Ecemiş fay kuşağının jeo-tektonik evrimi[END_REF]Pasquaré, 1988;[START_REF] Toprak | Keçiboyduran-Melendiz fayı ve bölgesel anlamı (OrtaAnadolu)[END_REF][START_REF] Koçyiğit | A new intracontinental transcurrent structure : the Central Anatolian Fault Zone, Turkey[END_REF]. The Ecemiş Fault, denominated differently by various researchers (Bluementhal, 1941;[START_REF] Metz | Aladağ ve Karanfil dağının yapısı ve bunların Kilikya torusu tesmiye edilen batı kenarları hakkında malumat husulü için yapılan jeolojik etüd: MTA Enst[END_REF][START_REF] Yetiş | Ecemiş fay kuşağının jeo-tektonik evrimi[END_REF]Demirkol, 1984, Koçyiğit and[START_REF] Koçyiğit | A new intracontinental transcurrent structure : the Central Anatolian Fault Zone, Turkey[END_REF] was considered a part of the Central Anatolia Fault Zone (CAVZ) together with the other faults in the region and their segments. CAVZ was defined as a 700 km long, 280 km wide, NE-SW oriented, left-lateral strikeslip fault zone [START_REF] Koçyiğit | A new intracontinental transcurrent structure : the Central Anatolian Fault Zone, Turkey[END_REF]. The age of the Ecemiş fault was estimated as post-Paleocene and pre-Lutetian and it were suggested that EF was a left-lateral strike-slip fault in Quaternary times [START_REF] Yetiş | Ecemiş fay kuşağının jeo-tektonik evrimi[END_REF] Parallel segments and different types of related pull-apart basins have developed in the Ecemiş Fault Zone [START_REF] Şengör | Tethyan evolution of Turkey: a plate tectonic approach[END_REF][START_REF] Yetiş | Ecemiş fay kuşağının jeo-tektonik evrimi[END_REF]Pasquaré et al., 1988, Koçyiğit and[START_REF] Koçyiğit | A new intracontinental transcurrent structure : the Central Anatolian Fault Zone, Turkey[END_REF]. The most important of these pull-apart basins is Sultansazlığı [START_REF] Şengör | Tethyan evolution of Turkey: a plate tectonic approach[END_REF]Pasquaré et al., 1988). The Sultansazlığı pull-apart basin is an S-shaped depression basin that is approximately 35 km wide, 120 km long, and more than 1 km deep. The Erciyes stratovolcano is located at the NNW of Sultansazlığı pull-apart basin and at the center of the Erciyes pull-apart basin. Pasquaré et al. (1988) and [START_REF] Toprak | Keçiboyduran-Melendiz fayı ve bölgesel anlamı (OrtaAnadolu)[END_REF] reported to be the product of the latest activity of the fault [START_REF] Kürkçüoğlu | Erciyes stratovolkanı'nın Jeokimyasal Evrimi, Doktora Tezi[END_REF]. The calcalkaline basaltic andesite ER17 and the alkali basaltic trachyandesite ER29

recovered respectively 2 and 4km NW of Göğdağ in the present study were dated respectively as 45±7 ka and 13±5 ka (Figure 2.2). Moreover, the existence of the calcalkaline andesites ER9 (<1ka), and ER22 (40±7ka), as well as, the calcalkaline basaltic andesite ER11 (<1ka) and ER26 (25±8ka) indicate that northern and northwestern Erciyes was also an active region in historical times.

However, [START_REF] Kürkçüoğlu | Erciyes stratovolkanı'nın Jeokimyasal Evrimi, Doktora Tezi[END_REF] later suggested in a verbal correspondence with Dr.

Tekin Yürür, that the Ecemiş fault could be lithospheric and could have been responsible for the volcanism in the Erciyes stratovolcano. The coexistence of old, young, alkali and calcalkaline volcanic rocks along the Ecemiş fault and the other mentioned lines substantiates the idea that the faults in the region were active during the Quaternary Period and that it had a significant effect on regional volcanism. However, the last products are not only alkaline but also calcalkaline.

Possible Magma Sources

 Subduction Component

Positive anomalies in Ba, Th, Pb and negative anomalies in Nb-Ta-Ti are characteristics of subducting-related magma [START_REF] Fitton | The role of lithospheric mantle in the generation of Late Cenezoic basic magmas in the Western United States[END_REF][START_REF] Saunders | Transver geochemical variations across the Antartic Peninsula: implications for genesis of calkalkaline magmas[END_REF]. These anomalies are observed in Erciyes and Southwestern Cappadocia (HS, OZ and K) volcanics (Figure 5.6 and 5.12). However, this negative anomaly in Nb-Ta might also indicate crustal contamination of mantle derived magmas rising to the surface [START_REF] Wilson | Igneous Petrogenesis[END_REF]. Negative anomaly patterns in Nb-Ta-Ti and positive anomaly patterns in Pb of different scales in Figure 5.6 and Figure 5.12, suggest that these groups were affected by both crustal contamination and subduction related enrichment. [START_REF] Lustrino | The circum-Mediterranean anorogenic Cenozoic igneous province[END_REF] indicated that negative Nb-Ta and positive Pb anomalies could be observed as a result of two different processes; namely i) crustal contamination occurring at shallow depth with the addition of subducted sediments to the mantle source of the magma ii) fluidinduced enrichment. There are significant differences between a source enriched by fluid components separated from the subduction slab and a source enriched by a subducted sedimentary component [START_REF] Hawkesworth | U-Th Isotopes in Arc Magmas: Implications for element transfer from the subducted crust[END_REF][START_REF] Elburg | Geochemical trends across an arc-continent collision zone : magma sources and slab-wedge transfer processes below the Pantar Strait volcanoes, Indonesia[END_REF][START_REF] Chiaradia | Enriched Basaltic Andesites from Mid-Crustal Fractional Crystallization, Recharge and Assimilation (Pilavo Volcano, Western Cordillera of Ecuador[END_REF]. According to [START_REF] Chiaradia | Enriched Basaltic Andesites from Mid-Crustal Fractional Crystallization, Recharge and Assimilation (Pilavo Volcano, Western Cordillera of Ecuador[END_REF],, enrichment in aqueous fluid-immobile incompatible elements (Th, La, Zr, Nb) and Th/La, Th/Nb ratios suggest a significant difference in the slab component or in the mantle source. High Th/La ratios (0.28-0.36) and Th values (4-24 ppm) mostly indicate the existence of a subducted sediment component in the mantle source [START_REF] Plank | Constraints from thorium/lanthanum on sediment recycling at subduction zones and the evolution of the continents[END_REF].

However, subduction related magmas which strongly have traces of partial melting or have subducted sediments in their sources. Subduction related magmas are separated from fluid metasomatism affected magmas at the mantle source due to their high Th/Ce>0.15, 87 Sr/ 86 Sr, 206 Pb/ 204 Pb [START_REF] Hawkesworth | U-Th Isotopes in Arc Magmas: Implications for element transfer from the subducted crust[END_REF][START_REF] Guo | Post-collisional, potassic and ultrapotassic magmatism of the northern Tibetan Plateau: Constraints on characteristics of the mantle source, geodynamic setting and uplift mechanisms[END_REF] and low 143 Nd/ 144 Nd, Ba/La [START_REF] Sheppard | Barium and LREE-rich, olivine-micalamprophyres with affinities to lamproites[END_REF]1992[START_REF] Hawkesworth | U-Th Isotopes in Arc Magmas: Implications for element transfer from the subducted crust[END_REF] ratios.

The Th/La, Th, Th/Ce, 87 Sr/ 86 Sr, and 206 Pb/ 204 Pb ratios of Erciyes volcanics vary between (0.08-0.24), (1.84-5.81), (0.04-0.12), (0.703609-0.705084) and (18.95-18.88); respectively (Table 6.5). 143 Nd/ 144 Nd isotope values and Ba/La ratios of the volcanics, except for ER30 (18.08), range between (0.512652-0.512875) and (10.04 -14.299; respectively. Th/La, Th/Ce and Th values of Erciyes samples are mostly lower than designated reference ranges, while Sr, Pb, Nd isotope values are higher and Ba/La ratios are also lower.

Th/La and Th values for HS, OZ and K vary between (0.13-0.17), (0. Th/La and Th/Ce values for HS, OZ and K are generally lower than designated reference ranges, whereas Th values are within designated reference ranges (Table 6.5). These ratios show that the Erciyes stratovolcano was less affected by subducted sediments than HS, OZ and K.

Sr/Th ratio is higher in arc volcanic rocks due to the higher mobility of Sr compared to Th in aqueous fluids [START_REF] Hofmann | Mantle geochemistry:the mesaage from oceanic volcanism[END_REF]. Sr/Th vs. 87 Sr/ 86 Sr diagrams (Figure 6.17a) reveals that Sr isotope ratio is inversely proportional to Sr/Th ratio except for ER13 of this study from the New Erciyes stage and the alkalibasalt ERC96-116 [START_REF] Kürkçüoğlu | Geochemical approach to magmatic evolution of Mt.Erciyes stratovolcano Central Anatolia, Turkey[END_REF]  Enriched mantle sources in the continental lithosphere "The trace element and isotopic compositions of the basalts act as tracers that track the material differentiation and cycling in the mantle" [START_REF] Iwamori | Isotopic heterogeneity of oceanic, arc and continental basalts and its implications for mantle dynamics[END_REF]. Primitive mantle (PM)-normalized trace element diagrams for Geophysical data indicate the absence of a mantle plume and contemporaneous subduction [START_REF] Deniel | The Hasan Dagı stratovolcano (Central Anatolia, Turkey): evolution from calc-alkaline to alkaline magmatism in a collision zone[END_REF] beneath present-day Central Anatolia. As explained before, all four volcanic groups have high 206 Pb/ 204 Pb, moderately high 87 Sr/ 86 Sr and 143 Nd/ 144 Nd, and low oxygen ratios.

 Asthenosphere -Lithosphere interaction

In spite of the existence of many major and trace element data related to Central Anatolian Volcanic Province, there isn't much geophysical, age and isotope data.

In this study, the Quaternary age basaltic volcanism products show a much more complex pattern than expected. There is no record of any mantle xenoliths that determined in the literature for Central Anatolia. Accordingly, we have less information about asthenosphere -lithosphere interaction beneath Central Anatolia.

Recent geophysical studies in Eastern and Western Mediterranean on Europe and Eurasia plates revealed various scenarios regarding crustal thickness, uplift and uplift time, subduction, slab detachment, slab delamination, slab rollback, and slab break-off processes, as well as, new data on mantle-crust relation and asthenosphere-lithosphere interaction [START_REF] Govers | Lithosphere tearing at STEP faults: response to edges of subduction zones[END_REF][START_REF] Biryol | Segmented African lithosphere beneath the Anatolian region inferred from teleseismic P-wave tomography[END_REF]Consentino et al., 2012;[START_REF] Schidgen | Surface experssion of Eastern Mediterranean slab dynamics: Neogene topographic and structural evolution of the SW margin of the Central Anatolian Plateau, Turkey[END_REF][START_REF] Faccenna | Slab detachment beneath eastern Anatolia: A posible cause for the formation of the Noth Anatolian fault[END_REF], 2013[START_REF] Aydar | Central Anatolian Plateau: incision and paleoalimetry recorded from volcanic rocks[END_REF]. One of the most significant of these data is particularly whether the Cyprus slab could singly generate the volcanism in Central Anatolia from Late Miocene until the Quaternary period [START_REF] Biryol | Segmented African lithosphere beneath the Anatolian region inferred from teleseismic P-wave tomography[END_REF]. [START_REF] Bartol | A single cause for uplift of the Central and Eastern Anatolian plateau?[END_REF] showed that the effect of the Cyprus slab, which is presently at 660 km depth, on the surface was limited and proved that it could not generate the Central Anatolian volcanism on its own. Their tomographic results revealed a single slab moving horizontally from the west towards the east, and they suggested a model where instantaneous delamination occurred beneath both the Eastern Anatolian Plateau (EAP) and Central Anatolian Plateau (CAP). Furthermore, they postulated that the "delamination progressed too fast (on geological time scales) to leave a migration footprint in the geological record" [START_REF] Bartol | A single cause for uplift of the Central and Eastern Anatolian plateau?[END_REF].

Comparison of ES, HS, OZ and K

In previous sections, geochronological, geochemical, mineralogical and petrographic information on ES, HS, OZ and K basaltic samples was provided. In this section, the results for the Quaternary basalts from these four regions shall be comparatively discussed. Chondrite and PM [START_REF] Sun | Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes[END_REF] The modeling revealed that the magma chamber(s) of the Erciyes stratovolcano located in the pull-apart basin are relatively closer to the surface. On the other hand, albeit the existence of isotopic enrichment due to lithosphereasthenosphere interaction as related in the previous section, the Erciyes stratovolcano was not affected by crustal contamination as much as HS, OZ and K. Whereas, contrary to Erciyes, the Hasandağ stratovolcano samples are rather more alkaline basaltic products and although spidergrams showed that the affect of crustal contamination was lower than in OZ, the isotope data indicated otherwise (Figure 5.6;Figure 5.12). This substantiates that the source had a heterogeneous chemistry; e.g. the existence of a source mixing (Figure 6.8; Figure 6.16). On the other hand, Obruk-Zengen and Karapınar dispersed volcanism products, with the exception of the stratovolcanoes, have intra-group and intergroup differences. The fact that the majority of Obruk-Zengen alkali products are older than HS and K indicates that deeper magma chamber(s) were active at different periods. However, due to the analogous age range of the samples, it is difficult to speculate on the processes affecting the source(s).

Temporal and spatial evolution of magma

In post-collisional volcanisms, generally calcalkaline products erupted before alkaline products, whereas the majority of alkaline and calcalkaline products from the studied area had formed in the same time interval. The majority of the alkali basalts and basaltic andesites collected from HS, OZ and K, and ES basaltic andesites have particularly the same age range. The temperature and pressure values calculated using the microprobe analysis data revealed the existence of more than one magma chamber, which previous researchers had also indicated this information [START_REF] Aydar | Etude Volcano-Structurale et Magmatologique du Strato-Volcan Hasan Dagı (Anatolie Central-Turquie)[END_REF]Aydar and Gourgaud, 1997;[START_REF] Güçtekin | Hasandağ ve Erciyes (Orta Anadolu) Stratovolkanlarının Jeokimyasal ve Petrolojik Evrimi[END_REF]. The age data show that spatial evolution was more effective in these four regions than temporal evolution. The analogous age ranges of the samples and the fact that the ages of some samples varied only by a few thousand years hindered the ascertainment of temporal evolution. The data sets of the present study and tomographic images of recent studies indicate that it is not really possible to speak of the existence of a present-day plume in Central Anatolia [START_REF] Biryol | Segmented African lithosphere beneath the Anatolian region inferred from teleseismic P-wave tomography[END_REF].

The geochemical data of the present study suggest that these four regions had mainly evolved from the lithospheric mantle.

Furthermore, the identification of an uplift in Mediterranean in recent studies and the 2 km elevation of the Mut-Ermenek Basin [START_REF] Cosentino | Late Miocene surface uplift of the southern margin of the Central Anatolian Plateau, Central Taurides, Turkey[END_REF] are indicative of the activity in Eastern Mediterranean. According to the tomographic images of [START_REF] Biryol | Segmented African lithosphere beneath the Anatolian region inferred from teleseismic P-wave tomography[END_REF], the Isparta Angle corresponds to the STEP related tear between the Aegean and Cyprian trenches. The Gölcük volcanism is located immediately above this STEP related tear. Data on Gölcük volcanism indicate a lithospheric mantle source (Alıcı Şen, 1997. Therefore, the traces of the asthenospheric mantle might have affected the lithospheric mantle not directly but as percolations in Central Anatolia. The model developed by [START_REF] Leat | Quaternary volcanism in Northwestern Colorado: Implications for the roles of asthenosphere and lithosphere in the genesis of continental basalts[END_REF] revealed that the Colorado Quaternary basalts had evolved from three different mantle sources. According to this model, the formation of the Colorado Quaternary basalts had occurred through the partial melting of each of the lithospheric mantles, asthenospheric mantle and the thermal boundary layer of lithospheric mantle.

In this thesis, the spatio-temporal evolution of the Quaternary basaltic volcanism in Central Anatolia has been discussed, using geological, geochronological, mineralogical, petrographical and geochemical data. The basalt ages revealed that the basaltic volcanism is younger than the known data in the geological literature, studied in Central Anatolia. All geochemical data, sources and temporal relations of ES, HS, OZ and K are presented below (Table 6.5).

  Anadolu'daki (Erciyes ve Hasandağ stratovolkanları ile Obruk-Zengen ve Karapınar dağınık volkanizmaları) çarpışma sonrası Kuvaterner bazaltlarının petrolojik ve jeokimyasal özelliklerini ortaya koymuş, Kapadokya'daki magmatizmanın zamansalmekansal evrimine odaklanmıştır. K-Ar jeokronolojisi, aynı konum ve yaşta olan alkali ve kalkalkali bazaltların birlikte varolduğuna işaret etmektedir. Ayrıca, sonuçlar bu bazaltların çok genç (bir kaç bin yıl) olabileceklerini göstermiştir. Kapadokya'daki Kuvaterner bazaltlarının mineralojisi aşağıdaki gibidir: plajiyoklaz, olivin, klinopiroksen, ortopiroksen ve oksitler (manyetit, ilmenit). Ortopiroksen sadece Erciyes bazaltlarında görülürken, Hasandağ ve Obruk-Zengen ve Karapınar volkanizmalarında yoktur. Plajiyoklaz fenokristalinin çoğunlukla dengesiz özellikler göstermesi magma karşım sürecine işaret etmektedir: karmaşık zonlanma (normal, ters, osilasyonlu), eriyik kapanımlarınca zengin konsantrik zonlar, soğurulma özellikleri. Bununla birlikte, gözlemlenen mineraloji, baskın fraksiyonel kristallenme süreciyle de uyumludur. Hesaplanan jeobarometre Erciyesideki magma kökeninin diğer yerlerden daha sığ'da yer aldığını göstermektedir. Jeokimyasal sonuçlar Erciyes ve diğer yerlerin sadece mineralojik farklılığını değil, aynı zamanda yaştaş alkali ve kalkalkali bazaltların birlikteliğini de ortaya koymuştur. Çalışılan tüm bazaltlar LREE (Hafif Nadir Toprak Elementler) ve LILE'ce (İri Katyonlu Litofil Elementler) zengindirler. İzotopik veriler (Sr, Nd, Pb, O) zenginleşmiş litosferik kaynağın önemini göstermiştir. Tüm jeokimyasal veriler ayrıca kıtasal kabuk ve daha önceki bir dalma-batmanın kalıntısı ile kontaminasyon gibi süreçleri ve başka kaynakların izlerini de göstermektedir.Anahtar Kelimeler: Türkiye, OrtaAnadolu, çarpışma sonrası, Kuvaterner, bazaltlar, K-Ar yaşı, mineraloji, petroloji, jeokimya.

  Figure 1.1. These regions are in the Southern part of the Central Anatolian Volcanic Complex. Four zones are considered: Erciyes stratovolcano at east (Figure 1.2), Hasandağ stratovolcano at southwest (Figure 1.3), dispersed volcanism of Obruk-Zengen, at south of Hasandağ (Figure 1.4) and dispersed volcanism of Karapınar, at the south-west of Hasandağ (Figure 1.5). Volcanics in the region crop out in the form of ignimbritic shields, stratovolcanoes, and dispersed volcanism (maar, dome, lava flow and scoria cones).

Figure 1 . 1 :Figure 1 . 2 :Figure 1 . 3 :

 111213 Figure 1.1: Location map of the studied areas (http://www2.jpl.nasa.gov/srtm/)

  HC 2 H 3 O 2 . Groundmass of the rocks was separated following the procedure detailed in[START_REF] Guillou | Dating of the Upper Pleistocene-Holocene volcanic activity of La Palma using the unspiked K-Ar technique[END_REF]. Initially, magnetic separation was made and later phenocrysts and microphenocrysts were removed by means of heavy liquids (diodomethane). K analyses have been made in the "Centre de Recherches Pétrographiques et Géochimiques" at Nancy, France. Ar extraction and the method of analysis are presented inCarbit et al. (1998). The Isotopic composition of Ar and total Ar content were determined applying the unspiked K-Ar technique, (see[START_REF] Cassignol | Range and effectiveness of unspiked potassium-argon dating: experimental groundwork and applications[END_REF] andCarbit et al. (1998)). For calibration reference materials, analytical procedure and the settings of the mass spectrometers used refer to[START_REF] Guillou | Dating of the Upper Pleistocene-Holocene volcanic activity of La Palma using the unspiked K-Ar technique[END_REF] and references therein.

  concentrated in three regions: West, Central and East Anatolia. This thesis considers the Quaternary Erciyes and Hasandağ stratovolcanoes and the dispersed volcanism of Obruk-Zengen and Karapınar, from Central Anatolia, Cappadocia. However, easy to make comparison for regions, Hasandağ stratovolcano, Obruk-Zengen and the Karapınar dispersed volcanisms are collected under the Southwestern Cappadocia volcanism title. A geological map of the studied area was prepared by reference to Pasquare et al. (1988), Le Pennec et al. (1994) and Temel et al. (1998) (Figure 2.1). However, in order to investigate volcanic units in more detail, the geological maps that former investigators prepared for the Erciyes and Hasandağ stratovolcanoes were used, and also the 1/500 000 scaled geological maps of Turkey of MTA (The General Directorate of Mineral Research and Exploration) for the Karapınar and Obruk-Zengen dispersed volcanism. Geological maps related to the studied areas were superposed with SRTM (Shuttle Radar Topography Mission) images. Sampling locations were noted in Figure 2.2 for Erciyes stratovolcano, in Figure 2.3 for Hasandağ stratovolcano, in Figure 2.4 for Obruk-Zengen dispersed volcanism and in Figure 2.5 for Karapınar dispersed volcanism.

Figure 2 . 1 :Figure 2 . 2 :Figure 2 . 3 :Figure 2 . 5 :

 21222325 Figure 2.1: Geological map of the studied areas (modified from Pasquare et al.[START_REF] Dewey | Extensional collapse of orogens[END_REF][START_REF] Le Pennec | Neogene ignimbrites of the Nevşehir plateau, Central Turkey[END_REF][START_REF] Temel | Ignimbrites of Cappadocia: Petrology and Geochemistry[END_REF]

Figure 2. 7 and

 7 Figure 2.8), it will be important to look briefly the major element features and the classification of the samples. The major element analysis and the classification diagram of the samples from the study area can be seen in Table 2.2 and Figure 2.6, respectively. According to Figure 2.6, mostly the samples of the Erciyes stratovolcano are calc-alkaline. On the other hand, Southwestern Cappadocia volcanism samples are alkaline in features. The detail geochemical features of the samples, essential diagrams and related considirations are in Chapter 5.

Figure 2 . 6 :

 26 Figure 2.6: TAS (Total-Alkali Silis) diagram of Erciyes stratovolcano and Southwestern Cappadocia volcanics (Hasandağ stratovolcano, Obruk-Zengen and Karapınar)

  (Figure 2.7).

Figure 2 . 7 :

 27 Figure 2.7: Synthetic stratigraphic section of the Erciyes stratovolcano (not to scale). (Modified from[START_REF] Şen | Erciyes stratovolkanın'nın (Orta Anadolu) volkanolojik ve petrolojik gelişiminin incelenmesi[END_REF][START_REF] Kürkçüoğlu | Erciyes stratovolkanı'nın Jeokimyasal Evrimi, Doktora Tezi[END_REF] . (*[START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF][START_REF] Ercan | Erciyes Dağı Orta Anadolu Pliyo-Kuvaterner volkanizmasina ilşkin yeni jeokimyasal, izotopik, radyometrik veriler ve jeotermal enerji açısından önemi[END_REF][START_REF] Innocenti | The Neogene calc-alcaline volcanic of Central Anatolia: Geochronological data on Kayseri-Niğde area[END_REF]

Figure 2 . 8 :

 28 Figure 2.8: Synthetic stratigraphic columnar section of the Southwestern Cappadocia (not to scale), including Hasandag stratovolcano, Obruk-Zengen and Karapınar dispersed volcanism. (Modified from Aydar and Gourgaud, 2002). (* Aydar and Gougaud, 1998; ** Besang et al., 1977; ***Ercan et al., 1992; ****Kuzucuoğlu et al., 1998; *****[START_REF] Deniel | The Hasan Dagı stratovolcano (Central Anatolia, Turkey): evolution from calc-alkaline to alkaline magmatism in a collision zone[END_REF]

FigureFigure 3 . 2 :Figure 3 . 3 :

 3233 Figure 3.1: Plagioclase phenocryst displaying sieve texture and concentric zoning with glassy inclusions around its margins and centre (ER10, (a) I. Nicol, (b) II. Nicol) (plg: plagioclase)

Figure 3 . 4 :

 34 Figure 3.4: Equilibrium olivine (below right) and gnawed olivine microphenocryst (upper left). Plagioclase microlites (trachytic texture), pyroxene and olivine microlites are observed in the matrix. (ER10, (a) I. Nicol, (b) II. Nicol) (plg: plagioclase, ol: olivine)

Figure 3 . 5 :

 35 Figure 3.5: Clinopyroxene, plagioclase and olivine phenocrysts and microphenocrysts exhibiting glomeroporphyritic texture. (ER10, (a) I. Nicol, (b) II. Nicol) (plg: plagioclase, cpx: clinopyroxene, ol: olivine)

Figure 3 . 6 :

 36 Figure 3.6: Orthopyroxene, plagioclase and olivine phenocrysts and microphenocrysts exhibiting glomeroporphyritic texture. (ER9, (a) I. Nicol, (b) II.Nicol) (opx: orthopyroxene)

.

  Plagioclase (Plg) crystals were formed under equilibrium or disequilibrium conditions. Plagioclases formed under equilibrium conditions are euhedral microphenocrysts and microlites. Plg formed under disequilibrium conditions display sometimes sieve textures. Plg is also present in glomeroporphyritic globules, with olivine (Figure3.7).

Figure 3 . 7 :

 37 Figure 3.7: Plagioclase phenocrysts displaying glomeroporphyritic textures and olivine microphenocrysts (HA31, (a) I. Nicol, (b) II. Nicol) (plg: plagioclase, ol: olivine) Olivine (Ol) crystals formed under equilibrium and disequilibrium conditions were observed together in most of the samples. Crystals formed under equilibrium conditions are usually euhedral phenocrysts and microphenocrysts. The ones formed under disequilibrium conditions are also phenocrysts but with greater sizes and skeletal features with gnawed features beginning from their central parts (Figure 3.8). Olivine is also observed in glomeroporphyritic grains. Sometimes, olivine contains opaque mineral inclusions of spinel. Iddingsitization is sometimes developed within fractures and in central parts of olivine.

Figure 3 . 8 :

 38 Figure 3.8: Olivine phenocrysts and microphenocrysts under equilibrium (upper right) and disequilibrium (lower left) conditions (HA20, (a) I. Nicol, (b) II. Nicol) (ol: olivine)

Figure 3 . 9 :

 39 Figure 3.9: Clinopyroxene microphenocrysts and microlites in a glomeroporphyritic grain (HA13, (a) I.Nicol, (b) II. Nicol) (cpx: clinopyroxene)

Figure 3 . 10 :

 310 Figure 3.10: Plagioclase microlites with pyroxene and olivine crystals within the matrix. (HA31, (a) I. Nicol, (b) II. Nicol) (plg: plagioclase, ol: olivine) 3.2.2. The Basalts s.l. of the Obruk-Zengen Dispersed Volcanism Basalts of the Obruk-Zengen area, at South of Hasandağ stratovolcano, exhibit the following mineralogical assemblage: plagioclase, olivine, clinopyroxene and oxide minerals. The textures are hypocrystalline and porphyritic. The description of the studied samples is given in Table 3.2. Plagioclase (Plg) crystals are usually observed as microphenocrysts and microlites, sometimes as phenocrysts in HA27 (Figure 3.11). Plg phenocrysts in HA27 are subhedral, prismatic and sometimes gnawed and vary from a few hundred microns to few millimeters in size. Plagioclases in equilibrium and in disequilibrium are both present in HA27 (Figure 3.11). Plg formed under

Figure 3 . 11 :

 311 Figure 3.11: Plagioclase phenocrysts and microphenocrysts under equilibrium and disequilibrium conditions. The ones formed under disequilibrium conditions display sieve textures. (HA27, (a) I.Nicol, (b) II. Nicol) (plg: plagioclase)

Figure 3 . 12 :

 312 Figure 3.12: Equilibrium olivine microphenocrysts and disequilibrium olivine phenocrysts (HA16, (a) I.Nicol, (b) II. Nicol) (ol: olivine)

Figure 3 . 14 :

 314 Figure 3.14: Fractured clinopyroxene phenocrysts and microphenocrysts (HA26, (a) I.Nicol, (b) II. Nicol) (cpx: clinopyroxene)

Figure 3 . 15 :

 315 Figure 3.15: Equilibrium (upper left) and disequilibrium (lower left) olivine microphenocrysts. Plagioclase microphenocrysts displaying sub-trachytic texture, pyroxene and olivine microlites in the matrix (HA16, (a) I.Nicol, (b) II. Nicol) (ol: olivine)

  ). Plagioclases are found as phenocrysts, microphenocrysts and microlites in KA19 and KA21 samples, but usually as microphenocrysts and microlites as in KA18. The Plg formed under disequilibrium conditions display sieve textures and cloudy zone in all Karapınar samples(Figure 3.16). Plagioclase is also observed in glomeroporphyritic aggregates.

Figure 3 . 16 :

 316 Figure 3.16: Plagioclase phenocryst displaying sieve texture (KA19, (a) I.Nicol, (b) II. Nicol) (plg: plagioclase)

Figure 3 . 17 :

 317 Figure 3.17: Olivine phenocrysts, microphenocrysts and microlites with subhedral or anhedral crystals with rounded shapes (KA21, (a) I. Nicol, (b) II. Nicol) (ol: olivine)

Figure 3 . 18 :

 318 Figure 3.18: Clinopyroxene phenocrysts, microphenocrysts and microlites (KA19, (a) I. Nicol, (b) II. Nicol) (cpx: clinopyroxene)

Figure 3 . 19 :

 319 Figure 3.19: The matrix is blackish and mainly consists of microlites of plagioclase, clinopyroxene and olivine (KA21, (a) I. Nicol, (b) II. Nicol) (plg: plagioclase, ol: olivine)

Figure 4 . 2 :

 42 Figure 4.2: Compositional variations of olivine of the basaltic (s.l.) rocks from Erciyes stratovolcano. (Tp: Tephroite, Fo: Forsterite, Fa: Fayalite)

Figure 4 . 4 :

 44 Figure 4.4: (a) Composition of Fe-Ti oxides (Bacon and Hirschmann, 1988) of basalts s.l. of Erciyes stratovolcano (b) Cr-Al-(Fe +2 + 2Ti) triangular diagram[START_REF] Melluso | Major and trace element composition of olivine, provskite, clinopyroxene, Cr-Fe-Ti oxides, phlogopite and host kamafugites and kimberlites, Alto Paranaiba, Brazil[END_REF]

  Figure 4.8a-b. Oxides occur as magnetite and secondary ilmenite microlites in the groundmass (Figure 4.8a). Spinels are observed in olivine phenocrysts and/or microphenocrysts of HA13b, HA19 and HA23b samples. They are Cr-spinel and Al-chromite spinel (Figure 4.8b).

Figure 4 . 5 :Figure 4 . 7 :

 4547 Figure 4.5: Compositions of feldspars from basalts s.l. of Hasandağ stratovolcano (An: Anhortite, Ab: Albite, Or: Orthoclase)

Figure 4 . 9 :

 49 Figure 4.9: Composition of the feldspars from basalts s.l. of the Obruk-Zengen dispersed volcanism, in Ab-An-Or diagrams. (An: Anhortite, Ab: Albite Or: Orthoclase)

Figure 4 . 10 :

 410 Figure 4.10: Composition of olivine from the basalts s.l. of the Obruk-Zengen dispersed volcanism (Tp: Tephroite, Fo: Forsterite, Fa: Fayalite)

Figure 4 . 12 :

 412 Figure 4.12: Compositions of feldspars from basalts s.l. of the Karapınar dispersed volcanism Olivine Olivine displays as phenocrysts, microcrysts and microlites (Figure 4.13).

  ).They usually occur as phenocrysts and less microcrysts and microlites. The composition of Cpx is Wo( 41-46 ), En( 40-48 ), Fs( 9-17 ) for phenocrysts and microphenocrysts and Wo( 41-46 ), En( 40-48 ), Fs( 9-16 ) for microlites (Table4.1). The Mg-number displays a restricted range (71-84). Phenocrysts and microcrysts are normally zoned with Mg-rich cores.OxidesOxide occurs as magnetite microlites in KA19 (Figure4.8a). However, there are Cr-spinel and Al-chromite in KA19 and KA21 (Figure4.8b).

Figure 4 . 13 :

 413 Figure 4.13: Composition of olivine from basalts s.l. of the Karapınar dispersed volcanism. (Tp: Tephroite, Fo: Forsterite, Fa: Fayalite)

Figure 4 .

 4 Figure 4.15 shows that olivine-melt equilibrium relations are best depicted in a plot of whole rock Mg number [100 x (Mg+2/Mg+2 + Fe+2)] versus forsterite content of olivine (e.g.[START_REF] Garcia | Petrography and olivine and glass chemistry of lavas from the Hawaiian Scientific Drilling Project[END_REF] with the equilibrium field (KD = 0.3 ± 0.03) shown as the blue band[START_REF] Damasceno | Mineral chemistry of midly alkaline basalts from the 25 Ma Mont Crozier section, Kerguelen Archipelago: constraints on phenocryst crystallization environments[END_REF].

Figure 4 . 15 :

 415 Figure 4.15: Olivine-melt Fe/Mg equilibrium diagram. Whole rock Mg-numbers versus Fo content of olivine is plotted for basalts s.l. of Erciyes. Mg-number = 100*Mg +2 / (Mg +2 + Fe +2 ) is calculated assuming Fe +3 /Fe +2 =0.1. The equilibrium field for Fe/Mg exchange between olivine and the melt (0.3 ± 0.03; Roeder and Emslie, 1970) is shown. Arrows indicate the xenocryst addition and groundmass crystallization

Figure 4 . 16 :

 416 Figure 4.16: Variation of clinopyroxene compositions versus nominal whole rock geochemistry. Cpx -melt Fe/Mg equilibrium diagram. Whole rock Mg-numbers versus Mg-numbers of cpx is plotted. Mg-number = 100*Mg+2/ (Mg+2 + Fe+2) is calculated assuming Fe +3 /Fe +2 = 0.1. The equilibrium field for Fe/Mg exchange between Cpx and the melt (0.23 ± 0.05; (Toplis and Carroll, 1995) is shown. Arrows indicate the relative effects of xenocryst addition and groundmass crystallization. Symbols as in Figure 4.15 ER10 and ER26 are the only samples plotted in the equilibrium field (Figure 4.16). Mostly the clinopyroxenes of Erciyes stratovolcano samples are not in the equilibrium field (Figure 4.16). The samples ER9 and ER32 are not plotted inFigure 4.16 because they only have orthopyroxene.

Figure 4 .

 4 Figure 4.17: Feldspar -melt equilibria. (a) Plagioclase -melt equilibria for Erciyes stratovolcano; KD values are from[START_REF] Sisson | Experimental investigations of the role of H2= in calc-alkaline differentiation and subduction zone magmatism[END_REF]. Symbols as in Figure4.[START_REF]samples from ES were analyzed for 206 Pb/ 204 Pb[END_REF]

Figure 4 .

 4 Figure 4.18: Olivine-melt Fe/Mg equilibrium diagram: Whole rock Mg-numbers versus Fo content of olivine. Mg-number = 100*Mg +2 / (Mg +2 + Fe +2 ) is calculated assuming Fe +3 /Fe +2 =0.1. The equilibrium field for Fe/Mg exchange between olivine and the melt (0.3 ± 0.03; (Roeder and Emslie, 1970) is shown. Arrows indicate the relative effects of xenocryst addition and groundmass crystallization. As shown in Figure 4.18, except the samples HA13b and HA18, the other Hasandağ samples have some cores and rims in the equilibrium field.

Figure 4 . 19 :

 419 Figure 4.19: Variation of clinopyroxene compositions versus nominal whole rock geochemistry in a Cpx -melt Fe/Mg equilibrium diagram. Whole rock Mg-numbers versus Mg-numbers of Cpx Mg-number = 100*Mg+2/ (Mg+2 + Fe+2) is calculated assuming Fe+3/Fe+2 = 0.1. The equilibrium field for Fe/Mg exchange between cpx and the melt (0.23 ± 0.05; Toplis and Carroll, 1995) is shown. Arrows indicate the relative effects of xenocryst addition and groundmass crystallization. Symbols as in Figure 4.18 4.3.2.3. Feldspar Liquid Equilibrium

Figure 4 .

 4 Figure 4.20: Feldspar-melt equilibria. (a) Plagioclase -melt equilibria of Southwestern Cappadocia; KD values are from Sisson and Grove (1993). Symbols same as in Figure 4.18 4.4. Geothermometer and Geobarometer Calculation Magma temperatures for the basalts s.l. of Erciyes and Hasandağ stratovolcanoes, and for dispersed volcanism of Obruk-Zengen and Karapınar were estimated.

Figure 4 .

 4 Figure 4.21, respectively.

Figure 4 . 21 :

 421 Figure 4.21: Temperature vs. SiO 2 of Erciyes volcanics

Figure 4 . 22 :

 422 Figure 4.22: Temperature vs. SiO 2 of Southwestern Cappadocia volcanics

  the equilibrium field (Figure 4.20). Their estimated temperatures are 1207 o C, 1176 o C and 1164 o C, respectively (Table

  1. Most of the samples are intermediate in composition (52% <SiO 2 < 63%), while the loss of ignition (LOI) values of the samples varies between 0.32% and 1.14%. MgO contents range between 6.65 and 3.00 wt%, with Mg# between 53 and 69.The major element values, that are recalculated according to anhydrous basis, are plotted in the total alkaline (Na 2 O% + K 2 O%) vs. silica (SiO %) diagram of Le Bas et al. (1986) (Figure 5.1). The samples of ES are plotted in the trachybasalt, basaltic andesite, basaltic-trachyandesite, andesite and dacite areas (Figure 5.1).

  , 2 of the samples present alkaline characteristics while the remaining 17 samples are subalkaline. It is determined that the trachybasalt and basaltic-trachyandesite samples are respectively hawaiite (Na 2 O-2>K 2 O) and mugearite (Na 2 O-2>K 2 O). The subalkaline samples are calcalkaline in the FeOt, Na 2 O+K 2 O and MgO (AFM) diagram of Irvine and Baragar (1971) (Figure 5.2). In Peccerillo and Taylor's (1976) K 2 O vs. SiO 2 diagram, these samples show also a calcalkaline characteristic, except, ER29 sample that is high calcalkaline (Figure 5.3). According to the Al 2 O 3 > Na 2 O+K 2 O+CaO values, Erciyes lavas display dominantly per aluminous features.

Figure 5 . 1 :

 51 Figure 5.1: Total Alkaline-SiO 2 diagram of Erciyes (Le[START_REF] Bas | A Chemical Classification of Volcanic Rocks Based on the Total Alkali -Silica Diagram[END_REF] Miyashiro,1978)

Figure 5 . 4 :

 54 Figure 5.4: Major oxide variation diagrams of Erciyes

  3) and TAS diagram (Figure 5.1) were given in previous sections. Multi-element patterns display enrichment in all Large Ion Lithophile (LIL) Elements (Rb, Ba, Th, U and Pb) and clear depletion in Nb, Ta, Ti and P. Similarities and some variances in separated LDDS and MDDS groups are: i) In the LDDS group, except Pb, Nb and Ta contents, the samples vary in multielement contents (Figure 5.6 a). The oldest sample ER13 is the only one in LDDS that exhibits Rb, Ba, U and Th depletions and P, Sm, Zr, Hf, Dy, Y, Yb and Lu enrichment. In the sample ER1 and particularly in the youngest sample ER29, Ba, Th, U and Pb elements are displaying enrichments. In contrast, Nd, Zr, Hf, Sm, Eu, Ti, Dy, Y, Yb and Lu are more depleted in ER1. Although ER3 and ER10 have a similar pattern; Ba, Th and U elements are enriched and Ta is depleted in ER3 more than ER10 (Figure 5.6a). ii) MDDS group displays mostly depleted patterns, except Th, U and Pb (Figure 5.6b). Negative anomalies in Nb, Ta, P and Ti elements are characteristic of this group. The sample ER30, that exhibits a moderate differentiation, shows enrichment in Ba, K, and depletion in Ti unlike other samples. ER9 sample is more enriched in Zr and Hf, while ER11 is more enriched in P and Nd.

  Be< L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. < L.D. Cd < L.D. < L.D. < L.D. 0

Figure 5 . 5 :

 55 Figure 5.5: Trace element variation diagrams of Erciyes

Figure 5 . 6 :

 56 Figure 5.6: (a) Less differentiated dated samples (LDDS), (b) More differentiated dated samples (MDDS). Normalized in accordance with PM-spider diagram of Erciyes volcanic rocks (normalized values from Sun and McDonough (1989))

Figure 5 . 7 :

 57 Figure 5.7: (a) Less differentiated dated samples (LDDS), (b) More differentiated dated samples (MDDS). Normalized in accordance with Chondrite -rare earth element diagram of ES volcanics (normalized values and average OIB and E-MORB values are taken from[START_REF] Sun | Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes[END_REF]

Figure 5 . 8 :

 58 Figure 5.8: Southwestern Cappadocia Volcanism basic samples in the total Alkaline vs. SiO 2 diagram (Le Baset al., 1986;[START_REF] Miyashiro | Nature of alkalic rock series[END_REF]

Figure 5 . 9 :

 59 Figure 5.9: K 2 O vs. Na 2 O diagram[START_REF] Middlemost | The basalt clan[END_REF].(Symbols as in Figure5.8).

  2 O 3 > Na 2 O+K 2 O+CaO) indicate that all the samples from Southwestern Cappadocia volcanism are strongly per-aluminous. As seen in the Figure 5.10, Harker variation diagrams of HS, OZ and K. In Al 2 O 3 , Na 2 O, TiO 2 vs. MgO, variation patterns are more likely positive while negative trends are observed in the CaO, Fe 2 O 3 , P 2 O 5 vs. MgO variation diagrams (Figure 5.10). In the samples of the HS, from oldest to youngest (HA18, HA19 and HA20), K 2 O values tend to decrease compare to MgO values (Figure 5.10), moreover the youngest sample of HA31, which is located on the west side of Hasandağ stratovolcano represent the highest Al 2 O 3 , CaO, Fe 2 O 3 , MnO values, and the lowest MgO, SiO 2 , P 2 O 5 , K 2 O values (Figure 5.10). Except the samples HA 16 and HA 17, the negative trend in the major oxides are observed and it is more likely noted that, the samples from OZ do not display clear trends. (Figure 5.10). Although negative trends are observed in Al 2 O 3 , Na 2 O, Fe 2 O 3 , MnO and TiO 2 of K, there is no significant tendency for SiO 2 , K 2 O, CaO and P 2 O 5 (Figure 5.10).According to major element distribution of the Southwestern Cappadocia Volcanism, HS experienced strong fractional crystallization even more dominant compared to ES. However, this strong fractional crystallization pattern is not observed in OZ and K dispersed volcanism. Early crystallization of olivine, pyroxene, Ca-plagioclase and accessory minerals (apatite, magnetite, and ilmenite) is related to the depletion of CaO, MgO, Fe 2 O 3 , P 2 O 5 and TiO 2 . In addition, occurrence of a negative trend in K element, with the increase of MgO, also supports the dominance of fractional crystallization during the magma genesis.The trace element analyses of the volcanic rocks of HS, OZ and K are summarized in Table5.5. Variation diagrams of the Southwestern Cappadocia Volcanism based on selected trace elements versus Th are given in Figure 5.11. In the samples of HS, a positive trend in the incompatible elements Ba, Rb, U, Sr, and a linear decreasing of Hf and Y are observed with increasing Th (Figure 5.11). The increasing trend of Ba, Rb and U elements is related to the differentiation. Increase in Sr and no significant tendency in Eu indicate that Ca-plagioclase fractionation is less effective during the melt formation (Figure 5.11). Moreover negative trends in Hf and Y versus Th is more likely pointing out the latter phases of fractionalization.

  12 a-b-c). Characteristically in the HS group, samples are enriched in LILEs, and show a negative anomaly in Nb, Ta, Ti and P and a positive anomaly in Pb (Figure 5.12 a). Samples of the HS display significant depletion in P, Nd, Zr, Hf, Sm, more than in OIB. General multi-element patterns of the HS group exhibit similar patterns as in OIB, such as Rb, Ba, Th, U, K, La, Sr, Ce, Y, Yb and Lu. However Nb, Ta depletion, Pb spikes, and slightly differences in Hf, Sm, Eu and Ti data, are not truly in agreement with OIB values (Figure 5.12a).All the samples belonging to OZ group are enriched in LILEs as HS group, and they present relatively higher negative anomaly in Nb, Ta, Ti and P (Figure5.12b).Especially, two samples that are quite enriched in MgO (HA16 and HA17) present a high negative anomaly in Nb and Ta. The most differentiated samples (HA26, HA27) present the highest Pb positive anomaly. OZ group resembles OIB in terms of (Ba, Th, U, K, La, Ce, Pr, Sr, Nd, Y, Yb, Lu) elements.

Figure 5 . 10 :

 510 Figure 5.10: Major element oxide variation diagrams of Southwestern Cappadocia Volcanism

Figure 5 . 11 :

 511 Figure 5.11: Trace element vs. Th variation diagrams of Southwestern Cappadocia Volcanism

Figure 5 . 12 :

 512 Figure 5.12: Normalized -according to PM-spider diagrams of the samples belonging to Southwestern Cappadocia Volcanism (a) HS, (b) OZ, (c) K (Normalized values and average OIB and E-MORB values are taken from Sun and McDonough (1989))

Figure 5 .

 5 Figure 5.13: Normalized -according to Chondrite-REE spider diagram of the Southwestern Cappadocia Volcanism (a) HS, (b) OZ, (c) K (Normalized values are the same as in Figure 5.12)

  ) (are shown together in (Figure 5.14). ES volcanics present a clear Sr negative trend while Nd ratios are in slightly increasing (Figure 5.14). In addition to that, the samples are plotted in the mantle area and according to the diagram, their only source material is mantle. The oldest sample ER13 (1695 ka) represents the most possible depleted mantle source compare to other younger phases of the magmatisms. Isotopic compositions of Erciyes stratovolcano have relatively higher 87 Sr/ 86 Sr and lower 143 Nd/ 144 Nd values than OIB and bulk earth (Figure 5.14). Samples of the ES

Figure 5 . 14 :

 514 Figure 5.14: Presentation of Erciyes stratovolcano on Sr-Nd correlation diagram (Data sources; Ito, White and Göbel (1987); Chaffey, Cliff and Wilson (1989);[START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF] Dewey et al., 1990;[START_REF] Cohen | The lead, neodymium and strontium isotopic structure of ocean ridge basalts[END_REF] Ormerod et al.,1988;[START_REF] Hickey | Multiple source basaltic arcrocks from the southern volcanic zone of the Andes (34o-41oS): trace element and isotopic evidence for contributions from subducted oceanic crust[END_REF][START_REF] Aldanmaz | Petrogenetic evolution of Late Cenozoic post-collision volcanism in Western Anatolia,Turkey[END_REF] Çubukçu, 2008. Mantle array and Bulk Earth, Wassenburg et al., (1981) and[START_REF] Faure | Principles of isotope geology[END_REF]; EMI and EMII,[START_REF] Zindler | Chemical Geodynamics[END_REF]

  Figure 5.14: Presentation of Erciyes stratovolcano on Sr-Nd correlation diagram (Data sources; Ito, White and Göbel (1987); Chaffey, Cliff and Wilson (1989);[START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF] Dewey et al., 1990;[START_REF] Cohen | The lead, neodymium and strontium isotopic structure of ocean ridge basalts[END_REF] Ormerod et al.,1988;[START_REF] Hickey | Multiple source basaltic arcrocks from the southern volcanic zone of the Andes (34o-41oS): trace element and isotopic evidence for contributions from subducted oceanic crust[END_REF][START_REF] Aldanmaz | Petrogenetic evolution of Late Cenozoic post-collision volcanism in Western Anatolia,Turkey[END_REF] Çubukçu, 2008. Mantle array and Bulk Earth, Wassenburg et al., (1981) and[START_REF] Faure | Principles of isotope geology[END_REF]; EMI and EMII,[START_REF] Zindler | Chemical Geodynamics[END_REF]

  ). Sr-Nd isotopes vs. Age relations are more systematic in LDDS than MDDS. Calcalkaline ER26 (MDDS) and alkaline ER29 (LDDS) are the same age interval and 87 Sr/ 86 Sr isotope ratio, but ER29 is less radiogenic 143 Nd/ 144 Nd than ER26 (Figure 5.15c-d).

Figure 5 . 15 :

 515 Figure 5.15: (a) 87 Sr/ 86 Sr vs. Age (ka) of LDDS group, (b) 87 Sr/ 86 Sr vs. Age (ka) of MDDS group, (c) 143 Nd/ 144 Nd vs. Age (ka) of LDDS group, (d) 143 Nd/ 144 Nd vs. Age (ka) of MDDS group

Figure 5 .Figure 5 . 18 :

 5518 Figure 5.16: (a) Age(ka) vs. SiO 2 , (b) 87 Sr/ 86 Sr vs SiO 2 , (c) 143 Nd/ 144 Nd vs. SiO 2 diagram of ES

Figure 5 . 21 :

 521 Figure 5.21: Erciyes stratovolcano SiO 2 vs. 206 Pb/ 204 Pb isotope diagram To compare and understand the spatio-temporal evolution of the ES samples, O isotope variation vs. Age (ka) diagram is shown in Figure 5.22. According to the diagram, no significant correlation is observed in LDDS group, however the oldest sample ER13 plots in the lowest O-isotope side, when the sample ER1 display highest δ 18 O value (Figure 5.22). In the similar age group samples of LDDS, ER3 displays higher 18 O/ 16 O isotope ratios than ER10 (Table 5.7). The oldest sample (ER32) in MDDS group has the lowest δ 18 O‰ value as seen the oldest sample of LDDS (ER13). δ 18 O‰ values decrease in the older sample couples of ER30-ER20 to the to younger sample couples of ER17-ER22 and ER9-ER11 (Figure 5.22).

Figure 5 .

 5 Figure 5.22: δ 18 O‰VSMOW vs. Age (ka) correlation diagram of Erciyes stratovolcano

Figure 5 .

 5 Figure 5.23: (a) δ 18 O‰ VSMOW vs. 87 Sr/ 86 Sr isotope correlation diagram, (b) δ 18 O‰ VSMOW vs. SiO 2 diagram of Erciyes stratovolcano

Figure 5 .

 5 Figure 5.24: δ 18 O‰VSMOW vs. 206 Pb/ 204 Pb isotope diagram of Erciyes stratovolcano In comparison with other selected isotope data of the volcanic rocks from different parts of the earth. In 87 Sr/ 86 Sr vs. 143 Nd/ 144 Nd diagram, samples of the Southwestern Cappadocia are plotted in the mantle area presenting a clear negative correlation (Figure 5.25). Samples of the HS yield higher 87 Sr/ 86 Sr and lower 143 Nd/ 144 Nd isotopic ratios compare to OIB and bulk earth isotopic compositions.

  lavas. OZ group is plotted along the mantle array (Figure 5.25). K samples comprise lowest end of the whole group in terms of Nd-isotopic values, besides they are plotted in highest Sr-isotope values as seen Society Islands' samples (Figure 5.25). Isotope values of ES have a higher 87 Sr/ 86 Sr and lower 143 Nd/ 144 Nd values (Figure 5.14) than OIB and bulk

Figure 5 . 25 :

 525 Figure 5.25: Presentation of Southwestern Cappadocia Volcanism on Sr-Nd correlation diagram (Data sources; Ito, White and Göbel(1987); Chaffey, Cliff and Wilson (1989);[START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF] Dewey et al., 1990;[START_REF] Cohen | The lead, neodymium and strontium isotopic structure of ocean ridge basalts[END_REF] Ormerod et al., 1988;[START_REF] Hickey | Multiple source basaltic arcrocks from the southern volcanic zone of the Andes (34o-41oS): trace element and isotopic evidence for contributions from subducted oceanic crust[END_REF][START_REF] Aldanmaz | Petrogenetic evolution of Late Cenozoic post-collision volcanism in Western Anatolia,Turkey[END_REF][START_REF] Çubukçu | Nemrut Stratovolkanının petrolojik Evrimi: Çarpışma Bölgesinde Peralkali Magmatizma[END_REF] Mantle array and Bulk Earth belong toWassenburg et al., (1981) and[START_REF] Faure | Principles of isotope geology[END_REF], EMI and EMII, to[START_REF] Zindler | Chemical Geodynamics[END_REF]

(

  ka), HS display clear positive trend from oldest to youngest sample (HA23b to HA31) (Figure 5.26). OZ group which represents a wide age range and K samples have relatively constant relationship with the increase of the age. In alkaline HS samples, Sr-isotopes increase by the negative tendency of the SiO 2 (Figure 5.27). This relationship is mostly seen in crustal contaminated magmatic systems and/or another radiogenic contribution occurred in the source, which is enriched in 87 Sr/ 86 Sr. No significant correlation between differentiation and spatio-temporal evolution is seen in OZ group, however similar age samples (HA14 and HA15) display similar SiO 2 values in contrast to Sr and Nd isotopes (Figure 5.26; Figure 5.27). Slightly positive trend in Sr and Nd isotopes is seen in the samples of K by increase of SiO 2 and age (Figure 5.26; Figure 5.27).

Figure 5 .

 5 Figure 5.26: (a) 87 Sr/ 86 Sr vs. Age (ka), (b) 143 Nd/ 144 Nd vs. Age (ka) diagram of Southwestern Cappadocia Volcanism

Figure 5 . 27 :

 527 Figure 5.27: Southwestern Cappadocia Volcanism (a) Age (ka) vs. SiO 2 (b) 87 Sr/ 86 Sr vs. Age (ka) diagram c) 143 Nd/ 144 Nd vs. SiO 2 In HS and K samples, according to Sr-Pb and Nd-Pb isotope comparison diagrams, the samples of these groups are also compiled in EMII area (Figure 5.29; Figure 5.30). 87 Sr/ 86 Sr vs. 206 Pb/ 204 Pb and 143 Nd/ 144 Nd vs. 206 Pb/ 204 Pb diagrams of the OZ group display close relationship to MORB area (Figure 5.29; Figure 5.30).

Figure 5 . 28 :

 528 Figure 5.28: 206 Pb/ 204 Pb vs. 207 Pb/ 204 Pb isotope correlation diagram of HS, OZ and K samples belonging to Southwestern Cappadocia Volcanism (Data sources: Rollinson, 1993 (MORB: Mid-oceanic Ridge Basalts, EMI and EMII: Enriched Mantle, DM: Depleted Mantle, PREMA: Prevalent Mantle, HIMU: High µ Mantle, BSE: Bulk Earth, Upper-Lower Crust, NHRL: Northern Hemisphere Reference Line (Symbols are the same as given in 5.19)

Figure 5 . 29 :

 529 Figure 5.29: 206 Pb/ 204 Pb vs. 86 Sr/ 87 Sr isotope correlation diagram of HS, OZ and K samples belonging to Southwestern Cappadocia Volcanism. (Data sources and symbols are the same as given in Figure 5.28)

Figure 5 .

 5 Figure 5.31: 206 Pb/ 204 Pb vs. Age (ka) diagram of HS, OZ and K samples belonging to Southwestern Cappadocia Volcanism

Figure 5 . 32 :

 532 Figure 5.32: SiO 2 vs. 206 Pb/ 204 Pb isotope diagram of HS, OZ and K samples belonging to Southwestern Cappadocia Volcanism

Figure 5 .

 5 Figure 5.33: δ 18 O‰ VSMOW vs. Age (ka) diagram of HS, OZ and K samples belonging to Southwestern Cappadocia Volcanism

Figure 5 . 1 .

 51 Figure 5.35: δ 18 O‰ VSMOW vs. 206 Pb/ 204 Pb isotope diagram of HS, OZ and K samples belonging to Southwestern Cappadocia Volcanism 5.3. Conclusion Representative samples for geochemical analysis of major elements were carried out from Erciyes stratovolcano (ES) (n=19), Hasandag stratovolcano (HS) (n=6), Obruk-Zengen (OZ) (n=6), and Karapınar (K) (n=3) areas. Besides, 29 Sr-Nd, 28 Pb and 28 O isotopic analyses were performed. The purpose of these analyses is to present new geochronological and geochemical (major, trace and isotope elements) data on the Quaternary post collisional basaltic volcanism of Central Anatolia. 1. Most of the samples from ES are intermediate in composition (52% <SiO 2 <63%). The samples of ES are plotted in the trachybasalt, basaltic andesite, basaltictrachyandesite, andesite and dacite areas (Figure 5.1). Two of the samples present alkaline characteristics while the remaining (17) samples are subalkaline.

4. 7 .

 7 We separated the ES samples, LDDS (Less differentiated dated samples) and MDDS (More differentiated dated samples). 5. In LDDS group, except Pb, Nb and Ta contents, the samples vary in multielement contents (Figure 5.6a). MDDS group displays mostly depleted patterns, except Th, U and Pb (Figure 5.6b). Negative anomalies in Nb, Ta, P and Ti elements are characteristic of this group. 6. Negative anomaly for HFS elements (Y, Yb) cannot be seen on multi-element diagrams (Figure 5.6a-b). Probably, the garnet phase is not efficient and La/Nb ratios are (1.52-1.97) in LDDS and MDDS (1.53-2.14) are greater than 1. That means the source is in shallow depths Chondrite normalized Rare Earth Elements (REE) spider diagrams indicate that the ES samples are enriched in Light Rare Earth Elements (LREE) and exhibit flat patterns in MREE and HREE (Figure 5.7).

10.

  Most samples of HS are in the basalt area, one sample is in the trachybasalt field (Figure 5.8). Samples of OZ are also plotted in the basalt area, but one sample is in the trachybasalt field and another one in the basaltic-trachy andesite field (Figure 5.8). K samples are spread in the trachybasalt, basalt and basaltic andesite areas (Figure 5.8). The samples of Southwestern Cappadocia volcanics show dominant alkaline characteristic. 11. All the alkaline samples of the Southwestern Cappadocia Volcanism are plotted in the sodic series area, according to the K 2 O vs. Na 2 O (Figure 5.9).

  of element in liquid  C o = Concentration of element in original solid source D o   X Kd  (X  is the percentage of phase in residual source at the moment the melt begins to rise diapirically from solid source. Kd is the crystal-liquid partition coefficient of the respective element for this mineral.) F=Weight fraction of melt formed. Initial (C o ) values in Equation 1 used in modeling are from McDonough (1990) and Frey (1980) while mineral/melt partition coefficients of elements (Kd) are from Fujimaki et al. (1984); McKenzie and O'Nions (1991); Rollinson (1993) and www.earthref.org/KDD. Overall partition coefficients of rocks (Do) were calculated by multiplying these values with the modal contents of minerals constituting the rocks.

Figure 6 . 1 :

 61 Figure 6.1: Yb vs. La trace element diagram of Erciyes stratovolcano volcanics Garnet peridotite data was obtained from Frey (1980) and spinel peridotite data was obtained from McDonough (1990).

Figure 6 . 2 :

 62 Figure 6.2: Partial melting modeling of Erciyes stratovolcano volcanics using spinel peridotite. (Values were normalized to Chondrite (Sun and McDonough, 1989))

  It is possible to speak of an effective fractional crystallization for Erciyes stratovolcano from Harker variation diagrams plotted using major and trace element data, respectively, given in Chapter 5 (Figure 5.4 and Figure 5.5). A negative trend is not observed for Eu (Eu/Eu*=0.90-1.03) in the multiple element diagram (Figure 5.7). On the other hand, in Figure 6.3, Al 2 O 3 /CaO ratio which remains constant despite the increase in SiO 2 in some samples from LDDS and MDDS groups indicates the occurrence of some plagioclase fractionation.

  For modeling purposes, samples with high Mg#, Cr, Ni, Fe 2 O 3 and MgO and low SiO 2 were Although Quaternary Persani Mountain alkali basalts (Romania) have a strong asthenospheric (OIB-type mantle source) component, their Pb isotopes indicate they were derived from a mantle source affected by an earlier subduction (Downes et al., 1995). On the other hand, Quaternary Karasu basalts, Osmancık-Ceyhan plain basalts, and Huri Hills alkali basalts (Kenya) trace elements and isotope signature indicate asthenospheric mantle source characteristics.

Figure 6 . 4 :

 64 Figure 6.4: Th/Y-Ta/Yb variation diagram of Erciyes volcanics. Data sources[START_REF] Class | Geochemistry of Pliocene to Quaternary alkali basalts from the Huri Hills, northern Kenya[END_REF][START_REF] Polat | Geochemistry of Qaternary basalts erupted along the east Anatolian and Dead Sea Fault zones of southern Turkey: implications fro mantle sources[END_REF] Ormerod et al., 1988;[START_REF] Downes | Petrology and geochemistry of late Tertiary/Quaternary mafic alkaline volcanism in Romania[END_REF][START_REF] Kürkçüoğlu | Geochemical approach to magmatic evolution of Mt.Erciyes stratovolcano Central Anatolia, Turkey[END_REF][START_REF] Kürkçüoğlu | Trace Element Modelling and Source Constraints for Tholeiitic and Calc-Alkaline Basalts from a Depleted Asthenospheric Mantle Source, Mt. Erciyes Stratovolcano, Turkey[END_REF][START_REF] Cebria | Geochemistry of the Quaternary alkali basalts of Garrotxa (NE Volcanic Province, Spain): a case of double enrichment of the mantle lithosphere[END_REF][START_REF] Ma | Petrogenesis of Latest Miocene-Quaternary Continental Intraplate Volcanism along the Northern Dead Sea Fault System (Al Ghab-Homs Volcanic Field), Western Syria: Evidence for Lithosphere-Astnenosphere Interaction[END_REF] Çubukcu, 2008;[START_REF] Özdemir | Volcanostratigraphy and Petrogenesis of Süphan Stratovolcano[END_REF][START_REF] Ali | Alkali basalts from Burgenland, Austria: Petrological constraints on the origin of the westernmost magmatism in the Carpathian-Pannonian Region[END_REF][START_REF] Alıcı | Quaternary tholeiitic to alkaline volcanism in the Karasu Valley, Dead Sea Rift Zone, southeast Turkey: Sr-Nd-Pb-O isotopic and trace-element approaches to crust-mantle interaction[END_REF][START_REF] Alıcı Şen | Anadoluda'ki Kuvaterner Yaşlı Bazaltik Vokaniklerin Kökeni[END_REF][START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF][START_REF] Tang | Asthenoshere-litospheric mantle interaction in an extensional regime: Implication from the geochemistry of Cenozoic basalts from Taihang Mountains, North China Craton[END_REF]

  Figure 6.4b shows that alkaline and calcalkaline samples from various Erciyes stratovolcano stages did not display a systematic relationship and were affected by both subduction related enrichment and crustal contamination. The similar trend observed in Erciyes samples of the present study to Süphan, Nemrut and Tendürek supports the geochemical data given in Chapter 5. In light of the geochemical data, the Erciyes source is considered to be mainly derived from a mantle source.87 Sr/ 86 Sr vs. SiO 2 and Rb/Sr diagrams (Figure6.5) show that LDDS samples from old (ER13) to young (ER1), except for ER29, were affected by crustal contamination. On the other hand, although there was no systematic temporal relationship in MDDS group, fractional crystallization and crustal contamination were effective. The increase observed in both charts supports that both fractional crystallization and crustal contamination were effective.In Th/Y vs. Nb/Y diagram, Erciyes samples range between Th/Nb = 0.1 and Th/ Nb = 1. The ratio of Th/Nb is a good tracer of the source of arc lavas because both

Figure 6 . 5 :Figure 6 . 6 :

 6566 Figure 6.5: (a) 87 Sr/ 86 Sr vs. SiO 2 (b) 87 Sr/ 86 Sr vs. Rb/Sr variation diagrams of Erciyes volcanics.

  Figure 5.9c suggest they were affected by both crustal contamination and subduction-related enrichment.

  C a = concentration of trace element in wall rock C m o = initial composition of trace element in original magma C m = composition of trace element in assimilated rockAFC modeling for isotope ratios (m ) F -z (Equation6)z  ( r  D o -1) / ( r-1)  m o  initial isotope ratio in magma (starting component) m  isotope ratio in magma exposed to AFC processes  a  isotope ratio in wall rock or assimilant rock (assimilant component). Equation6given above was used in isotope AFC modeling for Erciyes stratovolcano. C88-79 (tholeiitic basalt)[START_REF] Kürkçüoğlu | Erciyes stratovolkanı'nın Jeokimyasal Evrimi, Doktora Tezi[END_REF] was used as end member and this sample was Paleozoic-with biotite-moscovite granite of[START_REF] Köksal | Crustal homogenization revealed by U-Pb zircon ages and Hf isotope evidence from the Late Creataceous granitoids of the Ağaçören intrusive suite (Cental Anatolia/Turkey)[END_REF] (Figure6.7a) and plutonic N-26 (monzonite) of İlbeyli (2004) (Figure6.7b), respectively.

Figure 6 . 7 :

 67 Figure 6.7: 143 Nd/ 144 Nd vs. 87 Sr/ 86 Sr AFC modeling diagrams of Erciyes volcanics between end member C88-79 and respectively (a) bmg1 (biotite muscovite granite) and (b) N26 (monzonite). (The values used are as follows: C88-79 (Sr=398.5 ppm, Nd=107 pmm, 87 Sr/ 86 Sr=0.703384, 143 Nd/ 144 Nd=0.512920;[START_REF] Kürkçüoğlu | Erciyes stratovolkanı'nın Jeokimyasal Evrimi, Doktora Tezi[END_REF], bmg-1 (Sr=183 ppm, Nd=35.3 ppm, 87 Sr/ 86 Sr=0.717924, 143 Nd/ 144 Nd=0.512139;[181], and N26 (Sr=911 ppm, Nd=60.12 ppm, 87 Sr/ 86 Sr=0.70804, 143 Nd/ 144 Nd =0.51227;İlbeyli, 2004).

  and Pb isotope data, mixing modeling of the sources with high Pb-and Nd-isotopes and low Sr-isotope identified for the first time as FOZO (Focal Zone) by Hofmann, (1997) and as C (common mantle) by Hannan and Graham, (1996) and the EMII source higher in 87 Sr/ 86 Sr and lower in 143 Nd/ 144 Nd and 206 Pb/ 204 Pb in comparison to the other source was conducted (Figure 6.8).

Figure 6 . 8 :

 68 Figure 6.8: 87 Sr/ 86 Sr vs. 206 Pb/ 204 Pb mixing diagram of Erciyes volcanics and FOZO-EMII mixing modeling. Data sources: EMII, EMI, HIMU, DM[START_REF] Zindler | Chemical Geodynamics[END_REF], NMORB[START_REF] Okamura | Cenozoic magmatism of the north-eastern Eurasian margin: the role of lithosphere versus asthenosphere[END_REF], FOZO[START_REF] Hart | Mantle plumes and entrainment: isotopic evidence[END_REF], Tibet[START_REF] Tang | Asthenoshere-litospheric mantle interaction in an extensional regime: Implication from the geochemistry of Cenozoic basalts from Taihang Mountains, North China Craton[END_REF], Süphan stratovolcano(Özdemir et al., 2011), Society[START_REF] Devey | Active submarine volcanism on the Society hotspot swell (west pacific): A geochemical study[END_REF], Kula[START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF], Basin and Range[START_REF] Kempton | Isotopic and trace element constrains on the composition and evolution of the lithosphere beneath the southwestern United States[END_REF], Kergeluen[START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF].

Figure 6 . 9 :

 69 Figure 6.9: Yb vs. La trace element diagram of Southwestern Cappadocia volcanics. (Garnet peridotite data was from Frey, (1980) and spinel peridotite data from McDonough, 1990).

  Major and trace element Harker diagrams of Southwestern Cappadocia samples given in Chapter 5(Figure 5.10 and Figure 5.11) show that fractional crystallization was not as effective as in Erciyes. Furthermore, plagioclase fractionation was more effective in HS samples than in OZ and K whereas clinopyroxene fractionation was more effective in OZ and K (Figure6.11). Fractional crystallization modeling was explained in detail in Section 6.1.2. Values factored in the selection of Southwestern Cappadocia volcanics used in modeling are given in Table6.3.

Figure 6 . 10 :

 610 Figure 6.10: Partial melting modeling of Southwestern Cappadocia volcanics (a-bc) with spinel peridotite. (Values were normalized to Chondrite (Sun and McDonough, 1989))

  Southwestern Cappadocia plotted similarly to Süphan, Nemrut, Tendürek and Big Pine basalts (Figure6.12a).Özdemir (2011), reported that both lithospheric and asthenospheric mantles are related to the genesis of Süphan stratovolcano and other Eastern Anatolian volcanics (Ağrı, Nemrut, Tendürek), and that lithospheric mantle effect increased from Miocene-Pliocene to Quaternary. A comparison of Southwestern Cappadocia volcanics to the data of previous researchers could not be carried out in Figure6.14, due to the lack of some trace element data.

Figure 6 . 12 :

 612 Figure 6.12: Th/Y vs. Ta/Yb variation diagram of Southwestern Cappadocia volcanics. Data sources[START_REF] Class | Geochemistry of Pliocene to Quaternary alkali basalts from the Huri Hills, northern Kenya[END_REF][START_REF] Notsu | Geochemical features of collision-related volcanic rocks in central and eastern Anatolia, Turkey[END_REF][START_REF] Polat | Geochemistry of Qaternary basalts erupted along the east Anatolian and Dead Sea Fault zones of southern Turkey: implications fro mantle sources[END_REF] Ormerod et al., 1988;[START_REF] Downes | Petrology and geochemistry of late Tertiary/Quaternary mafic alkaline volcanism in Romania[END_REF][START_REF] Kürkçüoğlu | Geochemical approach to magmatic evolution of Mt.Erciyes stratovolcano Central Anatolia, Turkey[END_REF] 2001;[START_REF] Cebria | Geochemistry of the Quaternary alkali basalts of Garrotxa (NE Volcanic Province, Spain): a case of double enrichment of the mantle lithosphere[END_REF][START_REF] Ma | Petrogenesis of Latest Miocene-Quaternary Continental Intraplate Volcanism along the Northern Dead Sea Fault System (Al Ghab-Homs Volcanic Field), Western Syria: Evidence for Lithosphere-Astnenosphere Interaction[END_REF] Çubukcu, 2008;[START_REF] Özdemir | Volcanostratigraphy and Petrogenesis of Süphan Stratovolcano[END_REF][START_REF] Ali | Alkali basalts from Burgenland, Austria: Petrological constraints on the origin of the westernmost magmatism in the Carpathian-Pannonian Region[END_REF][START_REF] Alıcı | Quaternary tholeiitic to alkaline volcanism in the Karasu Valley, Dead Sea Rift Zone, southeast Turkey: Sr-Nd-Pb-O isotopic and trace-element approaches to crust-mantle interaction[END_REF][START_REF] Alıcı Şen | Anadoluda'ki Kuvaterner Yaşlı Bazaltik Vokaniklerin Kökeni[END_REF][START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF][START_REF] Tang | Asthenoshere-litospheric mantle interaction in an extensional regime: Implication from the geochemistry of Cenozoic basalts from Taihang Mountains, North China Craton[END_REF].

Figure 6 .

 6 Figure 6.13: (a) 87 Sr/ 86 Sr vs. SiO 2 , (b) 87 Sr/ 86 Sr vs. Rb/Sr variation diagrams of Southwestern Cappadocia volcanics. (Symbols given in Figure 6.9.)

Figure 6 . 14 :

 614 Figure 6.14: Nb/Y vs. Th/Y variation diagrams of Southwestern Cappadocia volcanics.(Symbols are the same as given in Figure6.12.) (Data sources:Ormerod et al., 1988;[START_REF] Morris | Subduction style magmatism in a Non-subduction setting: The Colville Igneous Complex, NE Washington State,USA[END_REF][START_REF] Çubukçu | Nemrut Stratovolkanının petrolojik Evrimi: Çarpışma Bölgesinde Peralkali Magmatizma[END_REF] Parker, D.F et al., 2010;[START_REF] Özdemir | Volcanostratigraphy and Petrogenesis of Süphan Stratovolcano[END_REF][START_REF] Alıcı Şen | Anadoluda'ki Kuvaterner Yaşlı Bazaltik Vokaniklerin Kökeni[END_REF][START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF][START_REF] Tang | Asthenoshere-litospheric mantle interaction in an extensional regime: Implication from the geochemistry of Cenozoic basalts from Taihang Mountains, North China Craton[END_REF]

  4. References concerning selected contaminants and mineral/melt partition coefficient (Kd) values for basaltic melts are given in Section 6.1.3.1. r values representing the ratio of assimilation rate to fractionation rate given in Equation 6 reveal that exposure to crustal contamination of HS (Figure 6.15a-b), OZ (Figure 6.15c-d) and K (Figure 6.15e-f) ranged between (0.05-0.3), (0.05-0.3) and (0.05-0.1); respectively.

Figure 6 . 15 :

 615 Figure 6.15: 143 Nd/ 144 Nd vs. 87 Sr/ 86 Sr AFC modeling diagrams of (a) Hasandağ stratovolcano samples end member HA23b and contaminant bmg1 (biotite muscovite granite), (b) Hasandağ stratovolcano samples end member HA23b and contaminant N26 (monzonite), (c) Obruk-Zengen samples end member HA26 and contaminant bmg1, (d) Obruk-Zengen samples end member HA26 and contaminant N26, (e) Karapınar samples end member KA19 and contaminant bmg1, (f) Karapınar samples end member KA19 and contaminant N26 (Values obtained from(İlbeyli, 2004) are as follows: bmg-1 (biotite muscovite granite) (Sr=183 ppm, Nd=35.3, 87 Sr/ 86 Sr=0.717924, 143 Nd/ 144 Nd=0.512139;[START_REF] Köksal | Crustal homogenization revealed by U-Pb zircon ages and Hf isotope evidence from the Late Creataceous granitoids of the Ağaçören intrusive suite (Cental Anatolia/Turkey)[END_REF], and N26 (monzonite) (Sr=911 ppm, Nd=60.12 ppm, 87 Sr/ 86 Sr=0.70804, 143 Nd/ 144 Nd =0.51227)

Figure 6 .

 6 Figure 6.16: 87 Sr/ 86 Sr vs. 206 Pb/ 204 Pb mixing diagram of Erciyes volcanics and FOZO-EMII mixing modeling. Data sources: EMII, EMI, HIMU, DM[START_REF] Zindler | Chemical Geodynamics[END_REF], NMORB[START_REF] Okamura | Cenozoic magmatism of the north-eastern Eurasian margin: the role of lithosphere versus asthenosphere[END_REF], FOZO[START_REF] Hart | Mantle plumes and entrainment: isotopic evidence[END_REF], ,Tibet[START_REF] Tang | Asthenoshere-litospheric mantle interaction in an extensional regime: Implication from the geochemistry of Cenozoic basalts from Taihang Mountains, North China Craton[END_REF], Süphan stratovolcano(Özdemir et al.,2011), Society[START_REF] Devey | Active submarine volcanism on the Society hotspot swell (west pacific): A geochemical study[END_REF], Kula[START_REF] Alıcı Şen | Petrogenetic modelling of Quaternary post-collisional volcanism: a case study of central and eastern Anatolia[END_REF], Basin and Range[START_REF] Kempton | Isotopic and trace element constrains on the composition and evolution of the lithosphere beneath the southwestern United States[END_REF], Kergeluen[START_REF] Gautier | Petrology and geochemistry of Kergulelen basalts (South Indian Ocean): evolution of the mantlesources from ridge to an intrplate position[END_REF]

  photography to identify the NW-SE oriented Göğdağ line, the N-S oriented Yılband line, and other potential faults besides the Ecemiş fault. Furthermore, Genç and Yürür (2011) found three different N-S oriented potential normal faults on the Erciyes stratovolcano. The alkali basalt observed along the Göğdağ line was

  from the Koçdağ stage. Whereas, in Figure 6.16b, HS, OZ and K samples of the present study display an alignment from OZ to K exactly as in 87 Sr/ 86 Sr vs. 143 Nd/ 144 Nd diagrams. In this diagram (Figure 6.17b), Deniel et al. (1998) samples plotted within the same range as HS.The samples display a sediment input trend in Ba/La vs. Th/Yb diagrams (Figure6.17b), and Th/Yb and Ba/La values are lower than GLOSS (average) (Global

Figure 6 . 17 :

 617 Figure 6.17: Comparison of Erciyes, Southwestern Cappadocia (HS, OZ and K) and previous research samples with GLOSS (average).

  Figure.6.15). The extent of crustal contamination varies at different regions within the studied area. The lead isotope ratios display EM2-type character for all four volcanic groups (Figure5.17; Figure5.28) and plot above the Northern Hemisphere Reference Line.

Faccenna

  et al. (2013) discussed, how Afar Plume might have affected the Arabian, Anatolian and Aegean systems. According to Cosentino et al. (2012) and Faccenna et al. (2013) the slab window formation at ~8-10 Ma widen westward.The stated event may be the reason of hot material migration from Arabia towards Southeast of Turkey. Karacadağ volcanics are located at the southeast region of Turkey that is lying in the north of Arabian continent. The geochemical data of Karacadağ display both asthenospheric and enriched sub-continental lithospheric mantle source signatures[START_REF] Keskin | The Geochronology and Origin of Mantle Sources for Late Cenezoic Intraplate Volcanism in the Frontal Part of the Arabian Plate in the Karacadağ Neovolcanic Arae of Turkey. Part 2. The Result of Geochemical and Isotope (Sr-Nd-Pb) Studies[END_REF]. According to[START_REF] Keskin | The Geochronology and Origin of Mantle Sources for Late Cenezoic Intraplate Volcanism in the Frontal Part of the Arabian Plate in the Karacadağ Neovolcanic Arae of Turkey. Part 2. The Result of Geochemical and Isotope (Sr-Nd-Pb) Studies[END_REF], the situation may be explained by the Afar Plume. However, In Th/Yb vs. Ta/Yb diagrams (Figure6.4 and Figure6.12) Karacadağ and this thesis samples (ES, HS, OZ and K samples) do not indicate the same trends. Besides, isotopically, Pb and Nd values of Karacadağ samples are higher than ES, HS, OZ and K.Karacadağ and this thesis samples (ES, HS, OZ and K) do not match at the same area in 207 Pb 204 Pb vs. 206 Pb /204 Pb isotope correlation diagram. This result indicates that the effect of the Afar Plume is not being observed in Quaternary basaltic volcanism Central Anatolia according to the findings studied in this thesis. The future studies may help to determine more accurately whether there is a link between Central Anatolia and the Afar Plume or not.

  Figure 2.6 reveals that ES basaltic andesites and andesites are calcalkaline whereas the basalts and basaltic andesites from HS, OZ and K are mostly alkaline. In post-collisional volcanisms, generally calcalkaline products surface before alkaline products, whereas the majority of alkaline and calcalkaline products from the studied area had formed in the same time interval (Figure 2.6;

Figure 6 .

 6 Figure 6.18: (a) Comparison of multielement diagram of ES, HS, OZ and K, (b) Comparison of spidergram of ES, HS, OZ and K. (Values were normalized to

TABLE OF CONTENTS

 OF .1. PURPOSE AND SCOPE.............................................................................................................4 1.2. STUDIED AREAS.........................................................................................................................5 1.3. PREVIOUS STDUDIES IN CAPPADOCIA.................................................................................10 1.4. LABORATORY STUDIES AND ANALYTICAL METHODS........................................................13 1.4.1. Mineraology and Petrography................................................................. CONCLUSION .......................................................................................................................... 59

INTRODUCTION............................................................................................................ 4 1GENERAL GEOLOGY.................................................................................................19 2.1. GENERAL SETTING OF THE STUDIED AREAS IN CAPPADOCIA ........................................ 19 2.2. OVERVIEW ON POST-COLLISIONAL MAGMATISM .............................................................. 26 2.3. THE BASEMENT ROCKS OF CAPPADOCIA .......................................................................... 28 2.4. BRIEFLY OVERVIEW OF THE MAJOR ELEMENT ANALYSIS AND THE CLASSIFICATION OF THE ERCİYES STRATOVOLCANO AND SOUTHWESTERN CAPPADOCIA SAMPLES 28 2.5. THE ERCİYES STRATOVOLCANO ......................................................................................... 31 2.6. THE SOUTHWESTERN CAPPADOCIA VOLCANISM ............................................................. 35 2.6.1. Hasandağ Basaltic Volcanism........................................................................................36 2.6.2. The Obruk-Zengen Dispersed Volcanism......................................................................38 2.6.3. The Karapınar Dispersed Volcanism.............................................................................40 2.7. CONCLUSION.............................................................................................................................40 MINERALOGY AND PETROGRPHY.....................................................................42

3.1. THE BASALTS S.L. OF ERCİYES STROTOVOLCANO ........................................................... 42 3.2. THE BASALTS S.L. OF SOUTHWESTERN CAPPADOCIA ..................................................... 48 3.2.1. The Basalts s.l. of Hasandağ Stratovolcano ................................................................ 48 3.2.2. The Basalts s.l. of the Obruk-Zengen Dispersed Volcanism ....................................... 53 3.2.3. Basalts s.l. of the Karapınar Dispersed Volcanism ...................................................... 56 3.3. MINERAL CHEMISTRY..............................................................................................61 4.1. MINERAL CHEMISTRY OF THE BASALTS S.L. OF THE ERCİYES STROTOVOLCANO ...... 61 4.2. MINERAL CHEMISTRY OF THE BASALTS S.L OF THE SOUTHWESTERN CAPPADOCIA VOLCANISM .................................................................................................................................... 68 4.2.1. The Hasandağ Stratovolcano ...................................................................................... 68 1. INTRODUCTION 1.1. Purpose and Scope

Table 1 . 1 :

 11 Detection limits for major element analyses for ICP-AES

	Major element content
	Oxides%	>10%	>5%	>1%	>0.5%	>0.1%	>0.05%	>0.01%	>0.005%	Limit%
	SiO 2	<1%	-	-	<10%	-	-	-	-	0.5
	Al 2 O 3	<1%	-	-	<10%	-	-	-	-	0.02
	Fe 2 O 3	-	-	<2%	-	<5%	<15%		-	0.01
	MnO	-	-	<1%	-	<5%	-	<10%	-	0.0005
	MgO	-	<2%	<5%	-	-	<10%	-	-	0.02
	CaO	-	<2%	-	<5%	<10%	-	-	-	0.035
	Na 2 O	-	<2%	-	-	<15%	-	-	-	0.03
	K 2 O	-	<2%	-	<5%	<10%	<15%	-	-	0.01
	TiO 2	-	-	-	<5%	-	<10%	-	-	0.001
	P 2 O 5	-	-	<5%	-	<10%	-	-	-	0.05

 ICP-

MS (Inductively Coupled Plasma -Mass Spectrometry) Trace

element analyses have been conducted in Service d'Analyse des Roches et des Minéraux, CRPG -CNRS (Nancy, France) using Perkin Elmer 5000 Mass Spectrometer. The detection limits and uncertainties at given intervals, for trace elements, are given in Table 1.2 (http://helium.crpg.cnrsnancy.fr/SARM/pages/roches.html).

Table 1 . 2 :

 12 Detection limits for trace element analyses and uncertainties for given concentrations

		Trace Element Content
		>50	>10	>1	>0.1	>0.01	Limit		>50	>10	>1	>0.1	>0.01	Limit
		ppm	ppm	ppm	ppm	ppm	ppm		ppm	ppm	ppm	ppm	ppm	ppm
	As	<5% <10%	-	-	-	1.10	Nb	-	<5%	<10% <15%	-	0.06
	Ba	<5% <10%	-	-	-	1.50	Nd	-	-	<5%	<10%	-	0.03
	Be	<5% <10%	-	-	-	0.40	Ni	<5%	-	-	-	-	4.50
	Bi	-	<5%	<10%	-	-	0.10	Pb	-	<5%	<10%	-	-	0.90
	Cd	-	<5%	<15%	-	-	0.12	Pr	-	-	<5%	<10%	-	0.008
	Ce	-	<5%	<10%	-	-	0.10	Rb	-	<5%	<10%	-	-	0.30
	Co <5% <10% <15%	-	-	0.35	Sb	-	<5%	<10%	-	-	0.10
	Cr	<5% <10%		-	-	4.00	Sm	-	-	<5%	<10%	-	0.007
	Cs		<5%	<10%	-	-	0.15	Sn	<5%	<10% <15%	-	-	0.40
	Cu <5% <10%	-	-	-	4.50	Sr	<5%	<10%	-	-	-	1.40
	Dy	-	-	<5%	<10% <15% 0.007	Ta	-	-	<10% <15%	-	0.015
	Er	-	-	<5%	<10%		0.003	Tb	-	-	-	<5%	<10%	0.004
	Eu	-	-	-	<5%	<10% 0.004	Th	-	<5%	<10% <15%	-	0.02
	Ga	-	<5%	<8%	-	-	0.20	Tm	-	-	<5%	<10%	-	0.005
	Gd	-	-	-	<5%	<10%	0.02	U	<5%	<10%	-	<15%	-	0.03
	Ge	-	<5%	<8%		-	0.11	V	<5%	<10%	-	-	-	0.45
	Hf	-	<5%	<10% <15%	-	0.030	W	<5%	<10% <15%	-	-	0.20
	Ho	-	-	<5%	<10%	-	0.001	Y	-	<5%	-	-	-	0.40
	In	-	-	<5%	-	-	0.10	Yb	-	-	<5%	<10%	-	0.003
	La	-	-	<5%	<10%	-	0.06	Zn	<10%	-	-	-	-	14.00
	Lu	-	-	-	<5%	<10% 0.001	Zr	<8%	-	-	-	-	0.80
	Mo	-	<5%	<10%	-	-	0.30

Table 2 .

 2 1. Colors representing the four different regions in Table2.1 will always be used to indicate the same regions throughout the thesis. Purple represents Erciyes stratovolcano, green represents Hasandağ stratovolcano, red for the Obruk-Zengen volcanism and blue for the Karapınar area. Some modifications were made to the stratigraphical sections prepared by former investigators using the new geochronological data obtained in this study.

Table 2

 2

		.1: Dated samples of each group are colored. Puple: Erciyes
	stratovolcano, green: Hasandag stratovolcano, red: Obruk-Zengen, Blue:
	Karapınar
		Erciyes Stratovolcano	Hasandağ stratovolcano and Obruk-Zengen
	Samples	Samples
	ER 1	Scoria cone-(lava flow) N of Develi	HA 13b Lava Flow-Anasultan Hill
	ER 2	Scoria cone-(basalt) N of Develi	HA 14	Olivine Basalt (Aksaray-Adana Road)
	ER 3	Scoria cone-basaltic bomb-W of Ali Dag	HA 15	Scoria Cone-basaltic bomb-(Gamaz)
	ER 4	Basaltic lava flow (İncesu-Kızılören)	HA 16	Scoria cone-(lava flow) Gaffar Hill
	ER 5	Basaltic lava flow (İncesu-Kızılören)	HA 17	Olivine Basalt (Obruk)
	ER 6	Scoria Cone-basaltic bomb-Abas Hill	HA 18	Scoria cone-(lava flow) Near Kızıltepe
	ER 7	Scoria Cone-basaltic bomb-Abas Hill	HA 19	Olivine Basalt (NE of Kızıltepe)
	ER 8	Basaltic lava flow (Kocaoğlan)	HA 20	Olivine Basalt (Ulugüney)
	ER 9	Basaltic lava flow (E of Hcalılar)	HA 21	Olivine Basalt (NW Çardak)
	ER 10 Basaltic lava flow (W of Kızıltepe)	HA 22	Scoria Cone-basaltic bomb-(Mahmutlu)
	ER 11 Scoria cone-(lava flow) S of Hacılar	HA 23	Basaltic Block (Mahmutlu Valley)
	ER 12 Lava flow-Develi Road	HA 24	Scoria cone-bomb-(S of Hasandag)
	ER 13 Basaltic Lava (SE of İncesu)	HA 25	Scoria cone-bomb-(Çukurkuyu)
	ER 14 Basaltic Lava (SE of İncesu)	HA 26	Scoria cone-bomb-(Çukurkuyu)
	ER 15 Basaltic Lava (SE of İncesu)	HA 27	Basaltic lava flow (W of Altınhisar)
				Basaltic lava flow (Aksaray-Adana
	ER 16 Olivine-Basaltic Lava (SE of İncesu)	HA 28	Road)
	ER 17 Basaltic Lava (Sürtme Plateau)	HA 29	Basaltic Block (Gözlükuyu)
	ER 18 Andesite-(Şeyhşaban)	HA 30	Andesite (Taşpınar)
	ER 19 Basaltic Lava (Şeyhşaban)	HA 31	Scoria cone-(Karacaören)
	ER 20 Basaltic Lava (Şeyhşaban)	HA 32	Andesite (N of Karaköy)
	ER 21 Rhyodacite (S of Erciyes)	HA 33	Andesite ( Hasandağ)
	ER 22 Fissure eruption basalt (Karagüllü)	HA 34	Andesite (Hasandağ)
	ER 23 Scoria cone-(basalt)
	ER 24 Rhyodacite (S of Erciyes)
	ER 25 Scoria cone-(lava flow) Siharslan Hill		Karapınar
	ER 26 Scoria cone-(lava flow) Avşar Village	Samples
	ER 27 Cora Maar	KA 18	Scoria cone-(lava flow) Meke Mountain
	ER 28 Dacite	KA 19	Scoria cone-(lava flow) Meke Maar
	ER 29 Scoria Cone-basaltic bomb	KA 20	Dyke-Karapınar Exit
	ER 30 Scoria Cone-basaltic bomb(S of Erciyes)	KA 21	Scoria cone-bomb-(Kumsivri Hill)
	ER 31 Fissure eruption basalt (Diikartın)	KA 22	Dacite
	ER 32 Scoria Cone (Kızıltepe)	KA 23

Table 2 . 2 :

 22 Major element analysis of Erciyes stratovolcano and Southwestern Cappadocia volcanics

		ER1	ER2	ER3	ER4	ER5	ER9	ER10 ER11 ER13 ER16 ER17 ER18 ER20 ER22 ER25 ER26	ER27	ER29	ER30 ER32
	Major element(%)
	SiO2	54.34	55.33 53.13 62.02 60.25 57.34 53.09 56.70 48.89 62.70 55.46 55.13 54.53 57.37 57.15 56.43	55.01	52.45	55.07 56.22
	Al2O3	17.17	17.32 16.52 16.67 16.19 17.64 16.95 17.65 17.06 16.38 17.57 16.96 17.56 18.24 17.57 17.98	17.42	17.68	17.40 17.78
	Fe2O3	6.88	6.97	8.24	4.87	5.55	7.07	8.39	7.22 11.99 4.85	7.27	7.43	7.24	6.27	6.70	6.57	6.81	8.96	7.94	6.55
	MgO	6.10	5.62	6.54	3.00	4.06	4.21	6.65	4.04	5.44	2.86	4.95	5.16	5.88	4.67	4.59	4.59	5.62	4.78	4.84	5.12
	CaO	8.32	8.13	8.54	6.14	6.74	7.18	8.54	7.06	8.46	5.95	7.54	7.58	8.22	8.03	7.58	8.20	8.28	7.54	7.42	7.93
	Na2O	3.48	3.66	3.62	3.72	3.67	4.08	3.81	4.08	4.17	3.71	3.97	4.23	3.70	3.52	3.74	3.80	3.64	4.31	4.06	3.65
	K2O	1.24	1.37	1.02	1.67	1.63	1.23	0.96	1.24	0.94	1.74	1.54	2.05	1.36	1.10	1.18	1.31	1.14	1.65	1.62	0.95
	TiO2	0.96	1.04	1.30	0.66	0.78	1.07	1.36	1.05	2.40	0.65	1.11	1.49	1.10	0.79	0.89	1.04	1.01	1.54	1.39	0.94
	MnO	0.11	0.11	0.13	0.08	0.09	0.12	0.13	0.12	0.18	0.08	0.12	0.13	0.12	0.10	0.11	0.11	0.11	0.15	0.13	0.10
	P2O5	0.36	0.33	0.37	0.19	0.23	0.37	0.40	0.45	0.51	0.19	0.38	0.33	0.36	0.25	0.37	0.34	0.33	0.66	0.41	0.28
	LOI	0.23	0.28	-0.16	1.14	0.99	-0.19	-0.10	0.30 -0.32	1.09	0.30	0.18	0.29	0.47	0.50	0.08	0.42	0.15	0.50	0.58
	Mg#	69.06	66.99

66.61 61.59 65.60 60.78 66.60 59.28 53.29 61.38 63.17 67.13 66.00 64.08 63.72 67.27 58.18 61.34 66.31 Total 99.19 100.15 99.25 100.15 100.19 100.12 100.18 99.91 99.73 100.22 100.20 100.65 100.36 100.81 100.39 100.42 99.79 99.87 100.79 100.09

		Hasandag stratovolcano	Obruk-Zengen	Karapınar
		HA13 b HA18 HA19 HA20 HA23b HA31	HA14 HA15 HA16 HA17 HA26 HA27	KA18 KA19 KA21
	Major element(%)
	SiO2	49.

33 51.06 50.43 50.36 50.90 49.24 48.99 49.38 48.81 48.88 49.39 56.24 49.75 50.87 52.40 Al2O3 16.08 16.86 16.56 16.25 16.22 17.80 16.24 16.40 15.79 15.30 16.23 17.08 16.48 17.65 15.99 Fe2O3

		8.88	8.72	8.87	9.14	8.86	9.57	9.01	9.42	8.97	8.60	9.39	7.31	8.53	9.17	8.20
	MgO	8.52	7.31	7.99	8.75	7.35	6.01	8.52	8.71 10.18 10.92	8.81	4.07	8.12	5.69	8.54
	CaO	9.78	8.76	9.42	9.85	9.32	10.68	9.28	8.98 10.43 10.86	9.47	7.57	11.02	9.52	9.11
	Na2O	3.44	3.86	3.64	3.64	3.68	3.70	3.65	3.71	3.43	3.00	3.73	4.19	3.36	3.96	3.50
	K2O	1.15	1.46	1.26	1.12	1.10	0.97	1.45	1.23	0.80	0.88	1.15	1.86	0.95	1.13	1.12
	TiO2	1.19	1.43	1.33	1.21	1.23	1.34	1.40	1.50	1.10	1.06	1.49	1.25	1.03	1.27	1.00
	MnO	0.15	0.14	0.15	0.15	0.15	0.16.	0.15	0.15	0.15	0.14	0.15	0.13	0.14	0.15	0.14
	P2O5	0.44	0.43	0.44	0.43.	0.37	0.38.	0.43	0.41	0.37	0.25	0.41	0.31	0.30	0.35	0.33
	LOI	-0.14	-0.43 -0.58 -0.27	0.00	-0.06	-0.35 -0.28 -0.32	-0.23	0.22	0.24	-0.32	-0.38	0.12
	Mg#	69.16	67.82 67.79 69.11 65.98 59.50	70.41 68.37 72.62 74.80 68.68 59.19	68.99 60.97	72.38
	Total	98.72	99.

88 99.72 100.64 98.97 99.51 98.69 99.32 99.75 99.83 100.42 100.23 99.35 99.38 100.43

Table 2 .3: New

 2 K-Ar ages from the Erciyes stratovolcano. (a and b represent the 1 st and 2 nd analyses of the samples)

	Sample names	Molten weight (g)	40Ar* (%)	40Ar* (

10 -13 mol/g) 40Ar* weighted mean(± 1s) K* (wt.%) Age  2Ma ER9 (TU-ER-23)

		a b	1.00232 0.93462	-0.376 -0.214	<0 <0		1.212 ± 0.012	<0.001
	ER11	a b	1.00758 1.00562	-0.393 -0.097	<0 <0		1.046 ± 0.011	<0.001
	ER29	a b	1.04062 1.50364	0.085 0.107	0.276 0.318	0.292 ± 0.057	1.345 ± 0.013	0.013 ± 0.005

ER26 (TU-ER-45)

		a b	1.49077 1.41079	0.209 0.22	0.42 0.523	0.471 ± 0.107	1.104 ± 0.011	0.025 ± 0.008
	ER22	a b	1.00075 1.01479	0.247 0.289	0.619 0.66	0.638 ± 0.052	0.930 ± 0.009	0.040 ± 0.007
	ER17	a b	1.00525 1.50996	1.145 0.581	1.107 0.921	0.999 ± 0.058	1.287 ± 0.013	0.045 ± 0.005
	ER1	a b	1.0115 1.00877	0.209 0.199	1.65 1.722	1.670 ± 0.097	1.038 ± 0.010	0.093 ± 0.011

ER30 (TU-ER-30)

		a b	1.50434 1.4951	0.905 0.856	2.731 2.414	2.578 ± 0.115	1.453 ± 0.015	0.102  0.007
	ER20	a b	1.00569 1.00353	0.566 0.524	2.239 2.328	2.295 ± 0.062	1.146 ± 0.011	0.115 ± 0.007
	ER10	a b	0.49442 0.50032	1.033 1.177	4.619 4.373	4.403 ± 0.105	0.855 ± 0.009	0.297 ± 0.015
	ER3	a b	0.49442 0.50032	1.033 1.177	4.619 4.373	4.403 ± 0.105	0.855 ± 0.009	0.352 ± 0.009
	ER32	a b	1.01111 1.5034	6.358 7.08	10.061 10.487	10.280 ± 0.044	0.836 ± 0.008	0.707 ± 0.015
	ER13	a b	0.49576 1.01285	17.302 25.758	24.527 24.315	24.406 ± 0.105	0.830 ± 0.083	1.695 ± 0.037

Table 2 .4: New

 2 K-Ar ages of volcanic samples from Hasandağ stratovolcano, Obruk-Zengen and Karapınar dispersed volcanisms. (a and b represent the 1 st and 2 nd analyses of the samples)

	Sample names	Molten	40Ar*	40Ar*
		weight (g)	(%)	(10

-13 mol/g) 40Ar* weighted mean(± 1s) K* (wt.%) Age  2Ma Hasandağ stratovolcano HA31

			a b	1.05637 1.50318	0.018 0.022	0.038 0.028	0.031 ± 0.052	0.847 ± 0.009	0.002 ± 0.007
		HA13b	a b	0.99537 1.50806	0.816 0.797	0.373 0.343	0.355 ± 0.042	1.079 ± 0.011	0.019 ± 0.005
		HA20	a b	1.00576 1.00321	1.15 0.879	0.989 1.049	1.028 ± 0.047	1.038 ± 0.010	0.057 ± 0.005
		HA19	a b	1.00486 1.28385	1.927 2.132	1.592 1.518	1.540 ± 0.041	1.129 ± 0.011	0.079 ± 0.004
		HA18	a b	1.00058 1.50051	1.774 2.412	2.237 2.136	2.199 ± 0.052	1.212 ± 0.012	0.105 ± 0.005
		HA23b	a b	0.99697 2.00253	9.86 8.005	9.3 9.446	9.377 ± 0.031	0.996 ± 0.010	0.543 ± 0.012
		HA17							0.066± 0.007
		HA27	a b	1.0037 1.02372	1.85 1.616	9.364 9.214	9.300 ± 0.046	1.619 ± 0.016	0.331 ± 0.007
	Obruk-Zengen	HA14	a	0.5015	4.09	8.455	8.415 ± 0.059	1.229 ± 0.012

0.395 ± 0.01

		b	1.03149	4.938	8.41
	HA15	a	1.02037	5.091	7.547	7.568 ± 0.049	1.079 ± 0.011

0.404 ± 0.01

			b	1.49874	5.675	7.573
		HA26	a b	0.4802 0.93817	5.862 4.847	12.135 12.16	12.155 ± 0.070	1.038±0.01	0.675 ±0.016
		HA16	a b	1.00134 1.50996	12.273 4.996	9.055 9.106	9.086 ± 0.071	0.656 ± 0.007	0.799 ± 0.02
		KA19							<0.001
	Karapınar	KA21 KA18	a b	0.50028 0.50674	0.756 0.855	3.152 3.26	3.162 ± 0.091	1.121 ± 0.012	0.163 ± 0.01 0.

280 ± 0.0071 (CK89-19)

Table 3 .1: Petrographic description of samples of Erciyes stratovolcano Samples Macroscopic features Freshness Rock Texture Major crystals Groundmass Alteration ER1

 3

		Dark gray colored with		Hypocrystalline porphyritic,
		alkaline feldspars and small white inclusions Moderately vesicular	×	vesicular Embayed, skeletal triangular shape ol gnawed and phenocrysts. Moderately	Plg Ol Cpx	pilotaxitic plg, ol oxide and cpx	serpentinization, oxidation
		Consolidated, bright grey		Hypocrystalline	porphyritic
	ER2	colored very small white inclusions with	×	Mostly embayed, gnawed and skeletal triangular shape ol phenocrysts Less vesicular	Plg Ol Cpx	pilotaxitic plg, ol oxide and cpx	serpentinization, oxidation
						than ER1
		Light grey colored with
	ER3	alkaline feldspars and v e r y s m a l l , w h i t e inclusions Highly vesicular	×	Hypocrystalline porphyritic Mostly embayed, gnawed and phenocrysts. Highly vesicular skeletal triangular shape ol	Plg Opx Ol Cpx	pilotaxitic plg, ol. oxide and pyx	oxidation
		Dark grey colored with		Hypocrystalline	porphyritic,
		alkaline feldspars and
	ER4	v e r y inclusions	s m a l l ,	w h i t e	×	Mostly gnawed	spongy euhedral	cellular, plg	Plg Cpx	pilotaxitic plg, oxide and cpx	oxidation
						phenocrysts, with spiky cpx.
		Highly vesicular			Highly vesicular
						Hypocrystalline porphyritic
						Spongy	cellular,		gnawed,
	ER5	Consolidated, light grey colored with small white inclusions	×	euhedral plg phenocrysts and some of them show oscillatory zoning	Plg Ol Cpx Opx	pilotaxitic plg, oxide and cpx	oxidation
						Glomeroporphyritic texture
						Moderately vesicular
						Hypocrystalline porphyritic
						Spongy	cellular,		gnawed
	ER8	Consolidated, dark grey colored with alkaline feldspars	×	euhedral plg phenocrysts and some of them show oscillatory zoning	Plg Ol Cpx Opx?	pilotaxitic plg and oxide.	oxidation
						Glomeroporphyritic texture
						Moderately vesicular
						Hypocrystalline porphyritic,
	ER9	Consolidated, dark grey colored with small white inclusions	×	Gnawed microphenocrysts. euhedral	plg	Plg Opx Cpx?	glassy with few phenocrysts	dusty zones
						Glomeroporphyritic texture
						Hypocrystalline	porphyritic.
	ER10	Consolidated, light grey colored with small olivine, pyroxene and some brownish staffs	×	Spongy euhedral Skeletal olivine phenocrysts. cellular, gnawed plg phenocrysts Glomeroporphyritic texture (cpx)	Plg Ol Cpx	pilotaxitic plg, ol, cpx and oxide	serpentinization

Table 3 .1: continued

 3

	ER11	Consolidated, grey small phenocrysts	dark colored, alkaline	×	Hypocrystalline Spongy cellular, gnawed euhedral plg porphyritic phenocrysts and some of them show oscillatory zoning	Plg Ol (few) Cpx (few) Opx	pilotaxitic plg, oxide, cpx	oxidation
					Hypocrystalline	porphyritic
	ER11M	Consolidated, enclave is dark brown and the matrix is light-grey colored with small white	×	Enclave is formed with plg and ol aggregates with black matrix. Outside of enclave is formed of few gnawed plg and cpx, ol phenocrysts.	Plg Cpx Ol	pilotaxitic plg, cpx, ol and oxide
		inclusions.			The intersection part of enclave and
					the whole-rock is light brown colored
					with plg microlites
		Light grey colored		Holocrystalline	porphyritic
	ER13	with phenocrysts	white	×	Embayed ol phenocrysts	Plg Ol Cpx	pilotaxitic plg, oxide, cpx, ol	oxidation and iddingsite
		Moderately vesicular		Moderately vesicular
	ER16	Dark grey colored. with some small, white inclusions and brownish staffs. Moderately vesicular	×	Hypocrystalline porphyritic, Spongy cellular, gnawed euhedral plg, ol phenocrysts	Plg Ol Amp?	pilotaxitic plg, oxide, cpx (few)	oxidation
					Moderately vesicular
					Hypocrystalline porphyritic
	ER17	Consolidated dark grey colored olivine phenocrysts	×	Less vesicular Spongy cellular, phenocrysts, with euhedral and gnawed plg skeletal olivine phenocrysts	Plg Ol	pilotaxitic plg, oxide, cpx (few)	oxidation
					Hypocrystalline porphyritic
	ER20	This sample is similar to ER-17.	×	Ol phenocrysts and some of them are skeletal texture. Less vesicular.	Plg Ol Pyx	pilotaxitic plg, pyx, oxide	oxidation
		Mostly consolidated		Hypocrystalline porphyritic
	ER22	and colored, with big white and dark grey	×	Spongy cellular, gnawed euhedral plg phenocrysts and some of them show oscillatory zoning.	Plg Ol (few)	pilotaxitic plg, ol, oxide, cpx (few)	oxidation
		green crystals			Glomeroporphyritic texture
					Hypocrystalline	seriate
					porphyritic
	ER25	Consolidated, grey colored with dark small white inclusions	×	Spongy cellular, gnawed euhedral plg phenocrysts	Plg Ol	pilotaxitic plg, ol, oxide, cpx? (few)	oxidation
					with
					Ol microphenocrysts

Table 3 . 2 :

 32 Petrographic description of basalts s.l. of Hasandağ stratovolcano, Obruk-Zengen and Karapınar dispersed volcanism area

	Hasandag	Macroscopic		Rock		Major
	stratovolcano	features	Freshness	Texture	crystals	Groundmass	Alteration
	HA13 a	Dark grey colored with olivine phenocrysts and some very small, white inclusions	×	Hypocrystalline porphyritic. Glomeroporphyritic texture	Plg Cpx Ol	pilotaxitic plg, cpx, ol and oxide	Oxidation, serpentinization
		Highly vesicular		Moderately vesicular
					Hypocrystalline
					porphyritic
		Consolidated,
	HA13 b	light grey colored with small white inclusions	×	Skeletal phenocrysts some of them are olivine and disequilibrium	Plg Ol Cpx	pilotaxitic plg, cpx, ol and oxide	serpentinization
		Less vesicular
					Less vesicular than
					HA13a
	HA18	Consolidated, with some vesicles Light brown and grey colored with	×	Hypocrystalline porphyritic Embayed olivines, phenocrysts	Plg Ol Cpx	pilotaxitic plg, ol, cpx? and oxide	oxidation, serpentinization
		olivine phenocrysts			Moderately vesicular.
					Hypocrystalline
					porphyritic
		Light	grey
	HA19	colored olivine crystals with	×	Embayed, and skeletal	gnawed olivines	Plg Ol Cpx	pilotaxitic plg, ol and oxide	oxidation, serpentinization
		Highly vesicular		phenocrysts
					Highly vesicular
					Hypocrystalline
		Consolidated with		porphyritic
	HA20	some vesicles Light grey, olivine phenocrysts	×	Mostly embayed and gnawed olivines phenocrysts	Plg Ol Cpx	pilotaxitic plg, ol and oxide	oxidation
					Less vesicular.
					Hypocrystalline
					porphyritic.
					.
	HA22	Dark grey-black colored. Highly vesicular,	×	Anhedral cellular phenocrysts	spongy plg	Plg Ol Cpx	pilotaxitic plg, ol, cpx and oxide	oxidation, serpentinization
					Highly vesicular
		Consolidated, light grey colored		Hypocrystalline porphyritic
	HA23b	with very inclusions vesicular Moderately	white	×	cpx phenocrysts Cloudy texture plg phenocrysts with gnawed olivine and	Plg Ol Cpx	pilotaxitic plg, ol, cpx and oxide	oxidation
					Moderately vesicular
					Hypocrystalline
					porphyritic
	HA31	Consolidated, light grey colored with small white inclusions	×	Glomeroporphyritic texture	Plg Ol Cpx	pilotaxitic plg and few ol, cpx and oxide

Table 3 .2: continued

 3

		Macroscopic		Rock	Major
	Obruk-Zengen	features		Freshness	Texture	crystals Groundmass	Alteration
		Dark grey colored with olivine phenocrysts		Hypocrystalline porphyritic
	HA14	and inclusions small,	white	×	Glomeroporphyritic texture	Plg Ol	pilotaxitic plg, cpx, ol and oxide	oxidation
						Cpx
		Highly vesicular			Highly vesicular
		Highly vesicular			Hypocrystalline porphyritic
	HA15	Dark grey colored with olivine phenocrysts and small, white	×	Glomeroporphyritic texture Highly vesicular	Plg Ol Cpx	pilotaxitic plg, cpx, ol and oxide	oxidation
		inclusions
					Hypocrystalline porphyritic
		Consolidated, light			Plg
		grey colored with small			Ol	pilotaxitic plg,
	HA16	white inclusions		×	Embayed and gnawed olivine phenocrysts	Cpx	cpx, ol and oxide	oxidation and iddingsite
		Less vesicular			Less vesicular
		Dark grey colored with
		olivine phenocrysts		Hypocrystalline porphyritic
		and some small, white
		inclusions
	HA17	Moderately vesicular	×	Embayed and gnawed olivine phenocrysts	Plg Ol Cpx	pilotaxitic plg, cpx, ol and oxide
					Moderately vesicular
					Hypocrystalline porphyritic
	HA24	Light grey-brown colored Highly vesicular		×	Dark brown colored part is with ol and cpx. Outside of dark brown part is formed of the same crystals Highly vesicular	Plg Ol Cpx	pilotaxitic plg, ol, cpx and oxide	oxidation
		Dark brown colored		Hypocrystalline porphyritic
	HA26	Highly vesicular		×	Gnawed ol and cpx phenocrysts Highly vesicular	Ol Cpx Plg	pilotaxitic plg, ol, cpx and oxide	oxidation, serpentinizatio n
					Hypocrystalline porphyritic
	HA27	Light grey colored with alkaline feldspars	×	Spongy cellular plg phenocrysts and microphenocrysts	Plg Ol Cpx	pilotaxitic plg, ol, cpx and oxide	oxidation, iddingsite
		Moderately vesicular		Moderately vesicular

Table 3 .2: continued Karapınar Macroscopic features Freshness Rock Major

 3

	Texture	crystals	Groundmass	Alteration

Table 4

 4

	.1. Olivine occurs as phenocrysts, microphenocrysts and microlites (Figure
	4.2). Generally, they display a wide compositional range, Fo% ( 57-86 ) for phenocrysts
	and microphenocrysts, and Fo% ( 66-83 ) for microlites.

Table 4 .

 4 On the other hand, the oldest sample ER13 (1.695±0.037 Ma) has few olivine sections and the compositional range is restricted (Figure4.2). Most of olivines are normally zoned with respect to Mg, Fe, but some exhibit reversed zone such as ER10, ER17, ER22, ER27 and ER30.

	Clinopyroxene
	Clinopyroxene (Cpx) occurs as needle-like microphenocrysts and microlites but
	they have been observed also as phenocrysts in ER10 ER22, ER26 and ER27.
	Most phenocrysts are diopside and augite in composition (Figure. 4.3) (Morimoto,
	1989). Cpx occurs only as microlites in ER13 and ER29 and ER30 (Figure 4.3).
	The composition of clinopyroxene is Wo( 33-46 ), En( 42-52 ), Fs( 9-22 ) for phenocrysts
	and microphenocrysts and Wo( 23-47 ), En( 31-52 ), Fs( 7-22 ) for microlites (Table 4.1).
	Opx and Cpx coexist in samples ER1, ER3, ER11, ER17, ER20 and ER22. Cpx of
	these samples are augite and/or diopside with composition Wo( 23-44 ), En( 42-57 ),
	Fs( 9-23 ) and Opx are enstatite and pigeonite with composition Wo( 3-9 ), En( 65-82 ),
	Fs( 15-30 ). Except ER3 (0.352±0.009 Ma), the other samples with Opx and Cpx
	coexisting are younger and their ages vary between 0.115 and <0.001 M. ER9 and
	ER32 have only Opx (enstatite) (Figure 4.3). Normally zoned Opx phenocrysts,
	with Mg-rich cores, coexist with reversed-zoned Opx phenocrysts, with Mg-rich
	rims, in ER3, ER9 and ER32. The Mg-numbers of orthopyroxene are ranging
	between 69 and 84.

1: Average minerals compositions of basalts s.l. in the 4 studied areas

Figure 4.1: Compositions of feldspars (mole %) from Erciyes stratovolcano basalts s.l. (An: Anhortite, Ab: Albite, Or: Orthoclase)

The Mg-numbers of clinopyroxenes display a wide range (59-87). Oscillatory zoning clinopyroxenes are common but some clinopyroxenes are weakly zoned.

Normal-zoned clinopyroxene phenocrysts, with Mg-rich cores, coexist with reversed-zoned clinopyroxene phenocrysts with Mg-rich rims, in the samples ER10, ER17, ER26 and ER27.

Orthopyroxene

The compositions of Opx are listed in Table

4

.1. Orthopyroxene (Opx) minerals are usually present as phenocrysts, microphenocrysts and microlites (Figure

4

.3).

Table 4

 4

	phenocrysts and microphenocrysts and Wo( 41-45 ), En( 39-46 ) Fs( 10-17 ) for microlites
	(Table 4.1). Clinopyroxene occurs only as microlites in basalt samples HA19 and
	HA31. The Mg-number of Cpx displays a limited range (72-85). Usually
	clinopyroxenes display normal zoning but some reverse-zoned clinopyroxene
	phenocrysts and microphenocrysts are present in HA20 and HA23b samples.

.1, we emphasize that the compositional range of olivine is Fo% ( 68-86 ) for phenocrysts and microphenocrysts, and Fo% ( 53-75 ) for microlites. The microlites of the oldest sample HA23b (Table

2

.4) show a restricted range Fo% ( 53-57 ). Generally, normal zoning with Fo-rich core olivines occur in all samples.

Clinopyroxene

Clinopyroxene (Cpx) usually occurs as needle-like microphenocrysts and microlites but the oldest sample HA23b exhibits clinopyroxene phenocrysts. All phenocrysts, microphenocrysts and microlites are diopside and augite in composition

(Figure 4.7)

. The composition of Cpx is Wo( 42-47 ), En( 41-47 ),Fs( 8-16 ) for

Table 4 . 2 :

 42 Calculated geothermometer and geobarometer values of Erciyes stratovolcano

  Two pyroxene geothermometer calculations can be applied only on the samples where two pyroxenes coexist in equilibrium conditions. From the literature, Ca content of high-Ca pyroxene decreases with increasing temperature, while the low-Ca phase increases. ER3 and ER22 are suitable for two pyroxene calculations(Figure 4.16). According to[START_REF] Putirka | Thermometers and Barometers for Volcanic Systems, Minerals, Inclusions and Volcanic Processes, Reviews in Mineralogy and Geochemistry[END_REF], based on the partitioning of enstatite + ferrosilite (=Fm2Si 2 O 6 = EnFs; FmO = FeO + MgO + MnO) between clinopyroxene and orthopyroxene increases precision for the available experimental data (Equation 36). A global regression (Eqn. 36) provides somewhat greater precision, but precision is improved further if the calibration data base is restricted to include only Mg-rich systems, in this case defined as those cpx-opx pairs where Mg# cpx > 0.75. The models perform best for mafic systems where Mg# cpx > 0.75. A separate regression using only experiments with Mg# cpx > 0.75 (Eqn 37). However, Erciyes basaltic samples Mg# cpx are > 0.75 (Appendix). Estimated two pyroxene geothermometers of ER3 and ER22 are 1035 o C and 1025 o C for Eq 36 and 1012 o C and 1022 o C for Eq37, respectively (Table 4.2)

	4.4.1.3. Clinopyroxene-Orthopyroxene Geothermometer
	.16, the phenocrysts of ER10 and ER26 are in
	equilibrium field. Due to that only these samples clinopyroxene-liquid pairs were
	calculated. The estimated temperatures are 1167 o C and 1138 o C, respectively
	(Table 4.2). The estimated depth of ER10 is 17 km and it is 10.5 km for ER26
	according to Putirka (2008) (Table 4.2).

Table 4 . 3 :

 43 liquid and clinopyroxene-liquid pairs. Differently from Erciyes Stratovolcano, none of the samples from Southwestern Cappadocia exhibit two pyroxenes. Estimated geothermometers of Southwestern Cappadocia are presented in Table 4.3. The evolution of temperatures according to changing host rock SiO 2 contents, are also presented in Figure 4.22. Calculated geothermometry and geobarometry values of Southwestern Cappadocia volcanics

Table 4 .

 4 3, both samples temperatures are very close to each other, 1262 o C for KA18 and 1263 o C for KA21. The details about the clinopyroxene-liquid geothermometer were presented in section 4.4.1.2. Estimated temperatures and pressures are listed in Table 4.3. Cpx geothermometer of the oldest and the less differentiated sample HA16 is 1233 o C. On the other hand more differentiated and the second youngest sample HA27 temperature is 1135 o C. The estimated barometer of HA16 is 7.79 kbar and its depth 28km. The estimated barometer values of HA27 are not rational, than it is not on the Table 4.3.

	4.4.2.2. Clinopyroxene-liquid geothermometer

 Hasandag stratovolcano

Mostly the cpx phenocrysts and microcrysts of Hasandag stratovolcano are out of the equilibrium field

(Figure 4.19)

. However, the samples HA19 and HA31 only have cpx microlites

(Figure 4.7)

due to that they are not used for thermometer calculations. HA20 is the only ideal sample for thermometer and barometer estimation. Cpx-liquid temperature of HA20 is 1208 o C and the cpx-liquid barometer is 4.66 kbar (Table

4

.3). According to

[START_REF] Putirka | Thermometers and Barometers for Volcanic Systems, Minerals, Inclusions and Volcanic Processes, Reviews in Mineralogy and Geochemistry[END_REF]

the depth of HA20 was estimated about 18km.

 Obruk-Zengen

Only the phenocrysts and microcrysts of HA16 and HA27 are under equilibrium conditions

(Figure 4.19)

. The samples HA14, HA15 and HA17 only have microlites and the phenocrysts and microcrysts of HA26 are not in equilibrium conditions

(Figure 4.19)

.

Table 4 . 4 :

 44 Estimated geothermometer and geobarometer values for the four groups volcanics.

Table 5 . 1 :

 51 Major element results and CIPW norm values of ES

		ER1	ER2	ER3	ER4	ER5	ER9	ER10 ER11 ER13	ER16	ER17	ER20	ER22	ER25	ER26	ER27	ER29	ER30	ER32
	Major element(%)
	SiO 2	54.34 55.33 53.13 62.02	60.25	57.34	53.09 56.70 48.89	62.70	55.46	54.53	57.37	57.15	56.43	55.01	52.45	55.07	56.22
	Al 2 O 3	17.17 17.32 16.52 16.67	16.19	17.64	16.95 17.65 17.06	16.38	17.57	17.56	18.24	17.57	17.98	17.42	17.68	17.40	17.78
	Fe 2 O 3	6.88	6.97	8.24	4.87	5.55	7.07	8.39	7.22 11.99	4.85	7.27	7.24	6.27	6.70	6.57	6.81	8.96	7.94	6.55
	MgO	6.10	5.62	6.54	3.00	4.06	4.21	6.65	4.04	5.44	2.86	4.95	5.88	4.67	4.59	4.59	5.62	4.78	4.84	5.12
	CaO	8.32	8.13	8.54	6.14	6.74	7.18	8.54	7.06	8.46	5.95	7.54	8.22	8.03	7.58	8.20	8.28	7.54	7.42	7.93
	Na 2 O	3.48	3.66	3.62	3.72	3.67	4.08	3.81	4.08	4.17	3.71	3.97	3.70	3.52	3.74	3.80	3.64	4.31	4.06	3.65
	K 2 O	1.24	1.37	1.02	1.67	1.63	1.23	0.96	1.24	0.94	1.74	1.54	1.36	1.10	1.18	1.31	1.14	1.65	1.62	0.95
	TiO 2	0.96	1.04	1.30	0.66	0.78	1.07	1.36	1.05	2.40	0.65	1.11	1.10	0.79	0.89	1.04	1.01	1.54	1.39	0.94
	MnO	0.11	0.11	0.13	0.08	0.09	0.12	0.13	0.12	0.18	0.08	0.12	0.12	0.10	0.11	0.11	0.11	0.15	0.13	0.10
	P 2 O 5	0.36	0.33	0.37	0.19	0.23	0.37	0.40	0.45	0.51	0.19	0.38	0.36	0.25	0.37	0.34	0.33	0.66	0.41	0.28
	LOI	0.23	0.28	-0.16	1.14	0.99	-0.19	-0.10	0.30 -0.32	1.09	0.30	0.29	0.47	0.50	0.08	0.42	0.15	0.50	0.58
	Mg#	69.06 66.99 66.61 61.59	65.60	60.78	66.60 59.28 53.29	61.38	63.17	67.13	66.00	64.08	63.72	67.27	58.18	61.34	66.31
	Total	99.19 100.15 99.25 100.15 100.19 100.12 100.18 99.91 99.73 100.22 100.20 100.36 100.81 100.39 100.42	99.79	99.87	100.79	100.09
	CIPW norm
	Q	3.04	3.54	0.86	16.40	12.75	7.13	-	6.89	-	17.56	3.09	1.85	8.33	7.85	5.46	3.94	-	2.49	6.62
	Or	7.43	8.17	6.13	9.99	9.78	7.28	5.71	7.40	5.63	10.42	9.14	8.10	6.50	7.03	7.74	6.81	9.82	9.62	5.66
	Ab	29.96 31.14 31.01 31.88	31.43	34.60	32.37 34.85 34.49	31.82	33.80	31.48	29.86	31.86	32.18	31.12	36.82	34.49	31.19
	An	27.99 26.97 26.14 24.21	23.17	26.27	26.39 26.43 25.26	23.16	25.76	27.42	30.74	27.83	28.20	28.11	24.28	24.53	29.64
	Ne	-	-	-	-	-	-	-	-	0.616	-	-	-	-	-	-	-	-	-	-
	Di	9.33	9.27	11.57	4.39	7.44	5.69	10.94	4.85 11.27	4.40	7.60	9.04	6.09	6.12	8.36	9.06	7.47	7.84	6.67
	Hy	17.40 15.98 18.37	9.71	11.47	13.68	17.60 13.97	-	9.04	15.34	16.92	14.23	14.40	13.28	16.11	9.48	14.66	15.74
	Ol	-	-	-	-	-	-	0.87	-	13.23	-	-	-	-	-	-	-	4.50	-	-
	Mt	2.15	2.16	2.57	1.71	1.95	2.46	2.60	2.53	3.73	1.89	2.25	2.24	2.18	2.34	2.03	2.14	3.14	2.77	2.04
	Il	1.86	1.99	2.50	1.27	1.50	2.04	2.59	2.02	4.60	1.26	2.13	2.11	1.50	1.71	1.97	1.94	2.95	2.64	1.80
	Ap	0.84	0.77	0.87	0.45	0.53	0.86	0.92	1.05	1.18	0.45	0.89	0.84	0.58	0.87	0.79	0.77	1.54	0.62	0.65

Table 5

 5

			.2: Trace element composition of Erciyes
		ER1	ER2	ER3	ER4	ER5	ER9	ER10 ER11 ER13 ER16 ER17 ER20 ER22 ER25 ER26 ER27 ER29 ER30 ER32
	Trace
	element
	(ppm)
	As	< L.D. < L.D. < L.D.	2.49	2.20	1.65	< L.D.	1.81	< L.D.	2.04	1.83	< L.D.	1.97	< L.D.	1.54	2.51	1.63	2.74	1.75
	Ba	343.65 331.22 260.93 314.00 339.60 317.80 225.70 355.70 228.20 351.20 347.90 296.30 260.60 317.40 292.10 246.90 519.50 413.30 252.30

  Chondrite normalized spider diagram, ER29, the youngest sample of LDDS is

				Less Differentiated Dated Samples (LDDS)
	1000												ER1
													ER3
													ER10
													ER13
	enriched in LREE and some trace elements present similar pattern with OIB (Figure 5.7a). ER13, the oldest sample in this group, is relatively more enriched in HREE than other samples and OIB. ER1 is the most depleted sample in HREE, 10 100 ER29 E-MORB Rock/Chondrite OIB
	and ER3 and ER10 present similar trends. All the samples, especially the youngest
	ones (ER9, ER11, ER17) of MDDS, are significantly enriched in LREE
	1 (Figure 5.7 b). The oldest ER32 sample displays more depletion in HREE. La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
	Eu/Eu* value varies between 0.90 and 1.04 in LDDS and 0.92-1.03 in MDDS
	10 100 1000 Rock/Chondrite			More Differentiated Dated Samples (MDDS)			ER9 ER11 ER17 ER20 ER22 ER26 ER27 ER30 ER32 ER2 ER25 E-MORB OIB
	1
	La	Ce	Pr	Nd	Sm	Eu	Gd	Tb	Dy	Ho	Er	Tm	Yb	Lu

group. According to

[START_REF] Zhu | Petrogenesis of volcanic rocks in the Sangxiu Formation, central segment of Tethyan Himalaya: A probable example of plume-lithosphere interaction[END_REF]

, if plagioclase separation is inefficient from the residual melts, plagioclase phenocrysts accumulation would be left as a residue in the melt. Therefore, more plagioclase in the rock gives higher Al 2 O 3 while the bulk rock has a lower Mg# and the absence of a negative Eu anomaly.

Table 5 . 3 :

 53 Selected trace elemet ratios of Erciyes

Table 5 . 4 :

 54 Major element analysis and CIPW normative values of Southwestern Cappadocia Volcanism

			Hasandağ stratovolcano				Obruk-Zengen				Karapınar
		HA13 b	HA18	HA19	HA20 HA23b HA31	HA14	HA15	HA16	HA17	HA26	HA27	KA18	KA19	KA21
	Major element(%)
	SiO 2	49.33	51.06	50.43	50.36	50.90	49.24	48.99	49.38	48.81	48.88	49.39	56.24	49.75	50.87	52.40
	Al 2 O 3	16.08	16.86	16.56	16.25	16.22	17.80	16.24	16.40	15.79	15.30	16.23	17.08	16.48	17.65	15.99
	Fe 2 O 3	8.88	8.72	8.87	9.14	8.86	9.57	9.01	9.42	8.97	8.60	9.39	7.31	8.53	9.17	8.20
	MgO	8.52	7.31	7.99	8.75	7.35	6.01	8.52	8.71	10.18	10.92	8.81	4.07	8.12	5.69	8.54
	CaO	9.78	8.76	9.42	9.85	9.32	10.68	9.28	8.98	10.43	10.86	9.47	7.57	11.02	9.52	9.11
	Na 2 O	3.44	3.86	3.64	3.64	3.68	3.70	3.65	3.71	3.43	3.00	3.73	4.19	3.36	3.96	3.50
	K 2 O	1.15	1.46	1.26	1.12	1.10	0.97	1.45	1.23	0.80	0.88	1.15	1.86	0.95	1.13	1.12
	TiO 2	1.19	1.43	1.33	1.21	1.23	1.34	1.40	1.50	1.10	1.06	1.49	1.25	1.03	1.27	1.00
	MnO	0.15	0.14	0.15	0.15	0.15	0.16	0.15	0.15	0.15	0.14	0.15	0.13	0.14	0.15	0.14
	P 2 O 5	0.44	0.43	0.44	0.43	0.37	0.38	0.43	0.41	0.37	0.25	0.41	0.31	0.30	0.35	0.33
	LOI	-0.14	-0.43	-0.58	-0.27	0.00	-0.06	-0.35	-0.28	-0.32	-0.23	0.22	0.24	-0.32	-0.38	0.12
	Mg#	69.16	67.82	67.79	69.11	65.98	59.50	70.41	68.37	72.62	74.80	68.68	59.19	68.99	60.97	72.38
	Total	98.72	99.88	99.72 100.64 98.97	99.51	98.69	99.32	99.75	99.83 100.42 100.23	99.35	99.38 100.43
	CIPW norm
	Q	-	-	-	-	-	-	-	-	-	-	-	3.518	-	-	-
	Or	6.92	8.70	7.49	6.63	6.619	5.77	8.71	7.33	4.76	5.24	6.837 11.051	5.67	6.76	6.64
	Ab	27.16	32.86	29.76	27.52 31.706 26.57	25.75	27.64	23.18	21.35 26.339 35.649	25.18	33.50	29.71
	An	25.49	24.53	25.29	24.66 24.932 29.41	24.03	24.69	25.51	25.90 24.282 22.426	27.37	27.31	24.69
	Ne	1.34	-	0.68	1.76	-	2.72	3.05	2.19	3.28	2.30	2.93	-	1.91	0.16	-
	Di	16.95	13.17	15.23	17.24 15.952 17.64	16.00	14.18	19.45	21.48 16.368 10.815	20.90	14.72	14.85
	Hy	-	0.11	-	-	2.164	-	-	-	-	-	-	10.878	-	-	10.76
	Ol	16.80	14.17	16.00	16.88	13.38	12.31	15.93	18.03	18.85	19.19 17.354	-	14.37	11.45	8.14
	Mt	2.00	2.71	1.98	2.02	1.995	2.14	2.82	2.10	2.00	1.92	2.088	2.552	1.91	2.86	2.53
	Il	2.30	2.74	2.54	2.30	2.378	2.57	2.70	2.88	2.10	2.03	2.847	2.387	1.98	2.43	1.91
	Ap	1.04	1.01	1.03	1.00	0.873	0.89	1.01	0.96	0.86	0.58	0.954	0.723	0.71	0.82	0.77

Table 5 . 5 :

 55 Trace element analysis of the Southwestern Cappadocia Volcanism

			Hasandağ stratovolcano				Obruk-Zengen				Karapınar
		HA13 b	HA18 HA19 HA20 HA23b HA31	HA14 HA15	HA16	HA17 HA26 HA27	KA18 KA19	KA21
	Trace
	element
	(ppm)
	As	< L.D.	< L.D. < L.D. < L.D. < L.D. < L.D.	< L.D. < L.D.	< L.D.	< L.D.	1.41	1.63	< L.D. < L.D.	< L.D.
	Ba	391.00	375.80 349.00 383.10 307.90 350.30	360.00 301.00 290.00 260.00 252.80 432.80	343.41 346.16 369.90
	Be	< L.D.	< L.D. < L.D. < L.D.	1.25	< L.D.	< L.D. < L.D.	< L.D.	< L.D.	1.37	1.55	< L.D. < L.D.	1.48
	Bi	< L.D.	< L.D. < L.D. < L.D. < L.D. < L.D.	< L.D. < L.D.	< L.D.	< L.D. < L.D. < L.D.	< L.D. < L.D.	< L.D.
	Cd	< L.D.	0.17	0.15	0.19	0.15	0.20	< L.D. < L.D.	< L.D.	< L.D.	0.20	0.15	< L.D. < L.D.	0.13
	Ce	61.56	53.92 54.06 58.90 48.59	53.74	66.02 50.26	49.87	35.80 48.21 50.64	56.34 56.15	56.03
	Co	< L.D.	33.36 35.42 38.05 35.24	32.99	< L.D. < L.D.	< L.D.	< L.D. 38.87 23.25	< L.D. < L.D.	33.44
	Cr	< L.D.	205.70 275.10 346.30 285.70 19.72	< L.D. < L.D.	< L.D.	< L.D. 295.70 43.51	< L.D. < L.D.	288.30
	Cs	< L.D.	0.45	0.24	0.45	0.14	0.53	< L.D. < L.D.	< L.D.	< L.D.	0.36	1.41	< L.D. < L.D.	0.98
	Cu	< L.D.	32.98 40.36 38.28 44.15	54.10	< L.D. < L.D.	< L.D.	< L.D. 37.15 38.24	< L.D. < L.D.	33.63
	Dy	4.27	4.27	4.41	4.35	4.51	4.42	4.47	4.14	3.74	3.39	4.35	4.11	3.84	4.46	3.50
	Er	2.42	2.33	2.45	2.38	2.55	2.49	2.38	2.23	2.17	1.91	2.44	2.36	2.19	2.57	2.01
	Eu	1.57	1.63	1.62	1.64	1.55	1.64	1.83	1.61	1.36	1.15	1.73	1.42	1.31	1.54	1.29
	Ga	< L.D.	17.95 17.71 17.96 18.15	19.65	< L.D. < L.D.	< L.D.	< L.D. 17.13 18.57	< L.D. < L.D.	15.48
	Gd	4.65	4.64	4.65	4.72	4.81	4.79	5.13	4.44	3.82	3.32	5.03	4.43	4.04	4.63	3.76
	Ge	< L.D.	1.25	1.41	1.36	1.37	1.25	< L.D. < L.D.	< L.D.	< L.D.	1.36	1.30	< L.D. < L.D.	1.36
	Hf	3.45	3.56	3.64	3.49	3.61	3.15	3.84	3.43	2.65	2.21	3.73	3.87	2.82	3.13	2.97
	Ho	0.86	0.82	0.85	0.85	0.90	0.87	0.90	0.83	0.79	0.69	0.85	0.82	0.79	0.95	0.70
	In	< L.D.	< L.D. < L.D. < L.D. < L.D. < L.D.	< L.D. < L.D.	< L.D.	< L.D. < L.D. < L.D.	< L.D. < L.D.	< L.D.
	La	31.02	28.30 27.73 31.01 23.99	28.14	31.46 24.20	25.94	18.07 22.50 25.75	29.92 28.31	29.72
	Lu	0.37	0.36	0.38	0.37	0.41	0.38	0.36	0.35	0.35	0.28	0.37	0.38	0.36	0.41	0.32
	Mo	< L.D.	1.02	0.62	0.77	0.90	0.72	< L.D. < L.D.	< L.D.	< L.D.	1.08	1.24	< L.D. < L.D.	0.90
	Nb	17.29	16.25 16.09 14.88 11.73	12.70	13.53 14.88	11.72	7.78	12.44 12.16	9.96	10.76	8.41
	Nd	26.67	25.32 25.60 26.83 23.39	24.80	31.85 23.73	21.37	16.96 25.64 22.93	22.97 25.20	23.48

Table 5

 5

	.5: (continued)
			Hasandağ stratovolcano				Obruk-Zengen				Karapınar
		HA13 b	HA18	HA19 HA20 HA23b HA31	HA14	HA15 HA16 HA17 HA26 HA27	KA18 KA19	KA21
	Trace element
	(ppm)
	Ni	< L.D.	127.90 145.30 177.40 129.50 48.51	< L.D. < L.D. < L.D. < L.D. 156.00 26.61	< L.D. < L.D. 135.10
	Pb	6.16	5.72	5.52	6.03	7.18	5.58	5.10	4.40	4.86	4.63	5.02	8.72	4.17	6.06	6.91
	Pr	6.84	6.43	6.54	6.89	5.39	6.41	7.73	5.83	5.47	4.09	5.64	5.41	6.06	6.29	6.39
	Rb	18.40	26.91	21.06	22.47	16.51	19.51	23.40	17.10	12.20	13.20	17.24	44.02	20.85	23.06	27.01
	Sb	< L.D.	< L.D. < L.D. < L.D. < L.D. < L.D.	< L.D. < L.D. < L.D. < L.D.	0.14	0.25	< L.D. < L.D.	< L.D.
	Sm	5.13	4.96	5.08	5.18	4.92	5.08	6.11	4.89	4.22	3.51	5.32	4.59	4.30	4.95	4.27
	Sn	< L.D.	1.35	1.34	1.27	1.01	1.19	< L.D. < L.D. < L.D. < L.D.	3.95	1.28	< L.D. < L.D.	1.20
	Sr	577.00	609.30 548.70 598.10 589.90 593.90	679.00 527.00 532.00 514.00 695.50 547.40	616.51 605.23 556.10
	Ta	0.99	1.25	1.23	1.06	0.79	0.89	0.78	0.88	0.59	0.43	0.93	0.98	0.52	0.59	0.65
	Tb	0.76	0.72	0.73	0.73	0.75	0.74	0.79	0.72	0.65	0.57	0.74	0.68	0.66	0.78	0.58
	Th	4.48	4.23	3.56	4.48	3.59	4.65	5.32	3.51	4.35	3.51	5.29	9.01	6.70	6.23	9.24
	Tm	0.35	0.35	0.37	0.36	0.38	0.37	0.36	0.33	0.33	0.28	0.35	0.35	0.32	0.40	0.29
	U	1.00	1.05	0.77	0.97	0.93	1.02	1.17	0.82	0.94	0.77	1.10	2.08	1.46	1.21	2.06
	V	< L.D.	160.90 169.30 180.00 172.30 221.20	< L.D. < L.D. < L.D. < L.D. 181.00 141.10	< L.D. < L.D. 153.40
	W	< L.D.	0.38	< L.D.	0.33	0.29	< L.D.	< L.D. < L.D. < L.D. < L.D.	0.32	0.70	< L.D. < L.D.	0.37
	Y	22.60	23.63	24.73	24.05	25.81	24.76	22.60	21.30	20.30	17.70	24.60	23.95	21.31	24.55	19.90
	Yb	2.35	2.32	2.42	2.33	2.59	2.45	2.32	2.18	2.19	1.85	2.35	2.41	2.23	2.62	2.02
	Zn	< L.D.	80.75	87.10	88.27	83.90	92.22	< L.D. < L.D. < L.D. < L.D. 93.15	67.66	< L.D. < L.D.	66.02
	Zr	167.00	167.80 173.40 159.30 156.50 134.80	186.00 166.00 126.00 97.00 164.00 162.40	134.34 141.82 116.60

Table 5 . 6 :

 56 Trace element ratios of the volcanics belonging to Southwestern Cappadocia Volcanism

	. REE diagrams compared to

low Zr/Nb, Zr/Ba and high Th/Y, Ta/Th and La/Nb ratios

(Table 5.6)

. Overall LREE values address the low-grade partial melting of the source can be related to an ancient subduction in the region.

123

Table 5

 5

	.7. 87 Sr/ 86 Sr

The Sr-Nd ratios of ES with the volcanics from different regions (Society Islands,

Table 5 . 7 :

 57 Age (ka), SiO 2 , isotope (Sr, Nd, Pb, O) values of ES

	Samples Groups	Age (ka)

SiO 2 εNd 87 Sr/ 86 Sr 143 Nd/ 144 Nd (206 Pb/ 204 Pb) 2sigma (207 Pb/ 204 Pb) 2sigma (208 Pb/ 204 Pb) 2sigma d18OWR

														2sigma
	ER 1	LDDS	93±11	54.34 0.28 0.705084 0.512652 18.8976 0.0008 15.6715 0.0010 39.0187 0.0033 6.89
	ER 2		-	55.33 -	-	-	-	-	-	-	-	-	-	-
	ER 3	LDDS	352±9	53.13 1.65 0.704537 0.512722 18.8756 0.0012 15.6551 0.0012 38.9547 0.0033 6.82
	ER4		-	62.02 -	-	-	-	-	-	-	-	-	-	-
	ER5		-	60.25 -	-	-	-	-	-	-	-	-	-	-
	ER9	MDDS	< 1 (TU-ER -23)	57.34 1.41 0.704511 0.512710 18.9158 0.0008 15.6626 0.0008 39.0074 0.0023 6.51
	ER10	LDDS	297±15	53.09 1.78 0.704587 0.512729 18.8962 0.0008 15.6662 0.0008 38.9897 0.0025 6.46
	ER11	MDDS	<1	56.70 1.14 0.704710 0.512696 18.9201 0.0010 15.6808 0.0009 39.0520 0.0032 6.37
	ER13	LDDS	1695±37	48.89 4.63 0.703609 0.512875 18.9497 0.0014 15.6458 0.0013 38.9330 0.0036 6.05
	ER16		-	62.70 -	-	-	-	-	-	-	-	-	-	-
	ER17	MDDS	45±5	55.46 1.13 0.704534 0.512696 18.8966 0.0016 15.6726 0.0015 39.0013 0.0039 6.79
	ER20	MDDS	115±7	54.53 1.02 0.704697 0.512690 18.8926 0.0009 15.6723 0.0009 39.0055 0.0027 6.80
	ER22	MDDS	40±7	57.37 0.95 0.704769 0.512686 18.9133 0.0010 15.6835 0.0009 39.0562 0.0027 6.47
	ER25		-	57.15 -	-	-	-	-	-	-	-	-	-	-
	ER26	MDDS 25±8 (

TU-ER-45) 56.43 0.93 0.704875 0.512685 18.8979 0.0012 15.6745 0.0011 39.0206 0.0037 6.51 ER27(1) MDDS - 55.01 1.10 0.704796 0.512695 18.8930 0.0020 15.6725 0.0016 39.0139 0.0041 6.15 ER27(2) MDDS - 55.01 1.13 0.704817 0.512696 18.8931 0.0022 15.6723 0.0021 39.0126 0.0052 6.15 ER29 LDDS 13±5 52.45 0.63 0.704876 0.512670 18.9099 0.0014 15.6850 0.0014 39.0548 0.0044 6.63 ER30 MDDS 102±6.6 (TU-ER-30) 55.07 1.57 0.704509 0.512718 18.9452 0.0008 15.6641 0.0009 39.0371 0.0028 7.12 ER32 MDDS 707±20 56.22 1.19 0.704557 0.512699 18.9022 0.0019 15.6748 0.0015 39.0246 0.0044 6.00

  Table 5.7). The youngest samples ER9 and ER11, which have slightly different 87 Sr/ 86 Sr ratios and 143 Nd/ 144 Nd ratios from each other,

respectively

(Table 5.7;

.

Table 5 . 8 :

 58 Age(ka),SiO2, isotope (Sr, Nd, Pb, O) and trace elements of Southwestern Cappadocia Volcanism

	Samples Groups	Age (ka)	SiO 2 εNd	87 Sr/	86 Sr	143 Nd/	144 Nd	(206 Pb/	204 Pb) 2sigma	(207 Pb/	204 Pb)	2sigma	(208 Pb/	204 Pb) 2sigma d18OWR
	HA13b	HS	19±5	49.33 0.83 0.704952	0.512680	18.8997	0.0011	15.6704	0.0010	39.0109	0.0028	6.79
	HA14	OZ	395±10	48.99 3.15 0.704333	0.512799	18.8602	0.0018	15.6411	0.0018	38.8905	0.0054	6.57
	HA15	OZ	404±10	49.38 2.75 0.704319	0.512779	18.8800	0.0014	15.6557	0.0014	38.9507	0.0041	6.58
	HA16	OZ	799±20	48.81 1.67 0.704711	0.512723	18.8913	0.0013	15.6567	0.0013	38.9699	0.0037	6.61
	HA17	OZ	66±7	48.88 2.14 0.704472	0.512748	18.9134	0.0019	15.6536	0.0016	38.9799	0.0041	6.38
	HA18	HS	105±5	51.06 1.57 0.704636	0.512718	18.8762	0.0014	15.6587	0.0015	38.9619	0.0046	6.73
	HA19	HS	79±4	50.43 1.32 0.704729	0.512705	18.8871	0.0012	15.6568	0.0012	38.9646	0.0034	6.62
	HA20	HS	57±5	50.36 0.38 0.704908	0.512657	18.8967	0.0014	15.6649	0.0018	38.9932	0.0043	6.63
	HA23b	HS	543±12	50.69 1.47 0.704625	0.512714	-	-	-	-	-	-	6.92
	HA26	OZ	675±16	49.39 3.67 0.704153	0.512826	18.8791	0.0015	15.6422	0.0021	38.9070	0.0041	5.88
	HA27	OZ	331±7	56.24 1.74 0.704542	0.512727	18.9040	0.0021	15.6614	0.0017	38.9858	0.0050	7.27
	HA31	HS	2±7	49.24 0.67 0.704976	0.512672	18.8979	0.0015	15.6598	0.0017	38.9910	0.0045	6.68
	KA18	K	280±7.1 (CK89-19)	49.75 -0.18 0.705320	0.512629	18.9795	0.0011	15.6857	0.0009	39.1376	0.0027	6.75
	KA19	K	<1	50.87 -0.10 0.705188	0.512633	18.9739	0.0016	15.6851	0.0015	39.1338	0.0038	6.59
	KA21	K	163±10	52.40 -0.69 0.705502	0.512602	18.9960	0.0009	15.6976	0.0009	39.1868	0.0029	6.31

Table 5

 5

.8) In HS samples,

206

Pb/ 204 Pb, 207 Pb/ 204 Pb, 208 Pb/ 204 Pb isotope ratios vary in between (18.88-18.90);

(15.66-15.67); (38.96-39

.01) (Table

  ER17 and ER22) have slightly different 87 Sr/ 86 Sr ratios, and 143 Nd/ 144 Nd ratios from each other,(Table 5.7;. Samples of the ES are plotted in Enriched Mantle (EMII) area which is above the Northern Hemisphere Reference Line (NHRL) (Figure5.17). In LDDS group, except ER13 from oldest sample to the youngest one, positive trend has seen in 206 Pb/ 204 Pb isotope ratio (Figure 5.20). Moreover, by the younger ages in MDDS except sample ER32, 206 Pb/ 204 Pb ratio increases as seen in 87 Sr/ 86 Sr vs. Age (ka) (Figure 5.15). No significant correlation is observed in LDDS group, δ 18 O vs. 87 Sr/ 86 Sr diagram of the ES samples display co-variation, however it is clearly noted that LDDS group samples tend positive correlation against Sr-isotopes and SiO 2 variation.

	20. According to the Age vs. Sr-Nd isotope diagrams, slightly different trends are
		seen between LDDS and MDDS groups (Figure 5.15). LDDS age interval is
		more extended than MDDS (Table 5.7). Sr-Nd isotopes vs. Age relations are
		more systematic in LDDS than MDDS.
	21. According to the age, Sr-Nd vs. SiO 2 diagrams (Figure5.16), slightly different
		trends are seen between LDDS and MDDS groups like their major element
		values.
	22. 24.	206 Pb/ 204 Pb vs. SiO 2 diagram, negative Pb isotope correlation in LDDS and
		positive correlation in MDDS are observed. The correlation is not regular in
		contrast to the age data of the ES samples. Especially, positive correlation of Pb-
		isotopes vs. differentiation in the MDDS group is likely pointing out crustal
		contamination took place during the formation of the magma.
		In MDDS group, the similar age samples disperse in terms of δ 18 O‰ and
		present slightly negative correlation in contrast to Sr-isotopes and SiO 2 (Figure
		5.23b). 206 Pb/ 204 Pb isotope ratio increases with δ 18 O‰ decrease in LDDS group
		and in MDDS group, possible positive tendency is seen between O-Pb isotopes
		(Figure 5.24).

19.

In LDDS, except the oldest sample (ER13), Sr-isotopes are increasing, and the Nd-isotopes are decreasing by younger volcanism (Figure

5

.15a-c). In MDDS, there isn't any systematic Sr vs. Nd isotopes. The young samples (ER9, ER11,

23.

25.

  pmm,87 Sr/ 86 Sr=0.703384, 143 Nd/ 144 Nd=0.512920;[START_REF] Kürkçüoğlu | Erciyes stratovolkanı'nın Jeokimyasal Evrimi, Doktora Tezi[END_REF], bmg-1 (Sr=183 ppm, Nd=35.3 ppm, 87 Sr/ 86 Sr=0.717924, 143 Nd/ 144 Nd=0.512139; [181], and N26 (Sr=911 ppm, Nd=60.12 ppm, 87 Sr/ 86 Sr=0.70804, 143 Nd/ 144 Nd =0.51227;İlbeyli, 2004).

Table 6 . 4 :

 64 Olivine, orthopyroxene, clinopyroxene and plagioclase fractionation values of Southwestern Cappadocia volcanics.

	Less		More	Olivine	Clinopyroxene	Plagioclase %
	Differentiated		Differentiated	%	%
	Samples		Samples
	HA20		HA18	3.3	6.34	4.95
	HA23b		HA18	-	4.04	0.67
	HA13b		HA19	2.35	-	2.31
	HA20		HA23b	3.01	2.27	2.44
	HA20		HA19	2.25	-	0.95
	HA19		HA18	1.72	3.79	3.66
	HA16		HA26	4.28	6.35	6.89
	HA17		HA26	5.84	11.56	8.27
	KA18		KA19	4.3	12.05	9.33
	6.2.3. Crustal Contamination-AFC
	All of Southwestern Cappadocia volcanics have higher LILE (Figure 5.12) and LREE

(Figure

5

.13) content in comparison to HFSEs vs. HREEs. LILE and LREE enrichment can be explained with magmatic differentiation processes such as subduction-related processes or crustal contamination, or the tendency of LILEs and

  . If mantle was enriched by subduction and/or crustal contamination elements, Th/Y is expected to be greater than Nb/Y. However, if the mantle was enriched by an earlier and weak partial melting, it could exhibit withinplate enrichment trends with high Th/Y and Nb/Y ratios. Accordingly, high Th/Y and Nb/Y ratios in HS and OZ samples are indicative of within-plate enrichment,

	whereas Th/Y increasing Th/Y vs. low Nb/Y in K suggests mainly subduction
	enrichment. As in Figure 6.12, Southwestern Cappadocia volcanics have a mainly
	lithospheric	mantle	source	and/or	plotted	in	areas	with
	lithospheric + asthenospheric interaction. A comparison of Southwestern

  15-0.35), (0.22-0.31) and (3.56-4.65), (3.51-9.01), (6.23-9.24), respectively. Th/Ce ranges were (0.07-0.09), (0.07-0.18) and (0.11-0.16); while 87 Sr/ 86 Sr ranges were (0.704734-0.704981), (0.704153-0.704711) and (0.705188-0.705502); and 206 Pb/ 204 Pb ranges were (18.88-18.90), (18.86-18.91) and (18.97-19.00); respectively, for HS, OZ and K. Whereas their 143 Nd/ 144 Nd isotope values and Ba/La ratios range between (0.512679-0.512740), (0.512723-0.512826), (0.512602-0.512633) and(12.35-13.28), (11.18-16.81) and (11.48-12.45);

	respectively.

Table 6 . 5 :

 65 Erciyes stratovolcano and Southwestern Cappadocia (HS, OZ and K) trace element ratios and Sr, Nd, Pb isotope values .704537 0.704511 0.704587 0.704710 0.703609 0.704534 0.704697 0.704769 0.704875 0.704796 0.704817 0.704876 0.704509 0.704557 143 Nd/ 144 Nd 0.512652 0.512722 0.512710 0.512729 0.512696 0.512875 0.512696 0.512690 0.512686 0.512685 0.512695 0.512696 0.512670 0.512718 0.512699

	Erciyes stratovolcano

  Table 2.3; Table 2.4). In Chapter 5, the incompatibility particularly between trace element and isotope data for HS, OZ and K indicate a spatial grouping rather than temporal in Central Anatolia. Table 5.7 and Table 5.8 reveal that the products from these four regions with similar multielement and spidergram patterns (Figure. 6.18) but different isotope values have undergone different magmatic processes.

Figure 5.10: (continued)

ACKNOWLEDGEMENTS

I would like to thank TUBITAK (The Scientific and Technological Research Council of Turkey) for financial support during my research, Research Project No: 109Y064.

Pb-isotope ratios are known as fingerprints of crustal contamination [START_REF] Ellam | Oxygen isotope constrains on the crustal contribution to the subduction-related magmatism of the Aeolian Islands, southern Italy[END_REF] as O-isotopes. Especially, positive correlation of Pb-isotopes vs. differentiation in the MDDS group is likely pointing out crustal contamination took place during the formation of the magma. In some special cases, such as tracing the sub-levels of the upper mantle (e.g. Sub-Continental Lithosphere) with Sm/Nd and Pd-isotopic systems are not the most effective isotopic fingerprints. To discuss the details of the source, additional tracers as O-stable isotope systematic are needed. Therefore, isotope results are also combined and compared with O-isotopes (WR). δ 18 O distributions of the ES is given in (Table 5.7). δ 18 O values of the LDDS vary range about +6.05-6.89‰ and +6.00-7.12‰ for MDDS (Table 5.7). The highest δ 18 O value (7.1‰) is seen in the sample ER30 indicating a possible alteration observed in thin sections (Table 3.1) and higher LOI values support this as well (Table 5.1). determined as end members and the element contents of these samples were assumed to represent the original liquid given in Equation 2 (Table 6.1).

Fractionation degrees of plagioclase, clinopyroxene and olivine were calculated in percentages (Table 6.2). Generally, with cooling and crystallization of magma, Mg# decreases [START_REF] Zhu | Petrogenesis of volcanic rocks in the Sangxiu Formation, central segment of Tethyan Himalaya: A probable example of plume-lithosphere interaction[END_REF].

Crustal Contamination and AFC (Assimilation Fractional Crystallization)

Enrichment in LILE and LREE elements can be explained with subduction contributions, crustal contamination or low degree partial melting [START_REF] Pearce | Genesis of collision volcanism in Eastern Anatolia, Turkey[END_REF]. Multi element diagrams of Erciyes volcanics show LILE and LREE enrichment. This is indicative of magmatic differentiation (subduction, crustal contamination, etc.) or the tendency of LILEs and LREEs to shift into liquid phase during partial melting.

In previous sections, it was demonstrated that fractional crystallization and partial melting was effective. Herein, the modeling of the effect of crustal contamination is proposed. 6.3).

According to [START_REF] Frey | Integrated models of basalt petrogenesis study of quartz tholeiited to olivine melilities from south eastern Australia Utilizing geochemical and experimental petrological data[END_REF], Mg# values between Mg#>68-70 are values for primary magmas. The fact that many samples have similar Mg# values leads us to think that the effect of fractionation was limited and/or negligible for some samples.

Tuzgölü Fault Zone (TGFZ)

The Tuzgölü Fault is 135 km long and one of the most important faults in the Tuz Gölü Basin. The Tuzgölü Fault is N30-40W oriented and SW and NE dipping fault plane (Erman et al., 2013).

Similar to the EFZ (Ecemiş Fault Zone), TGFZ also comprises parallel segments.

The The research data indicate that the effect of subduction in Central Anatolia decreased from the Miocene to the Quaternary, and the Quaternary samples mainly had a sediment input trend than a slab-derived fluids trend (Figure 6.17d).

Table 6.5: Geochemical summary of the studied volcanic centers in Central Anatolia.

Study