Yves Gallet

Miquel Molist Montaña

Agnès Genevey

Xavier Clop García

Erwan Thébault

Anna Gómez Bach

Maxime Le Goff

Béatrice Robert

Inga Nachasova

New Late Neolithic (c.7000-5000 BC) archeointensity data from Syria. Reconstructing 9000 years of archeomagnetic field intensity variations in the Middle East

Keywords: Archeomagnetism, Geomagnetic field intensity, Neolithic, Halaf, Middle East, Holocene

We present new archeomagnetic intensity data from two Late Neolithic archeological sites (Tell Halula and Tell Masaïkh) in Syria. These data, from 24 groups of potsherds encompassing 15 different time levels, are obtained using the Triaxe experimental protocol, which takes into account both the thermoremanent magnetization anisotropy and cooling rate effects on intensity determinations. They allow us to recover the geomagnetic intensity variations in the Middle East, between ~7000 BC and ~5000 BC, i.e. during the so-called pre-Halaf, proto-Halaf, Halaf and Halaf-Ubaid Transitional cultural phases. The data are compared with previous archeointensity results of similar ages from Northern Iraq (Yarim Tepe II and Tell Sotto) and Bulgaria. We find that previous dating of the Iraqi material was in error. When corrected, all northern Mesopotamian data show a relatively good consistency and also reasonably match with the Bulgarian archeointensity dataset. Using a compilation of available data, we construct a geomagnetic field intensity variation curve for the Middle East encompassing the past 9000 years, which makes it presently the longest known regional archeomagnetic intensity record. We further use this compilation to constrain variations ACCEPTED MANUSCRIPT 2 in dipole field moment over most of the Holocene. In particular, we discuss the possibility that a significant dipole moment maximum occurred during the third millennium BC, which cannot easily be identified in available time-varying global geomagnetic field reconstructions.

Introduction

Recent studies have been focused on the construction of time-varying global archeomagnetic field models that cover most of the Holocene (e.g. [START_REF] Korte | Reconstructing the Holocene geomagnetic field[END_REF][START_REF] Nilsson | Reconstructing Holocene geomagnetic field variation: New methods, models and implications[END_REF][START_REF] Pavón-Carrasco | A geomagnetic field model for the Holocene based on archaeomagnetic and lava flow data[END_REF]. These models have been developed

with the aim to decipher core dynamics over centennial and millennial time scales, the evolution of the past solar activity and the interactions between geomagnetic field and external processes (e.g. [START_REF] Korte | Geomagnetic field for 0-3 ka: 2. A new series of time-varying global models[END_REF][START_REF] Licht | Ensembles of low degree archeomagnetic field models for the past three millennia[END_REF][START_REF] Usoskin | Evidence for distinct modes of solar activity[END_REF]. In all these studies, however, the authors acknowledge the fact that for the more ancient periods, i.e. beyond the first millennium BC, the reliability and accuracy of the geomagnetic field models are strongly penalized by the low number and the poor temporal and geographical distributions of the available archeomagnetic and volcanic paleomagnetic data. To overcome this problem, often paleomagnetic data from sediments have been included in the models reference dataset; nevertheless sedimentary data do not significantly improve the accuracy of the models because a part of them, difficult to estimate, may be biased by experimental errors and/or because these data often lack precise dating (e.g. [START_REF] Valet | Secular variation of the geomagnetic dipole during the past 2000 years[END_REF][START_REF] Nilsson | Holocene geocentric dipole tilt model constrained by sedimentary paleomagnetic data[END_REF]. There is therefore a critical need for new well dated archeomagnetic data dated with ages older than the first millennium BC.

The Middle East, thanks to its rich archeological and historical heritage, offers the possibility to travel back through the geomagnetic field history over most of the Holocene, recovering what could be the longest known archeomagnetic field record.

Archeomagnetic studies conducted up to now were mainly focused on the Bronze and Iron Age archeological periods, allowing a better characterization of the regional geomagnetic field intensity behavior for the last 3 millennia BC (i.e. [START_REF] Genevey | Eight thousand years of geomagnetic field intensity variations in the eastern Mediterranean[END_REF]Gallet and Le Goff, 2006;[START_REF] Gallet | Geomagnetic field intensity behavior in the Middle East between 3000 BC and 1500 BC[END_REF]Gallet et al., , 2014;;[START_REF] Ben-Yosef | Application of copper slag in geomagnetic archaeointensity research[END_REF][START_REF] Robert | Production céramique et représentations animales à l'époque de Halaf[END_REF][START_REF] Gallet | Archéomagnétisme à Mishirfeh-Qatna: Nouvelles données sur l'évolution de l'intensité du champ magnétique terrestre au Moyen-Orient durant les derniers millénaires[END_REF][START_REF] Thébault | A bootstrap algorithm for deriving the archeomagnetic field intensity variation curve in the Middle East over the past 4 millennia BC[END_REF][START_REF] Shaar | Geomagnetic field intensity: How high can it get? How fast can it change? Constraints from Iron-Age copper-slag[END_REF][START_REF] Ertepinar | Archaeomagnetic study of five mounds from Upper Mesopotamia between 2500 and 700 BC: further evidence for an extremely strong geomagnetic field ca. 3000 years ago[END_REF][START_REF] Gallet | Archaeological and geomagnetic implications of new archaeomagnetic intensity data from the Early Bronze high terrace "Massif Rouge" at Mari (Tell Hariri, Syria)[END_REF]. These studies have revealed significant field intensity ACCEPTED MANUSCRIPT 3 variations, and in particular a series of intensity maxima between ~2600 and 2500 BC, between ~2300-2000 BC, around 1500 BC and at the very beginning of the first millennium BC (e.g. Gallet et al., 2014). These studies have further shown that the beginning of the first millennium BC was most probably marked by the highest geomagnetic field intensity so far detected during the Holocene and perhaps even before [START_REF] Ben-Yosef | Geomagnetic intensity spike recorded in high resolution slag deposit in southern Jordan[END_REF][START_REF] Shaar | Geomagnetic field intensity: How high can it get? How fast can it change? Constraints from Iron-Age copper-slag[END_REF][START_REF] Ertepinar | Archaeomagnetic study of five mounds from Upper Mesopotamia between 2500 and 700 BC: further evidence for an extremely strong geomagnetic field ca. 3000 years ago[END_REF][START_REF] Livermore | Core-flow constraints on extreme archeomagnetic intensity changes[END_REF].

In contrast, for older periods between ~7000 BC and 3000 BC, i.e. during the Late Neolithic (or Pottery Neolithic) and the Chalcolithic, the archeointensity data from the Middle East remain relatively scarce, which prevents an accurate description of the regional geomagnetic field intensity variations (e.g. [START_REF] Genevey | Eight thousand years of geomagnetic field intensity variations in the eastern Mediterranean[END_REF][START_REF] Ben-Yosef | Application of copper slag in geomagnetic archaeointensity research[END_REF]. However, several possibilities exist to sample pre-Bronze Age archeological sites. This is particularly true for the 6th millennium BC, which saw the development of the Halaf culture throughout the northern Mesopotamian region. This culture was named after the Tell Halaf archeological site in northern Syria (Fig. 1a), which was discovered and first excavated by the German diplomat Max von Oppenheim at the beginning of the 20th century. The Halaf culture is notably characterized by a plentiful pottery production presenting a fine and light-colored clay paste, with brown or black monochrome or polychromatic painted decorations (e.g. [START_REF] Akkermans | The archaeology of Syria. From complex hunter-gatherers to early urban societies[END_REF]Nieuwenhuyse et al., 2013 and references therein). This well-fired ceramic production thus constitutes a promising target for archeointensity investigations.

Going further back in time, archeomagnetic studies may benefit from recent archeological studies conducted in Syria that focused on the 7th millennium BC, which saw the emergence of the first pottery production in the Near East (e.g. [START_REF] Tsuneki | The earliest pottery sequence of the Levant: New data from Tell el-Kerkh 2, Northern Syria[END_REF][START_REF] Le Mière | Les débuts de la céramique du Proche-Orient[END_REF][START_REF] Nishiaki | The oldest pottery Neolithic of Upper Mesopotamia: New evidence from Tell Seker al-Aheimar, the Khabur, northeast Syria[END_REF][START_REF] Molist | Tell Halula (vallée de l'Euphrate, Syrie): nouvelles données sur les occupations Néolithiques[END_REF][START_REF] Nieuwenhuyse | Not so coarse, nor always plain -the earliest pottery of Syria[END_REF][START_REF] Nieuwenhuyse | Interpreting the Late Neolithic of Upper Mesopotamia[END_REF]. At first rare, the pottery was sometimes of a surprisingly elaborated conception with a painted decoration during a primitive phase referred to as the "Initial Pottery Neolithic" (∼7000-6700 BC; e.g. [START_REF] Van Der Plicht | Tell Sabi Abyad, Syria: radiocarbon chronology, cultural change, and the 8.2 ka event[END_REF]. By the middle of the 7th millennium BC, the use of ceramics spread over northern Mesopotamia (Nieuwenhuyse et al., 2010, 2013 andreferences therein). This pre-Halaf period is mainly represented by undecorated plant-tempered pottery with a coarse clay paste shaped into baskets. The fineness of the clay paste improved at the end of the 7th millennium BC during a period referred to as proto-Halaf (∼6050-5900 BC), just preceding the Halaf period, with the use of mineral-tempered clay (e.g. [START_REF] Cruells | The proto-Halaf period in Syria. New sites, new data[END_REF]. According to Akkermans and Schwarz (2003), the pre-Halaf coarse pottery was produced in open fires, with heating temperatures of about 700-750°C, while the elaborate Halaf ceramics were most probably heated at higher temperatures in chambered kilns. For the pre-and proto-Halaf periods encompassing the 7th millennium BC, archeointensity studies are thus still possible, but they may be further complicated by the characteristics of the ceramic production.

To extend the Syrian geomagnetic field intensity record, which presently mainly documents the Bronze and Iron Age periods, we conducted an archeomagnetic study on the pre-Halaf, proto-Halaf, Halaf and Halaf-Ubaid Transitional archeological periods, a time interval of nearly two millennia (∼7000 to ∼5000 BC) covering the Pottery Neolithic, at the end of the Neolithic (e.g. [START_REF] Campbell | Rethinking Halaf chronology[END_REF][START_REF] Campbell | Beyond the Ubaid: Transformation and integration in the late prehistoric societies of the Middle East[END_REF][START_REF] Van Der Plicht | Tell Sabi Abyad, Syria: radiocarbon chronology, cultural change, and the 8.2 ka event[END_REF]Nieuwenhuyse et al., 2013 and references therein). The new archeointensity data reported in this study were mostly obtained from potsherds collected from the archeological site of Tell Halula located in northern Syria (Fig. 1a).

These results were complemented by few data obtained from potsherds discovered at the archeological site of Tell Masaïkh, located south-east along the middle course of the Euphrates river (Fig. 1a). It is of interest to note that the longest and almost continuous regional archeointensity record presently available was obtained from Bulgaria [START_REF] Kovacheva | Extended and revised archaeomagnetic database and secular variation curves from Bulgaria for the last eight millennia[END_REF]. It begins around 6000 BC, i.e. a date during the proto-Halaf period, which means that some of the new data presented in this study are the oldest archeointensity data recovered until now. Furthermore, we recall the recent effort of data compilation of archeomagnetic, volcanic and sedimentary paleomagnetic results that led to the construction of global archeomagnetic field models encompassing almost the entire Holocene [START_REF] Korte | Reconstructing the Holocene geomagnetic field[END_REF][START_REF] Nilsson | Reconstructing Holocene geomagnetic field variation: New methods, models and implications[END_REF][START_REF] Pavón-Carrasco | A geomagnetic field model for the Holocene based on archaeomagnetic and lava flow data[END_REF].

Any new archeomagnetic intensity data dated to the Late Neolithic-Early Chalcolithic period, now rather rare (e.g. [START_REF] Genevey | ArcheoInt: An upgraded compilation of geomagnetic field intensity data for the past ten millennia and its application to the recovery of the past dipole moment[END_REF][START_REF] Knudsen | Variations in geomagnetic dipole moment during the Holocene and the past 50 kyr[END_REF], will therefore allow us to test, at least regionally, the accuracy of the available models and in return will better constrain these models. This point is particularly critical and we will also report in this study on erroneous dating of a relatively large archeointensity dataset previously obtained in the Middle East for the 7 th and 6 th millennia BC (Nachasova andBurakov, 1995, 1998).

Archeomagnetic sampling

Tell Halula

Tell Halula (λ=36°25'N, φ=38°10'E) is located in the modern Syrian administrative province of Raqqa, about 80 km west of the city of Raqqa and 85 km east of the city of Aleppo. This archeological site, ~4 km west of the Euphrates, forms a subcircular artificial mound (360 m x 300 m), with an archeological deposit thickness of ~14 m (Fig. 1b). Archeological excavations conducted since 1991 by a team of the Universitat Autónoma de Barcelona revealed a total of 38 phases of occupation. From the stratigraphic and archeological constraints (including chipped stone artefacts, pottery typology, figurines and architecture), it has been determined that the site was occupied continuously from the Middle Pre-Pottery Neolithic B (PPNB) to the Late Halaf periods, i.e. from ~7800 to 5300 cal BC [START_REF] Molist | Tell Halula (vallée de l'Euphrate, Syrie): nouvelles données sur les occupations Néolithiques[END_REF][START_REF] Molist | Tell Halula (Euphrates Valley, Syria): New approach to VII and VI millennia cal. B.C. in Northern Levant framework[END_REF][START_REF] Molist | Tell Halula (Siria). Un yacimiento neolítico del valle medio del Éufrates. Campañas de 1991 y 1992[END_REF][START_REF] Molist | Halula, village néolithique en Syrie du Nord, in Communautés villageoises du Proche-Orient à l'Atlantique[END_REF]. 2, 7, 14, 30, 44 and 45). The Neolithic ceramic horizon encompasses most of the seventh millennium BC and part of the sixth millennium BC (Architectural Phases 20 to 38), spanning the pre-Halaf (or Period 5 according to Lyon's School terminology; [START_REF] Hours | Atlas des sites du Proche-Orient (14000-5700 BP)[END_REF], the proto-Halaf or Halaf Transitional and the Halaf (Early, Middle, Late) periods.

The archeological and stratigraphic data indicate the presence of a sedentary population, with several large houses or architectural structures relatively dispersed over a surface of ~6 ha, i.e. with large open areas between households and buildings for domestic use. Furthermore, several structures for a collective use were discovered for the pre-Halaf period, with a massive enclosing wall in Sector 1 and a drainage channel in Sector SS7 [START_REF] Molist | Tell Halula (Siria). Un yacimiento neolítico del valle medio del Éufrates. Campañas de 1991 y 1992[END_REF][START_REF] Molist | Espace collectif et domestique dans le néolithique des IXème et VIIIème millénaires B.P. au nord de la Syrie: apports du site de Tell Halula (Vallée de l'Euphrate)[END_REF][START_REF] Molist | Tell Halula: Un village des premiers agriculteurs-éleveurs dans la Vallée de l'Euphrate[END_REF][START_REF] Molist | Tell Halula (Euphrates Valley, Syria): New approach to VII and VI millennia cal. B.C. in Northern Levant framework[END_REF].

The pottery assemblages analyzed in the present study were sampled following the main chronocultural phases documented at Tell Halula (Fig. 2; see description in Molist et al., 2013 and Supplementary Text1). Here, we used the same chronological time scale as in [START_REF] Molist | Tell Halula (Euphrates Valley, Syria): New approach to VII and VI millennia cal. B.C. in Northern Levant framework[END_REF]. For the first pottery production within the Early Pre-Halaf (Ceramic Phase I; ~7000-6600 BC), two groups of fragments collected from the top of Sector 2 were analyzed. The first group of fragments (SY 127) was recovered from a pit located in an open area and the second (SY 125), a little younger than the previous one, was collected from an occupation level associated with a rectangular building. For the intermediate pre-Halaf period (Ceramic Phase II; ~6600-6300 BC), three pottery groups were collected from a large outdoor space between several domestic units. Their Nine groups of fragments were collected from the most recent chronological phases at Tell Halula dated in the Late Halaf (Ceramic Phase VII; ~5550-5300 BC). This relatively dense sampling was possible due to a relatively complete stratigraphic sequence from Sector 49 [START_REF] Gómez | Caracterización del producto cerámico en las comunidades neolíticas de mediados del VI milenio cal BC: el valle del Éufrates y el valle del Khabur en el Halaf Final[END_REF]. For most of these groups, the fragments were recovered from different pits excavated in a large open yard, that were used for the disposal of ash and domestic waste. The stratigraphic data and the ceramic typology distinguish five successive temporal intervals, each being documented by one or several pottery groups (from older to younger: SY86-131; SY135; SY84 and SY138; SY82 and SY83-136; SY80, SY81 and SY132).

In summary, 22 different pottery groups from 14 successive occupation levels were thus sampled at Tell Halula, whose dates span ~1700 years, between ~7000 and ~5300 BC. For displaying the results in a relative chronological framework for phases II and VII, we made the rough approximation of an equi-temporal distribution for respectively the three and five successive occupation levels (i.e. assuming a duration of ACCEPTED MANUSCRIPT 7 100 years for each intermediate pre-Halaf level between 6600 BC and 6300 BC and a duration of 50 years for each Late Halaf level between 5550 BC and 5300 BC; dating with * in Table 1). Ware known as Dalma types and Ubaid-style ceramics (Masetti-Rouault, 2005;[START_REF] Robert | Characterizing the Halaf-Ubaid Transitional Period by Studying Ceramic from Tell Masaı kh, Syria. Archaeological Data and Archaeometry Investigations[END_REF][START_REF] Robert | Développement et disparition de la production céramique halafienne: implications techniques et sociales à partir d'études de cas[END_REF]. We sampled in Locus K171 two groups of these fragments with fine mineral-tempered clay paste (pottery groups SY37, SY38), the first in the occupation layer referred to as E2, and the second on floor E7 on top of layer E2.

Tell Masaïkh

New archeomagnetic intensity results

All the archeointensity measurements reported in this study were obtained using the experimental protocol developed by Le [START_REF] Goff | A new three-axis vibrating sample magnetometer for continuous high-temperature magnetization measurements: applications to paleoand archeo-intensity determinations[END_REF] for the Triaxe magnetometer. The details of this experimental protocol can be found in Le [START_REF] Goff | A new three-axis vibrating sample magnetometer for continuous high-temperature magnetization measurements: applications to paleoand archeo-intensity determinations[END_REF] (see also [START_REF] Genevey | Evidence for rapid geomagnetic field intensity variations in Western Europe over the past 800 years from new archeointensity French data[END_REF]2013;[START_REF] Hartmann | Archeointensity in Northeast Brazil over the past five centuries[END_REF]Gallet et al., 2014). We only recall here that it relies on magnetization measurements of a small specimen (<1cm 3 ) directly carried out at high temperatures and on a sequence of measurements (with successive heating and cooling cycles) automatically performed over a fixed temperature range between a low temperature referred to as T1 (typically of 150°C) and a high temperature referred to as T2 (typically between 500°C and 530°C).

In the past few years, a relatively large collection of archeointensity data of different ages and of different origins was obtained using the Triaxe, and comparative studies with results derived from more classical methods (i.e. from the [START_REF] Thellier | Sur l'intensité du champ magnétique tesrrestre dans le passé historique et géologique[END_REF] method as revised by [START_REF] Coe | Paleo-Intensities of the Earth's magnetic field determined from Tertiary and Quaternary Rocks[END_REF] or from the IZZI version of [START_REF] Thellier | Sur l'intensité du champ magnétique tesrrestre dans le passé historique et géologique[END_REF] method; e.g. [START_REF] Yu | Toward an optimal geomagnetic field intensity determination technique[END_REF]) demonstrated the reliability of the Triaxe intensity data when quality criteria are taken into account. In our study, we use the same quality criteria relative to the intensity determination for a specimen as those described by [START_REF] Genevey | Evidence for rapid geomagnetic field intensity variations in Western Europe over the past 800 years from new archeointensity French data[END_REF][START_REF] Hartmann | Archeointensity in Northeast Brazil over the past five centuries[END_REF][START_REF] Gómez | Caracterización del producto cerámico en las comunidades neolíticas de mediados del VI milenio cal BC: el valle del Éufrates y el valle del Khabur en el Halaf Final[END_REF], and which were also used more recently by [START_REF] Genevey | Geomagnetic field intensity variations in Western Europe over the past 1100 years[END_REF], Gallet et al. (2014) andGallet andButterlin (2014) (Supplementary Table 1). In particular, these criteria allow us to eliminate the data that could be biased due to alteration of the magnetic minerals during heating. Moreover, the temperature range over which the intensity determinations are recovered from each specimen is precisely adjusted so that the analyzed magnetization component is univectorial and corresponds to the magnetization acquired during the manufacture of the pottery. Fig. 3 shows two examples of demagnetization behaviors.

After the removal of the viscous low-temperature component, the first behavior shows a single magnetization component above ~200°C (SY89-08), while the second behavior reveals two components (SY140-06). In these cases, the temperature range was adjusted above ~200°C and ~340°C, respectively for obtaining intensity determinations at the specimen level. Finally, the intensity data should not be affected by the presence of multidomain magnetite grains and they take into account both the thermoremanent magnetization (TRM) anisotropy and cooling rate effects on TRM acquisition (for a thorough discussion on these aspects, see for instance in Le [START_REF] Goff | A new three-axis vibrating sample magnetometer for continuous high-temperature magnetization measurements: applications to paleoand archeo-intensity determinations[END_REF][START_REF] Genevey | ArcheoInt: An upgraded compilation of geomagnetic field intensity data for the past ten millennia and its application to the recovery of the past dipole moment[END_REF][START_REF] Genevey | Evidence for rapid geomagnetic field intensity variations in Western Europe over the past 800 years from new archeointensity French data[END_REF][START_REF] Hartmann | Archeointensity in Northeast Brazil over the past five centuries[END_REF].

Our archeointensity analyses were complemented by hysteresis measurements and by isothermal remanent magnetization (IRM) acquisition up to 0.8 T performed at Saint Maur using a laboratory-built inductometer coupled with an electro-magnet. In most cases, two fragments were analyzed for each group of fragments. IRM measurements show very similar behaviors with saturation reached in relatively low magnetic fields (~0.2-0.3 T), indicating the absence of high-coercivity minerals (Fig. 4a).

We note that the hysteresis loops are generally not constricted (Fig. 4b-c).

Thermomagnetic low-field susceptibility curves obtained using a KLY-3 Kappabridge coupled with a CS3 thermal unit show that the existing magnetic grains have maximum unblocking temperatures below 600°C (Fig. 4d-g). All these magnetic properties indicate that the magnetization of our specimens is most probably predominantly carried by minerals of the (titano)magnetite family. Furthermore, the thermomagnetic curves exhibit variable behaviors, independently of the age of the fragments, which suggests the presence of (titano)magnetite with different titanium contents or different grain sizes. We also observe a good reversibility between the heating and cooling susceptibility vs. temperature curves, which constitutes a good marker of the stability of the magnetic mineralogy on heating. We note that these magnetic properties are very similar to those we previously obtained from Syrian fired-clay artifacts of younger ages (e.g. [START_REF] Genevey | Eight thousand years of geomagnetic field intensity variations in the eastern Mediterranean[END_REF][START_REF] Gallet | Geomagnetic field intensity behavior in the Middle East between 3000 BC and 1500 BC[END_REF]2014;[START_REF] Gallet | Archaeological and geomagnetic implications of new archaeomagnetic intensity data from the Early Bronze high terrace "Massif Rouge" at Mari (Tell Hariri, Syria)[END_REF].

Except for one case, the hysteresis parameters obtained for the fragments from Tell Halula lie within the pseudo-single domain (PSD) range of magnetite defined by Dunlop et al. (2002a) when projected on a Day plot [START_REF] Day | Hysteresis properties of titanomagnetites: grain size and composition dependence[END_REF]. Most MRS/MS and HCR/HC ratios are concentrated inside a restricted area, with ~0.30>MRS/MS>~0.15 and ~4>HCR/HC>~2.5), above the theoretical mixing curves for mixture of SD and MD magnetite grains but also well below the mixing curve of SD and superparamagentic (SP) magnetite grains (Fig. 4h). According to Dunlop (2002b), this may reflect a large distribution of grain sizes, including SP, SD and MD magnetite grains. In contrast, most of the hysteresis parameters obtained from Tell Masaïkh (open blue triangles in Fig. 4h) fall within the theoretical SD-MD mixing curves defined by Dunlop (2002a), therefore indicating a coarser grain size distribution for those specimens. It is worth mentioning that the evolution of the techniques (preparation of the clay paste, firing conditions) used to produce ceramics at Tell Halula between the pre-Halaf and Halaf periods is clearly not reflected in the hysteresis ratios, their dispersions being very similar regardless of the age of the fragments (colored symbols in Fig. 4h). Further considering the data from Tell Masaïkh and the previous ones obtained from Ebla/Tell Mardikh (grey dots in Fig. 4h; Gallet et al., 2014), it appears that the distribution of the hysteresis parameters obtained at a given archeological site constitutes a magnetic signature of the clay source used to produce pottery at this site, and it may be used as an identification tool complementary to more classical chemical analyses. values. These intensity values are generally well defined, with a number of fragments analyzed per site larger or equal to 7 for 19 pottery groups (≥10 for 10 sites) and a standard deviation always of less than 5 µT, ranging between 1.8 % and 11.4 % of the corresponding group-mean intensity values (≤5.0 % for 10 sites and ≤7.5 % for 21 among the 24 studied pottery groups). We note, however, that the mean intensity value obtained for group SY125 (~6650-6550 BC) is only defined by two fragments (6 specimens), but it was kept for the discussion below because of the scarcity of such old archeointensity data.

Late Neolithic archeointensity variations in the Middle East

The new archeointensity data are reported in Fig. 6 (see also Supplementary Fig. 2, where the results are averaged over the successive occupation levels). The new results show that the time interval between ∼7000 BC and ~5000 BC was apparently marked in the Middle East by an overall decreasing trend in geomagnetic field intensity. This decrease was however not regular. In particular, a relative intensity minimum is observed at the beginning of the Late Halaf period (pottery group SY86-131 with 20 favorable fragments), around the middle of the 6th millennium BC. An intensity peak appears to have occurred during the Late Halaf period, between ∼5550 and ∼5300 BC. This intensity peak is supported by the low geomagnetic field intensity values obtained at Tell Masaïkh for the Halaf-Ubaid Transitional period.

We compared the new Tell Halula and Tell Masaïkh data with two other archeointensity datasets of the same age previously obtained in relatively nearby regions (Fig. 7). The first dataset includes results obtained at Yarim Tepe II and Tell Sotto, two multi-level archeological sites from northern Iraq (Fig. 1a; Nachasova andBurakov, 1995, 1998). In these two studies, the pottery fragments were selected and dated according to their stratigraphic position within a sequence of archeological deposits (with a total thickness of 780 cm at Yarim Tepe II and 280 cm at Tell Sotto), and assuming a constant accumulation rate of archeological deposits. Although such a sampling procedure may obviously introduce large uncertainties in the dating of the studied fragments, it nevertheless appears that this approach can provide satisfactory results (e.g. [START_REF] Nachasova | Geomagnetic variations in the VI-V millennia B[END_REF][START_REF] Kostadinova-Avramova | Contribution of stratigraphic constraints of Bulgarian prehistoric multilevel tells and a comparison with archaeomagnetic observations[END_REF].

However, in both cases, the dating considered by Nachasova andBurakov (1995, 1998) appears systematically shifted by several centuries relative to the most recent chronological Pottery Neolithic time scale (see [START_REF] Campbell | Rethinking Halaf chronology[END_REF][START_REF] Bernbeck | Established paradigms, current disputes and emerging themes: the state of research on the Late Neolithic in Upper Mesopotamia, in Interpreting the Late Neolithic of Upper Mesopotamia[END_REF]. Indeed, the fragments from Yarim Tepe II are unambiguously archeologically dated to the Middle-Late Halaf period (∼5750-5300 BC; e.g., [START_REF] Campbell | Rethinking Halaf chronology[END_REF][START_REF] Robert | Production céramique et représentations animales à l'époque de Halaf[END_REF][START_REF] Bernbeck | Established paradigms, current disputes and emerging themes: the state of research on the Late Neolithic in Upper Mesopotamia, in Interpreting the Late Neolithic of Upper Mesopotamia[END_REF] and references therein), but their ages were mostly assigned in the 5th millennium BC. Similarly, the fragments collected at Tell Sotto were dated to the middle of the 6th millennium BC by [START_REF] Nachasova | Geomagnetic variations in the VI-V millennia B[END_REF], but the studied ceramics are dated to the Late Pre-Halaf (Late proto-Hassuna and Archaic Hassuna cultural phases), i.e. between ∼6400 and ∼6050 BC (e.g. [START_REF] Bader | Earliest Cultivators in Northern Mesopotamia. The Investigations of Soviet Archaeological Expedition in Iraq at Settlements Tell Magzaliya, Tell Sotto[END_REF][START_REF] Bader | From pre-Pottery Neolithic to Pottery Neolithic in the Sinjar, in Interpreting the Late Neolithic of Upper Mesopotamia[END_REF]Le Mière pers. comm. 2014).

For these reasons, we assigned new ages to Yarim Tepe II and Tell Sotto considering first, the stratigraphic position of the concerned fragments as provided by the authors and second, assuming that the entire Middle-Late Halaf and Late Pre-Halaf periods were represented in the Yarim Tepe II and Tell Sotto deposits (like the authors considered but for two other time intervals). Finally, for displaying in Fig. 7a the data obtained at Yarim Tepe II, with only a single specimen studied per fragment, and at Tell Sotto we also performed intensity averaging over several fragments when the latter come from the same stratigraphic intervals, i.e. each time there was a group of fragments considered of the same age. We observe an overall good agreement with the data obtained at Tell Halula and Tell Masaïkh. In particular, this agreement confirms the occurrence in northern Mesopotamia of a relative intensity minimum around the middle of the 6th millennium BC, which further strengthens the occurrence of an intensity peak at the beginning of the second half of the 6th millennium BC.

The second archeointensity dataset comprises the results encompassing the 6th millennium BC from Bulgaria that were recently updated by [START_REF] Kovacheva | Extended and revised archaeomagnetic database and secular variation curves from Bulgaria for the last eight millennia[END_REF] (Fig. 7b). From this new analysis, a century-scale intensity peak seems to be emerging around the middle of the 6 th millennium, which might coincide, within age uncertainties, with that observed from the Syrian Late Halaf data. According to this interpretation, the data available for the Halaf-Ubaid Transitional period would come prior to the geomagnetic field intensity increase observed in the Bulgarian data at the end of the 6 th millennium BC. Constraining further this preliminary correlation will require the acquisition of new archeointensity data in the Balkans and in the Middle East.

Discussion

We have undertaken the construction of a geomagnetic field intensity secular variation curve in the Middle East during the Holocene. For this purpose, we selected all the archeointensity data available inside a circle with a radius 1000 km around the archeological site of Tell Halaf (λ=36°49'N, φ=40°02'E; Supplementary Fig. 3). The data were retrieved from the ArcheoInt database [START_REF] Genevey | ArcheoInt: An upgraded compilation of geomagnetic field intensity data for the past ten millennia and its application to the recovery of the past dipole moment[END_REF] and complemented with the more recent studies [START_REF] Ben-Yosef | Geomagnetic intensity spike recorded in high resolution slag deposit in southern Jordan[END_REF][START_REF] Gallet | Archéomagnétisme à Mishirfeh-Qatna: Nouvelles données sur l'évolution de l'intensité du champ magnétique terrestre au Moyen-Orient durant les derniers millénaires[END_REF][START_REF] Shaar | Geomagnetic field intensity: How high can it get? How fast can it change? Constraints from Iron-Age copper-slag[END_REF][START_REF] Shaar | Decadal-scale variations in geomagnetic field intensity from ancient Cypriot slag mounds[END_REF][START_REF] Ertepinar | Archaeomagnetic study of five mounds from Upper Mesopotamia between 2500 and 700 BC: further evidence for an extremely strong geomagnetic field ca. 3000 years ago[END_REF]Gallet et al., 2014;[START_REF] Gallet | Archaeological and geomagnetic implications of new archaeomagnetic intensity data from the Early Bronze high terrace "Massif Rouge" at Mari (Tell Hariri, Syria)[END_REF].

They were obtained from the eastern part of Turkey, Cyprus, Syria, the Levant, Iraq, from the western part of Iran and from the Caucasus. Note that the large dataset from the Balkans and Greece (e.g. De [START_REF] De Marco | New archeointensity resulst from archeological sites and variations of the geomagnetic field intensity for the last 7 millennia in Greece[END_REF][START_REF] Tema | Secular variation of the Earth's magnetic field in the Balkan region during the last eight millennia based on archaeomagnetic data[END_REF][START_REF] Kovacheva | Extended and revised archaeomagnetic database and secular variation curves from Bulgaria for the last eight millennia[END_REF] has not been included to allow it to be compared to different regional secular variation behaviors from elsewhere (e.g. between the Middle East, Eastern Europe and Western Europe). [START_REF] Genevey | ArcheoInt: An upgraded compilation of geomagnetic field intensity data for the past ten millennia and its application to the recovery of the past dipole moment[END_REF] proposed a set of selection criteria in order to distinguish between all available data those that meet minimum quality criteria. This approach enabled the construction of two datasets referred to as "Selected data" and "All data" in [START_REF] Genevey | ArcheoInt: An upgraded compilation of geomagnetic field intensity data for the past ten millennia and its application to the recovery of the past dipole moment[END_REF]. Hereafter we have considered the compilation of selected data to calculate the Middle East geomagnetic field intensity variation curve, considering the new dating we estimated for Tell Sotto and Yarim Tepe II and using, for these two sites, the mean intensity values computed from fragments associated with the same stratigraphic level (Fig. 7a).

To calculate our curve, we first applied a method based on the use of sliding windows of 200 years successively shifted by 10 years through the past 9 millennia. We computed VADM values only for those time intervals containing at least 3 results.

Following Thébaut and Gallet (2010) and [START_REF] Licht | Ensembles of low degree archeomagnetic field models for the past three millennia[END_REF], we also used the bootstrap technique with 1000 runs by introducing random noise in the data within their experimental and age uncertainties. This allowed us to compute 1000 intensity variation curves. In Fig. 8a we displayed the averaged VADM (thick line) together with the minimum and maximum VADM values obtained for the different sliding windows, hence defining an envelope of equally possible VADM values. Due to the insufficient number of archeointensity data spanning the 5th and 4th millennia BC, no averaged curve could be determined between ∼4930 BC and ∼3650 BC, i.e. during the Ubaid and Uruk periods in Mesopotamia. This time interval therefore constitutes a particularly important target for future archeomagnetic studies in the Middle East. For other periods, the computed curve appears very consistent with almost all the Syrian data (blue dots in Fig. 8a; [START_REF] Genevey | Eight thousand years of geomagnetic field intensity variations in the eastern Mediterranean[END_REF]Gallet and Le Goff, 2006;Gallet et al., 2006[START_REF] Gallet | Geomagnetic field intensity behavior in the Middle East between 3000 BC and 1500 BC[END_REF]Gallet et al., , 2014;;[START_REF] Gallet | Archéomagnétisme à Mishirfeh-Qatna: Nouvelles données sur l'évolution de l'intensité du champ magnétique terrestre au Moyen-Orient durant les derniers millénaires[END_REF]Gallet and Butterlin, 2014 and this study). We observe the same variation trends, with distinct intensity maxima during the second half of the first millennium AD, at the beginning of the first millennium BC and around the middle of the third millennium BC. Supplementary Fig. 4 also exhibits the averaged intensity curve computed without the Syrian data, showing in particular that the latter data set allows us to better constrain the curve during the third millennium BC (note that this curve takes into account the new dating of the Tell Sotto and Yarim Tepe II data). The temporal resolution of 200 years of the regional averaged curve most probably prevents the recovery of distinct century-scale intensity (VADM) maxima at ∼1500 BC, ∼2550 BC and ∼2300 BC clearly observed from Syrian data at Ebla and Mari [START_REF] Gallet | Geomagnetic field intensity behavior in the Middle East between 3000 BC and 1500 BC[END_REF](Gallet et al., , 2014;;[START_REF] Gallet | Archaeological and geomagnetic implications of new archaeomagnetic intensity data from the Early Bronze high terrace "Massif Rouge" at Mari (Tell Hariri, Syria)[END_REF], as well as the maximum in intensity between ∼5500 and ∼5300 BC exhibited by the Tell Halula data or the spike events proposed by [START_REF] Ben-Yosef | Geomagnetic intensity spike recorded in high resolution slag deposit in southern Jordan[END_REF] and [START_REF] Shaar | Geomagnetic field intensity: How high can it get? How fast can it change? Constraints from Iron-Age copper-slag[END_REF] at the very beginning of the first millennium BC.

The second approach is similar to the method described above but relies on the more complex cubic B-splines time parameterization and uses an iterative scheme to identify and then to weight the data that are considered as outliers (Fig. 8b; modified from [START_REF] Thébault | A bootstrap algorithm for deriving the archeomagnetic field intensity variation curve in the Middle East over the past 4 millennia BC[END_REF]. The algorithm first proposes a set of possible spline knots irregularly spaced. The spacing is designed to take full advantage of the varying time resolution between epochs that arises from the uneven time distribution of the reference archeomagnetic data. For instance, it is found that the maximum achievable time resolution is about 150 years between 7000 BC to about 5000 BC and between ∼3000 BC and 2000 AD, while searching for features with time resolution lower than 800 years makes little sense between ∼5000 BC and ∼3000 BC. Then, the data are as before 1000 times randomly noised within their a priori error bars. For each curve, the algorithm checks whether the maximum likelihood solution belongs to the a priori 95% error bar of the data and weights accordingly the data that are systematically outside this confidence interval. Fig. 8b displays the final solution with the maximum probability in black and its 95% fluctuation envelope in light blue. This envelope contains 95% of the maximum likelihood curves estimated by the bootstrap for the 1000 iterations, and it highlights the variability between the different curves. This parameter is important for testing the precision of the most probable curve and for identifying the fine time variations that persist after resampling. Formally, however, the statistical significance of a time variation can be assessed only after the computation of the 95% confidence interval (in red) that is traditionally calculated a posteriori from the misfit function between the data and the ensemble of models. Compared to the first approach, the likelihood solution provided in supplementary Table 3 is generally smoother. This feature is desired for testing whether the apparent fine time variation of the maximum likelihood can be considered as robust. A striking feature emerging from the comparison between Fig. 8a and Fig. 8b is that the final solution is independent of the chosen modeling scheme. This is seemingly positive evidence that the observed magnetic field intensity variations are well constrained (within the given time resolution) by the available data in the chosen geographical area.

We then sought to constrain the variations in global geomagnetic dipole field moment over the past 9 millennia. For this, we averaged the archeointensity data available in the Middle East over sliding windows of 500 years, roughly assuming that this rather long duration may suffice to average out most of the non-dipole contributions (e.g. [START_REF] Hulot | A statistical approach to the Earth' s main magnetic field[END_REF][START_REF] Genevey | ArcheoInt: An upgraded compilation of geomagnetic field intensity data for the past ten millennia and its application to the recovery of the past dipole moment[END_REF][START_REF] Knudsen | Variations in geomagnetic dipole moment during the Holocene and the past 50 kyr[END_REF].

On the other hand, this averaging smoothes out the more rapid variations in dipole moment over centennial time scales [START_REF] Genevey | Evidence for rapid geomagnetic field intensity variations in Western Europe over the past 800 years from new archeointensity French data[END_REF]2013). The curve constructed using the same technique as in Fig. 8a is shown in Fig. 9a, together with the VADM computed by [START_REF] Knudsen | Variations in geomagnetic dipole moment during the Holocene and the past 50 kyr[END_REF] using the global GEOMAGIA50 database [START_REF] Korhonen | GEOMAGIA50: An archeointensity database with PHP and MySQL[END_REF] and applying both temporal and geographical averaging to eliminate the non-dipole components. As a general comment, the two curves exhibit the same dipole behavior during the past three millennia (although the magnitude and the amplitude of the variations are not strictly the same), characterized by two periods of stronger dipole moment during the first millennium BC and during the second half of the first millennium AD (see also [START_REF] Genevey | ArcheoInt: An upgraded compilation of geomagnetic field intensity data for the past ten millennia and its application to the recovery of the past dipole moment[END_REF][START_REF] Hong | Globally strong geomagnetic field intensity circa 3000 years ago[END_REF]. In contrast, these curves are significantly different during the third millennium BC, with a smooth VADM evolution in the case of the [START_REF] Knudsen | Variations in geomagnetic dipole moment during the Holocene and the past 50 kyr[END_REF] curve but with a distinct dipole maximum in our Middle East curve. For older periods, there is again a good consistency between the two curves, but we note the large error bars of Knudsen et al.'s (2008) curve for the 7th-6th millennium segment. Thus the question remains as to the significance of the dipole maximum observed in the Middle East during the third millennium BC, which is well constrained by a significant number of data. Owing to the rather good agreement between the two curves, especially during the past three millennia, the VADM maximum we observe during the third millennium BC might well be a global (dipole) geomagnetic feature that requires further confirmation. If true, it would indicate that the dipole evolution varied more erratically than previously thought, with an oscillatory behavior at least between ~3000 BC and 2000 AD of typical time scale of about 1700 years (see also [START_REF] Burakov | Wavelet analysis of geomagnetic field intensity for the past 4000 years[END_REF].

Fig. 9b compares our VADM variation curve with dipole moments derived from global geomagnetic field modeling that was recently constructed using only archeomagnetic and volcanic data (Pavón-Carrasco et al., 2014, in blue) and another that also incorporated paleomagnetic data from sediments [START_REF] Nilsson | Reconstructing Holocene geomagnetic field variation: New methods, models and implications[END_REF] in orange and green; note that this latter reconstruction supersedes the previous field reconstruction of [START_REF] Korte | Reconstructing the Holocene geomagnetic field[END_REF]. The field models that partly rely on sediment data naturally show time variations smoother than that of the models constructed using only the archeomagnetic and volcanic data. Hence, the dipole moments derived by [START_REF] Nilsson | Reconstructing Holocene geomagnetic field variation: New methods, models and implications[END_REF] during the 7th millennium BC are lower than the ones proposed by [START_REF] Pavón-Carrasco | A geomagnetic field model for the Holocene based on archaeomagnetic and lava flow data[END_REF] and lower than the averaged VADM we estimated from the Middle East. However, at the beginning of the first millennium BC, the VADM values from the Middle East are much higher than the dipole moments from either models. Neither of two reconstructions shows the distinct dipole maxima previously observed during the past three millennia (Fig. 9a; [START_REF] Genevey | ArcheoInt: An upgraded compilation of geomagnetic field intensity data for the past ten millennia and its application to the recovery of the past dipole moment[END_REF][START_REF] Knudsen | Variations in geomagnetic dipole moment during the Holocene and the past 50 kyr[END_REF], in particular the one dated to the first millennium AD. This clearly poses the question of the consistency between the VADM estimates and the time-varying dipole moment reconstructions.

Nevertheless, it could be argued that the field modeling of [START_REF] Pavón-Carrasco | A geomagnetic field model for the Holocene based on archaeomagnetic and lava flow data[END_REF] gives some support to the occurrence of a dipole moment maximum during the third millennium BC (Fig. 9b). Such an agreement still needs to be confirmed because the proposed field reconstruction shows numerous centennial-scale fluctuations with similar amplitudes over the entire sequence, a feature whose geomagnetic origin is questionable.

As a concluding remark, we point out that the different time-varying archeomagnetic field reconstructions encompassing the 7th-5th millennium time interval all suffer from the erroneous dating affecting the Yarim Tepe II and Tell Sotto data. Together with the corrected Yarim Tepe II and Tell Sotto ages, the new archeointensity data obtained in the present study dated to between 7000 BC and 5000 BC will help improve the reliability of the next generation of geomagnetic field models spanning the Late Neolithic period. Besides implications for geomagnetism, this improvement may be of particular interest in providing chronological time constraints for archeological purposes, during a fascinating period (e.g. [START_REF] Berger | The 8200 calBP abrupt environmental change and the Neolithic transition: A Mediterranean perspective[END_REF] that was marked by the beginning of the Neolithic expansion from the Middle East toward Western Europe. Tell Halula; f, Tell Masaïkh). Each colored curve on each of these plots shows the intensity data obtained for one specimen over the temperature range of analysis (for further explanations, see in Le [START_REF] Goff | A new three-axis vibrating sample magnetometer for continuous high-temperature magnetization measurements: applications to paleoand archeo-intensity determinations[END_REF]. Altogether, the results from 93 specimens are hence reported in this Figure. 1). Fig. 7. Comparison between our new archeointensity data (in blue) and previous results obtained (a) from Yarim Tepe II and Tell Sotto (green circles and triangles, respectively), two multi-level archeological sites located in North Iraq (Nachasova andBurakov, 1995, 1998) and (b) from Bulgaria (in red; [START_REF] Kovacheva | Extended and revised archaeomagnetic database and secular variation curves from Bulgaria for the last eight millennia[END_REF]. As discussed in the text, the dating of the Yarim Tepe II and Tell Sotto data was modified from the original papers. all other available archeointensity data (grey dots) satisfying minimum selection criteria [START_REF] Genevey | ArcheoInt: An upgraded compilation of geomagnetic field intensity data for the past ten millennia and its application to the recovery of the past dipole moment[END_REF]. (b) We used an iteratively reweighted least-squares algorithm, combined with a bootstrap, modified from that of [START_REF] Thébault | A bootstrap algorithm for deriving the archeomagnetic field intensity variation curve in the Middle East over the past 4 millennia BC[END_REF]. The continuous black line shows the maximum of probability, and the light blue lines its 95% fluctuation envelope. The 95% confidence interval is displayed by the red lines. We recover the regional geomagnetic intensity variations between ~7000 BC and ~5000 BC A 9000-years long archeointensity variation curve is constructed for the Middle East

Figure captions

We constrain the variations in the dipole field moment over most of the Holocene

  The systematic archeological fieldwork at Tell Halula has brought significant knowledge about the development of farming, especially in the final stages of the Neolithisation process, when economic, technological and cultural changes were being consolidated. The different phases of human occupation have been recovered in several sectors, especially in the south, south-east and central parts of the settlement (Sectors 1,

  age assignment was established via stratigraphy, with the group of potsherds SY96 being the most recent, SY97-129 intermediate and SY98-128 being the oldest. Finally, pottery group SY130, comprising pottery fragments found in a pit from Sector 49, comes from the late pre-Halaf (Ceramic Phase III; ~6300-6050 BC).

  For the period referred to as proto-Halaf (~6050-5900 BC), corresponding to Ceramic Phase IV defined at Tell Halula, two pottery groups of household artifacts were collected in Sectors 44 (SY94-137) and 40 (SY95). A single group (SY91) lies within the Early Halaf period (Ceramic Phase V; ~5900-5750 BC), which was recovered from a multicellular house located in sector 44. Different pits discovered in the same area of Sector 45 yielded four contemporaneous groups of pottery (SY87, SY88, SY89, SY90) dated within the Middle Halaf period (Ceramic Phase VI; ~5750-5550 BC).

  The archeological site of Tell Masaïkh (λ=34°25'N, φ=40°01'E) is located on a river terrace in the middle Euphrates Valley (left bank), in the modern province of Deir ez-Zor (eastern Syria). Discovered in 1996 by the Mission Archéologique Française de Ashara/Terqa led by O. Rouault, excavations at Tell Masaïkh (~4 km from Terqa), conducted under the leadership of M.-G. Masetti-Rouault, have revealed several phases of occupation starting with the Late Neolithic (Halaf). More recent periods include significant Neo-Assyrian remains, with a citadel and a palace dated in the 9 th -8 th centuries BC (Iron Age period), which led the identification of Tell Masaïkh as the Assyrian city named Kar-Assurnasirpal (see general discussion in Masetti-Rouault, 2010). The discovery in the western sector D of Tell Masaïkh of an artisanal Halaf settlement makes this site also quite unique. It is located away from most other known Halaf archeological sites situated more to the North with rainfall above 250 mm/year (while rainfall is below this isohyet in the Tell Masaïkh region; e.g. Masetti-Rouault, 2006; Robert, 2010), which opens discussion on farming systems and on the use of irrigation at this time. Excavations of the Halaf levels at Tell Masaïkh unearthed several occupation levels in open areas with fire places (tannurs), several kilns probably for pottery production and a 1.5 m-thick, ~20 m-long stone wall that supported a terrace. A rich ensemble of Late Halaf potsherds was also recovered. The potsherds analyzed in the present study were found in the uppermost layers dated in the Halaf-Ubaid Transitional (~5300-5000 BC; e.g. Campbell and Fletcher, 2010) based on their typology and from the painted decoration that used manganese pigments for black color. The youngest Halaf pottery belongs to polychrome Late Halaf types associated with some Impressed

Fig. 5

 5 Fig. 5 shows the intensity results obtained from eight pottery groups. Each curve from each panel shown in this figure exhibits the intensity data obtained for one specimen over a temperature range often exceeding 200-250°C. In general, we only analyzed one specimen per fragment. However, when the number of favorable fragments was ≤ 5 (i.e. for pottery groups SY127, SY125, SY95, SY38), we analyzed three specimens from each fragment and we first estimated a mean intensity value at the fragment level before computing a mean value at the group level. The success rate of our archeointensity analyses significantly varies according to the archeological periods. While it is only 36% for the pre-Halaf period (54 fragments from 151 analyzed fragments) and 56 % (22 from 39 fragments) for the proto-Halaf period, it increases up to 70% for the sites dated in the Halaf period (133 from 191 fragments) and 67% for the Halaf-Ubaid Transitional period (16 favorable fragments from 24 studied fragments). The relatively low success rate for the pre-Halaf fragments is mainly due to the presence of two magnetization components, which is likely related to the use of these ceramics for cooking (hence preventing in many cases the clear isolation of a primary magnetization). Examples of failed results are reported in Supplementary Fig. 1. Overall, we analyzed a total of 405 fragments, among which 225 fragments (254 specimens) yielded favorable archeointensity results, allowing us to determine 24 mean intensity values at the pottery group level. Results obtained at the specimen/fragment level are detailed in SupplementaryTable 2, while Table 1 provides the group-mean intensity

  φ=38°10'E; pottery groups SY127 to SY132) and Tell Masaïkh (λ=34°25'N, φ=40°01'E; pottery groups SY37 and SY38). Information on the different archeological dating, relative chronology and references are provided in the second, third and fourth columns. See text for references on absolute dating (fifth column). * indicates that an approximation was made on the dating (see text). The mean intensity values and their standard deviations are provided in column 6. Column 7 shows the number Nb of fragments (/n specimens) retained for computing the pottery group-mean intensity values.

Fig. 1 .

 1 Fig. 1. (a) Location of the two Syrian archeological sites studied herein (Tell Halula and Tell Masaïkh) and of three other sites discussed in the text (Tell Halaf, Yarim Tepe II and Tell Sotto). ©Google Earth. (b) General view of the Tell Halula archeological site. © Universitat Autónoma de Barcelona (UAB)/SAPPO.

Fig. 2 .

 2 Fig. 2. Examples of pottery sherds discovered at Tell Halula. These fragments are dated to phases I, II and III of the pre-Halaf (photos 1-2, 3-4 and 5-6, respectively), to the proto-Halaf (photos 7-8), and to the Early, Middle and Late Halaf (photos 9, 10-11 and 12-13, respectively). © Universitat Autónoma de Barcelona (UAB)/SAPPO.

Fig. 3 .

 3 Fig. 3. Triaxe intensity data obtained for two specimens from Tell Halula (SY89-08, SY140-06). (a,c) Thermal demagnetization data; (b,d) Triaxe measurement series; (e)Archeointensity results at the specimen level. See text and further explanations in Le[START_REF] Goff | A new three-axis vibrating sample magnetometer for continuous high-temperature magnetization measurements: applications to paleoand archeo-intensity determinations[END_REF].

Fig. 4 .

 4 Fig. 4. (a) Normalized IRM acquisition curves obtained for one fragment from each time level. (b-c) Two examples of hysteresis loop. (d-g) Four examples of normalized thermomagnetic low-field susceptibility (heating and cooling) curves obtained from fragments collected at Tell Halula. These fragments are dated to the pre-Halaf (d,e), Middle Halaf (f) and to the Late Halaf (g). (h) Hysteresis ratios (MRS/Ms vs. HCR/HC) obtained at Tell Mardikh/Ebla (grey color, Gallet et al., 2014), Tell Masaïkh (blue

Fig. 5 .

 5 Fig. 5. Intensity data obtained from eight different archeomagnetic pottery groups (a-e,

Fig. 6 .

 6 Fig. 6. Archeomagnetic field intensity variations recovered from the new data obtained at Tell Halula (blue circles) and Tell Masaïkh (blue triangles). All results are converted in Virtual Axial Dipole Moments. The chronological time scale is provided in the text (see also in Table1).

  The solid vs. open circles indicate the intensity values obtained from several vs. one specimen(s).

Fig. 8 .

 8 Fig. 8. Regional averaged geomagnetic field intensity variation curve in the Middle East over the past 9000 years. The data were selected inside a 1000 km-radius circle around the location λ=36°49'N, φ=40°02'E (archeological site of Tell Halaf). All data were transformed into VADM. Two different approaches were successively considered to compute the curve. (a) We used sliding windows of 200 years shifted every 10 years and the bootstrap technique for taking into account the experimental and age uncertainties on the available intensity data. 1000 curves were hence computed and are shown here the mean (thick black line), the minimum and the maximum VADM values obtained for the different time windows. The Syrian data are also reported (blue dots) together with

Fig. 9 .

 9 Fig. 9. Comparison between the geomagnetic field intensity (transformed into VADM) variation curve in the Middle East, with averaging over sliding windows of 500 years (black lines; see text), and previous dipole field moment reconstructions. The comparison is made with (a) the VADM variation curve computed by Knudsen et al. (2008) using temporal and geographic averaging (in red), (b) dipole moment reconstructions derived from different time-varying global geomagnetic field modeling (blue lines, modeling proposed by Pavón-Carrasco et al., 2014; orange and green lines, the pfm9k.1b and pfm9k.1a modeling proposed by Nilsson et al., 2014).

  Figure 6

  Figure 9

Table 2 ,

 2 while Table 1 provides the group-mean intensity

Table caption Table 1 .

 caption1 Pottery group-mean intensity values obtained at Tell Halula (λ=36°25'N,

Acknowledgements

We thank Michel Al Maqdissi (DGAM, Damascus), who made possible this archeomagnetic study. We are also grateful to Stuart Gilder and 2 anonymous reviewers for helpful comments on the manuscript. Y.G. and I.N. were partly financed by grant of the Russian Ministry of Science and Education N 14.Z50.31.0017. IPGP contribution no.

Xxx


François Fouquet

Grégory Nain

Erwan Daubert

Johann Bourcier

Olivier Barais

Noel Plouzeau

Brice Morin

Designing and Evolving Distributed Architecture using Kevoree

Modern software applications are distributed and often operate in dynamic contexts, where requirements, assumptions about the environment, and usage profiles continuously change. These changes are difficult to predict and to anticipate at design time. The running software system should thus be able to react on its own, by dynamically adapting its behavior, in order to sustain a required quality of service. A key challenge is to provide the system with the necessary flexibility to perform self-adaptation, without compromising dependability. Models@Runtime is an emerging paradigm aiming at transferring traditional modeling activities (focusing on quality, verification, and so on) performed by humans, to the running system. In this trend, Kevoree provides a models@ runtime platform to design heterogeneous, distributed and adaptive applications based on the component based software engineering paradigm. At the end of this tutorial, applicants will be able to develop and assemble new components and communication channel to design complex self-adaptable distributed architectures by reusing existing piece of code.

PRESENTERS

Dr François Fouquet is Research Associate at SnT Luxembourg. He holds a Master degree in Software Engineering at the University of Rennes 1 in 2009 and he obtained his PhD thesis from the Triskell research group in Rennes in 2013. His main activities are related to Model-Driven Engineering, Dynamically Adaptable Cyber Physical Systems and Search-based and evolutionary algorithms. As main contributor of the Kevoree project, he namely contributes to apply it to drive Cyber Physical Systems and massive distributed systems such as Cloud computing. Today he is involved in the SmartGrid project for the Luxembourg City, trying to make Smart Cities more sustainable using sensors values.

Dr Olivier Barais (http://goo.gl/fQOF7) is an Associate Professor at the University of Rennes 1, member of the Triskell INRIA research team. He received an engineering degree from the Ecole des Mines Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage, and that copies bear this notice and the full citation on the first page. Copyrights for third-party components of this work must be honored. For all other uses, contact the owner/author(s). As head of the Internet of Things Laboratory Infrastructure of the SnT, his main activities focus on supporting research activities related to the Internet of Things domain and Cyber Physical Systems, by providing help for the realization of tests, experimentations and validations of IoT-related software systems. He is also participating to the Kevoree project effort, and uses this development platform and Model-Driven Engineering approaches to implement the IoT Lab base software system.

DURATION

The workshop duration is half a day (4 hours). The type of tutorial will be a hands-on tutorial. This tutorial requires a room with wireless access for participants. We expect 15-20 participants.

SCOPE

The intended audience is both software engineers/researchers and PhD students. The attendants must have a laptop with Virtual Box installed or a laptop with a JDK 1.8 and a recent Java IDE. The attendants must be familiar with Java or any Object Oriented Technology. Academics and practitioners alike will benefit from the tutorial. We expect that the presentation is of particular interest for builders of distributed tools and algorithms, both academics and practitioners, who would like to have abstractions to deal with heterogeneous and distributed adaptive applications.

GOAL AND OBJECTIVES

The goal of this tutorial is to provide the fundamentals of the Kevoree framework language for designing heterogeneous and distributed adaptive applications.

The goal of this tutorial is to present Kevoree through a practical session to a wide number of Software Engineering practitioners. This event would be a great venue for people to learn-by-example about dynamic adaptations, distribution and continuous design in a reliable environment. This tutorial is also intended to be a privi-leged moment to collect comments and feedback on our approach and realizations.

This overall goal can be broken down into several concrete subobjectives:

1. Component development Use the Kevoree Annotation API to create component types, then use a Kevoree Maven plugin to extract the components' models at compile time.

2. Assembly (graphical & script) Use editor to assemble an application through a graphical DSL or through the use of a Kevoree Script.

3. Deployment on (single & multiple) node Experiment the simple deployment on single vs multiple execution nodes.

Continuous Design

Experiment the continuous design facilities of Kevoree that shorten the development cycles.

5. Development of Self-Adaptive system Design and create a self-adaptive system, through the development of a simple ECA reactive system.

6. Cloud infrastracture management Deployment of an application in a private Cloud, and perform cross-layer adaptations using the Kevoree abstraction.

OVERVIEW OF THE TUTORIAL

The tutorial divides into four main parts here described.

Part 0 -Introduction (20 min talk -20 min Prerequisites)

Presentation This first part introduces models@runtime and the Kevoree Framework. After a bit of history, some facts, and examples of realizations, the participants prepare their machines with the necessary tools for the following parts.

Prerequisites The practical session of this part ensures that a JDK and a JavaIDE are available.

Material http://kevoree.org/doc/

Part 1 -The basics (20 min talk -30 min hands-on)

Presentation In this part, the different basic features manipulated in Kevoree are presented. Participants get familiar with the Domain Specific language used in Kevoree to deal with distributed systems.

Practical The participants discover the Kevoree Editor and During and Runtime in this practice. They have to create a first application, deploy it and run it. Practical In this session, attendees complete and change a sample Producer/Consumer component code. They then go through the entire chain from development to deployment and experience the continuous design abilities of Kevoree. Through this session, they will also discover the Kevoree development plugins within Eclipse or IntelliJ.

Material http://kevoree.org/practices/level1/ 5.4 Part 3 -Self-Adaptation@Runtime (15 min talk -45min hands-on)

Presentation Finally, we present the principle of using Models@Runtime to develop self-adaptive systems, that can autonomously adapt at runtime.

Practical Participants have to two kinds of reasonning engine. (i) a simple Event-Condition-Action reasoner that modifies the model of the running system and ask for an adaptation at runtime. (ii) an advanced reasonning engine that uses genetic algorithms to explore the architectural solution space to find a suitable architecture on a multi-criteria decision challenge.

Material http://kevoree.org/practices/level2/ 5.5 Part 4 -Cloud adaptation using Kevoree (10 min talk -30 min hands-on))

Presentation This part presents how the abstractions provided by Kevoree can be used to drive a cross-layer cloud adaptation).

Practical Participants have to design a simple architecture to drive several system virtual machines (built on top of LXC (https://github.com/lxc/lxc)).

Material http://kevoree.org/practices/level3/

RESOURCES

Resources about Kevoree are available at http://www.kevoree. org. The source code is available on Github. Some talks given about Kevoree are proposed online along with video tutorials. This tutorial was delivered during the Middleware conference in 2013. (http://2013.middleware-conference.org/tutorial.html)

  Material http://kevoree.org/practices/level0/ 5.3 Part 2 -Do-It-Yourself (20 min talk -30 min hands-on) Presentation The presentation of this session describes how to create a Kevoree Component Type. It introduces the Annotation API, used to describe the component type in the code, and the Compilation Chain to extract the component model at compile time, and create the component library.

Acknowledgments

This project is partially funded by the European Commission under the Seventh (FP7 -2007-2013) Framework Programme for Research and Technological Development in the context of the Heads project. The research activities were also conducted in the context of ITEA2-MERgE (Multi-Concerns Interactions System Engineering, ITEA2 11011), a European collaborative project with a focus on safety and security.