Mr. Ludovic Mr Jérôme Fortin

Ms Bodet

Laetitia

Keywords: Plateforme carbonatée, Propriétés acoustiques, Interprétation sismique, Analyse de vitesse, Modélisation sismique synthétique, Géophysique de réservoir, Bassin du Levant, Propriétés du réservoir, Sédimentologie, Faciès, Diagenèse Carbonate platform, Acoustic properties, Seismic interpretation, Velocity analysis, Synthetic seismic modelling, Reservoir geophysics, Levant basin, Reservoir properties, Sedimentology, Facies, Diagenesis. IX

the seismic data essential for this work, and providing access to Petrel software at their office in Beirut. The GEOPS laboratory at Paris Saclay university is also thanked for providing their facilities and equipment to conduct the petrophysical measurements on rock samples.

My warmest thanks go to my family who have given me the

List of Tables

 Table 1.Facies description of the 2D section from Valanges fm compared to Lithofacies described in [START_REF] Thomas | Contribution of drone photogrammetry to 3D outcrop modeling of facies, porosity, and permeability heterogeneities in carbonate reservoirs (Paris Basin, Middle Jurassic)[END_REF] [START_REF] Dunham | The chronostratigraphic significance of seismic reflections along the Bahamas Transect[END_REF] depositional classification of carbonates (modified after [START_REF] Dunham | The chronostratigraphic significance of seismic reflections along the Bahamas Transect[END_REF][START_REF] Embry | A Late Devonian reeftract on Northeastern Banks Island, NWT[END_REF][START_REF] Loucks | Introduction to Carbonate Environments, Facies, and Facies Tracts[END_REF] crossing along the 2D onshore seismic profile pathway (scale 1:50,000 -constructed after Dubertret, 1955Dubertret, , 1975;;Hawie et al, 2014;Nader et al. 2016) The Levant Basin is located in the easternmost part of the Mediterranean region (Fig. 1). It represents an attractive area in terms of hydrocarbon play. In particular, offshore Lebanon is extensively mapped with seismic survey but lacks well log data. In reservoir characterization, well log data provides insights into rocks' petrophysical properties, lithology, and connectivity.

In the absence of well calibration, outcrops can play a key role as analogue for the subsurface platforms, which helps to make the critical link between seismic data and the subsurface strata (Kleipool et al. 2017).

While the Levant Basin is primarily known for its natural gas discoveries (Fig. 1) in Cretaceous sandstone reservoirs (e.g., Tamar, Leviathan, and Aphrodite fields in the southeastern part of the Levant Basin), recent studies focused on the northern part of the Levant Basin suggest possible petroleum potential in the carbonate platforms of Jurassic -Cretaceous and Upper Cretaceous -Oligo -Miocene platforms, such as the Zohr gas field discovered offshore Cyprus in 2011, consisting of Miocene-aged carbonates (Nader et al. 2004;Nader et al. 2006;Hawie et al., 2015;[START_REF] Bou Daher | 3D thermal history and maturity modelling of the Levant Basin and its eastern margin, offshoreonshore Lebanon[END_REF][START_REF] Nader | Key geological characteristics of the Saida-Tyr Platform along the eastern margin of the Levant Basin, offshore Lebanon: implications for hydrocarbon exploration[END_REF][START_REF] Ghalayini | Petroleum Systems of Lebanon: recent advances and future potential[END_REF].

Carbonate rocks are characterized by vast heterogeneities resulting from different depositional fabrics and their susceptibility to diagenetic processes [START_REF] Lucia | Carbonate Reservoir Characterization[END_REF][START_REF] Harris | Delineating and quantifying depositional facies patterns in carbonate reservoirs: insight from modern analogs[END_REF]Hendry et al. 2021). This results in spatial changes in the petrophysical properties of rocks, thus, creating secondary microstructures enhanced by diagenetic modifications (Wagner 1997;Fournier and Borgomano 2007;Soute et al. 2015;Bailly et al. 2019a). Indeed, carbonates show a wide range of velocity and acoustic impedance values which can cause the disruption of seismic images and complicate their interpretation [START_REF] Anselmetti | Sonic velocity in carbonates -A combined product of depositional lithology and diagenetic alterations[END_REF]Fournier and Borgomano 2007).

The interpretation of seismic data follows the principles of seismic stratigraphy based on the mapping of seismic reflectors as geological timelines (Vail et al. 1977;Mitchum 1977;Eberli et al. 2002). Seismic reflections result from differences in acoustic impedance values, the product of sonic velocity and density (Sheriff 1977).

In this context, seismic facies analysis is a useful tool to improve the interpretation of seismic data in carbonate platforms (Berg 1982;Fontaine et al. 1987). Indeed, it is fundamental to comprehend the geological and depositional background, as well as the rock properties of a carbonate system to make a robust seismic facies interpretation [START_REF] Burchette | Carbonate rocks and petroleum reservoirs: a geological perspective from the industry[END_REF][START_REF] Lanteaume | Testing geologic assumptions and scenarios in carbonate exploration: Insights from integrated stratigraphic, diagenetic, and seismic forward modelling[END_REF]Hendry et al. 2021). To understand the geological meaning of seismic reflectors, the integration of sedimentologic and stratigraphic description with a physical characterisation of rocks is essential.

To establish a correlation between outcrop data and seismic data, a 1D synthetic seismic modelling is introduced as a valuable method used to generate seismic sections for outcrops based on ultrasonic and petrophysical measurements of samples collected from outcrops [START_REF] Zeller | Sequence architecture and heterogeneities of a field-Scale Vaca Muerta analog (Neuqu´en Basin, Argentina) -from outcrop to synthetic seismic[END_REF]Kleipool et al. 2017;Jafarian et al. 2018). However, the petrophysical properties obtained at sample scale are mainly influenced by microstructures while the influence of larger heterogeneities (fractures, stylolites, karst) is not considered. The analogue outcrops fill the gap caused by seismic resolution limitations and upscaling challenges, resulting in reduced subsurface uncertainties [START_REF] Mascolo | Seismic modelling of outcrop carbonate systems: an application to the Cretaceous platform-to-basin system of the Maiella Mountain (central Apennines, Italy)[END_REF]Hendry et al. 2021).

To improve the interpretation of seismic data in terms of facies and reservoir properties, we propose an integrated workflow based on geological, acoustic, and petrophysical characterization of a carbonate outcrop. This workflow is initially assessed on a French carbonate platform known as the "Oolithe Blanche" formation, which exhibits a well-exposed outcrop in Massangis Quarry, Burgandy, southeast of the Paris Basin. This formation is found throughout the Paris Basin, at various depths, and represents the preferred target for geothermal doublets in the Ile-de-France region.

Then, the workflow is applied on a large-scale analogue outcrop in Lebanon, located in Kfarhelda in the northern part of the country, by combining sedimentological and petrographic characterization with geophysical and petrophysical measurements. We focus on the Cenomanian -Turonian carbonate platform presenting a shallow marine platform deposited in prograding carbonate-ramp setting. This platform is known as the Sannine and Maameltain formations.

Sedimentologic and acoustic investigations are integrated with petrophysical measurements to generate a synthetic seismogram for the studied outcrop. The constructed synthetic seismic trace is then used to compare the geological information from the outcrop with the available seismic data. Seismic interpretation is also supported by seismic facies and attribute analysis. Pichon & Gaulier 1988;Hawie et al. 2013a;Nader 2014;[START_REF] Wood | Rethinking post-Hercynian basin development: Eastern Mediterranean Region[END_REF].

Objectives of the research

Considering the current context, this thesis aims to give answers to several questions by achieving the following objectives:

-Synthesize the geological and sedimentological data of Lebanon leading to a comprehensive understanding of the geological characteristics of the Cenomanian -Turonian carbonate platform.

-Assess the developed approach on the "Oolithe blanche" fm., a shallow marine carbonate platform outcropping in Massangis Quarry, France. This aims to understand the influence of facies variation and diagenetic history on the acoustic signal of rocks and the generation of seismic reflectors.

-Integrate the data collected from the field work on Kfarhelda outcrop in northern Lebanon to conduct a comprehensive characterization of the sedimentologic, petrophysical, and petrographic properties of this carbonate platform.

-Improve the interpretation of a 2D onshore seismic profile located northern Lebanon by conducting seismic facies and seismic attributes analysis.

-Correlate outcrop data with the interpreted onshore seismic data using synthetic seismic modelling. This aims to identify the seismic signature of stratigraphic sequences.

Organization of the dissertation

This thesis manuscript is organized in six chapters: In the last two decades, research projects provided substantial information about the sedimentological and stratigraphic characteristics of the northern part of the Levant Basin (Nader and Swennen 2004;Nader et al. 2006;Nader et al. 2007;Nader 2011;Hawie et al. 2013a;[START_REF] Hawie | Tectono-stratigraphic evolution of the northern Levant Basin (offshore Lebanon)[END_REF][START_REF] Bou Daher | Depositional environment and source rock characterisation of organic-matter rich Upper Turoniane-Upper Campanian carbonates, Northern Lebanon[END_REF][START_REF] Ghalayini | Impact of Cenozoic strike-slip tectonics on the evolution of the northern Levant Basin (offshore Lebanon)[END_REF]Hawie et al. 2015;[START_REF] Bou Daher | 3D thermal history and maturity modelling of the Levant Basin and its eastern margin, offshoreonshore Lebanon[END_REF]Nader et al. 2016). These studies contribute to understanding the tectonic and stratigraphic evolution of the Mesozoic and Cenozoic sedimentary strata onshore Lebanon.

The Jurassic -Cretaceous carbonate platform, covering much of the Eastern Mediterranean region, and prevailing onshore Lebanon is still poorly understood in terms of its stratigraphy and depositional history. Several authors approach this topic providing an updated review of the sedimentologic and stratigraphic evolution of the Cretaceous carbonate platform. The results propose new insights about the sedimentary facies' distribution, sequence stratigraphy, depositional environments, and diagenetic features predominating the studied formations (Hawie et al. 2013a;Nader 2014;[START_REF] Bou Daher | Depositional environment and source rock characterisation of organic-matter rich Upper Turoniane-Upper Campanian carbonates, Northern Lebanon[END_REF].

In this study, we focus on the Cenomanian -Turonian strata onshore northern Lebanon, representing shallow marine carbonate platform deposits. It is characterized by rudist-rich rudstones, representing the dominant frame-building organisms during the Cenomanian -Turonian ages [START_REF] Voigt | Biogeographic distribution of late Early to Late Cretaceous rudist-reefs in the Mediterranean as climate indicators[END_REF]. These rudists platforms are very well exposed in Batroun area (Fig. 2). The aim is to complete a field and microfacies investigation of the top part of Sannine formation and the Maameltain formation to describe the main lithologies and sedimentary features of the identified facies. This chapter is dedicated to the presentation of the sedimentary strata of northern Lebanon from the Jurassic onwards, with focus on the Cenomanian -Turonian sedimentary succession.

Understanding the sedimentologic and stratigraphic evolution of these strata makes it possible to constrain its depositional history and to complete a geological characterization of the carbonate platform. (After CNRS-Lebanon;Dubertret 1955;Nader 2011;Hawie et al. 2013a).

Geodynamic evolution of the Eastern Mediterranean and the Levant

Basin

The Eastern Mediterranean is a collage of fragmented tectonic terranes situated between the African, Arabian, and Anatolian plates (Fig. 1). The region has had a complex tectonic history since the breakup of Gondwana in the Early Mesozoic [START_REF] Harrison | A Model for the Plate Tectonic Evolution of the Eastern Mediterranean Region that Emphasizes the Role of Transform (Strike-Slip) Structures[END_REF]. The Eastern Mediterranean basin is considered a relic of the Mesozoic Tethys, and its formation is related to the Alpine Orogeny (Garfunkel 1998).

The formation of the Eastern Mediterranean is induced by three main rifting phases. The first phase occurred during the Late Permian (Fig. 3a) and is characterized by the opening of the Paleo-Tethys following the break-up of Pangea into Gondwana and Eurasia [START_REF] Robertson | Introduction: aspects of the geological evolution of the Eastern Mediterranean[END_REF][START_REF] Robertson | Palaeogeographic and palaeotectonic evolution of the Eastern Mediterranean Neotethys[END_REF]. The second phase occurred in the Late Triassic (Fig. 3b) and resulted in the formation of the Neo-Tethys that separated Gondowana into North-Gondowana and Africa (Dercourt et al. 1986).

The rifting is associated with widespread volcanism and pelagic sediments [START_REF] Hsü | Genesis of the Tethys and the Mediterranean, Initial Reports of the Deep Sea Drilling Project[END_REF]. The third and most significant rifting phase occurred during the Early Jurassic (Fig. 3c) propagating in NW-SE direction as Pangea split into northern and southern continents. The activity is followed by subsidence and formation of the deep marine Levant Basin, the Tauride Block, and the Eratosthenes Seamount [START_REF] Garfunkel | Permian-early Mesozoic tectonism and continental margin formation in Israel and its implications for the history of the eastern Mediterranean[END_REF]Garfunkel 1998).

During the Late Jurassic -Early Cretaceous, the eastward movement of Africa caused the detachment of micro-continents towards Eurasia (Fig. 3d), while the Neo-Tethyan oceanic crust experienced passive margin subsidence [START_REF] Hsü | Genesis of the Tethys and the Mediterranean, Initial Reports of the Deep Sea Drilling Project[END_REF]. In the Late Cretaceous (Fig. 3e), the Eastern Mediterranean was an area of continental collision between Africa and Eurasia [START_REF] Biju-Duval | Structure and Evolution of the Mediterranean Basins, Initial Reports of the Deep Sea Drilling Project[END_REF] resulting in a northward dipping subduction zone in the Levant area [START_REF] Robertson | Overview of the Palaeozoic-Neogene evolution of Neotethys in the Eastern Mediterranean region (southern Turkey, Cyprus, Syria)[END_REF]. The obduction of ophiolites onto the Arabian platform led to the exposure of this rock unit in NW Syria and Cyprus (Al [START_REF] Abdalla | Late Cretaceous to Cenozoic tectonic evolution of the NW Arabian platform in NW Syria[END_REF].

In the Early Cenozoic, a major folding stage and basin inversion (Syrian Arc Fold Belt) caused the inversion of major normal faults into asymmetric folds near the Levant margin and further inland (Hawie et al. 2013a). From the late Eocene onwards, the up-doming of the Afar plume marked the initiation of the Red Sea rifting (Bellahsen et al. 2003). By the Early-Mid Miocene, the rifting propagated NNW towards the Mediterranean Sea causing the separation of the African and Arabian plates along the Levant Fracture System (LFS). Transpressive movement along the LFS resulted in the uplift of Mount Lebanon [START_REF] Inati | Lithospheric architecture of the Levant Basin (Eastern Mediterranean region): A 2D modeling approach[END_REF].

Sedimentologic and stratigraphic background

The geological and stratigraphic evolution of Lebanon is described by several authors (Dubertret 1955(Dubertret , 1975;;Saint-Marc 1972, 1974;Beydoun 1977;Walley 1997Walley , 1998;;Nader 2000;Nader and Swennen 2004;[START_REF] Hawie | Tectono-stratigraphic evolution of the northern Levant Basin (offshore Lebanon)[END_REF]Nader 2014). The current structure and onshore geology of Lebanon is the result of successive onshore tectonic deformations.

Figure 4 shows the chronostratigraphic chart of onshore north Lebanon with the main formations from the Jurassic onwards. The oldest outcropping rock unit in Lebanon is the Lower Jurassic dolostone (Nader 2011). The Triassic is inferred to correlate with units identified in adjacent countries forming a 2000 m-thick unit of carbonates, clastics, and evaporites deposited in an environment similar to that of the Early Jurassic (Nader and Swennen 2004).

During the Jurassic, shallow-marine conditions prevailed resulting in the deposition of a 1500 m-thick carbonate succession deposited in platform setting (Renouard 1955;Walley 1997).

The prevailing large carbonate shelf in Lebanon during the Mid-Jurassic, is favoured by postrift subsidence of the eastern Levant and Palmyra basins and a global sea-level rise (Nader 2014). This leads to the deposition of Kesrouane formation characterized by a thick dolostone unit, overlain by a thick unit of massive fine-grained limestones and dolostones with marl intercalations at its base (Dubertret 1955;Renouard 1955;[START_REF] Collin | Middle and Upper Jurassic stratigraphy and sedimentary evolution of Lebanon (Levantine margin): palaeoenvironmental and geodynamic implications[END_REF].

The Bhannes fm is 50 to 150 m thick and consists of basaltic and volcanic deposits with marls and rare limestone intercalations, depositing as a result of a global sea-level fall and intense tectonic activity and volcanism during the Late Jurassic [START_REF] Saint-Marc | Le passage Jurassique -Crétacé et le Crétacé inférieur de la région de Ghazir (Liban central)[END_REF]Walley 1997).

The Bikfaya fm is a 60 m-thick cliff-forming limestone unit (Dubertret 1955), consisting of locally dolomitized grey limestones with chert nodules (Dubertret 1975;Nader et al. 2007). It is deposited in shallow carbonate platform setting favoured by marine transgression and regional uplift during Late Kimmeridgian -Tithonian.

The overlying Salima fm consists of ferruginous oolitic limestones interbedded with marls, clays, and sandstones (Dubertret 1955). It has a variable thickness reaching 200 m near Beirut, while it thins to few meters or complete absence in some areas northern Lebanon (Nader et al. 2007;Nader 2014). [START_REF] Clark | The larger benthic foraminifera and stratigraphy of the Upper Jurassic/Lower Cretaceous of Central Lebanon[END_REF] discuss that the Salima fm deposited in shallow water conditions with terrigenous influence resulting from regional uplift above eustatic sea-level rise.

The Late Jurassic -Early Cretaceous period is characterized by regression and local emergence in northern Lebanon. As a result, the Jurassic -Cretaceous boundary is marked by an erosional unconformity in which the Berriasian rock units are absent from the Levant margin (Dubertret 1975;Nader et al. 2007). The Chouf fm overlies this unconformity and consists of ferruginous sandstone deposited in a fluvial to deltaic environment with some organic-rich shales. The Chouf fm is 300 m thick at central Lebanon and thins to few tens of meters to the north (Dubertret 1975).

The overlying Abeih fm (Barremian to Early Aptian) is a variable unit with a maximum thickness of 170 m in central Lebanon. It consists of fossiliferous limestones, marls, and sandstones. Its lithology changes from claystone and sandstone in the lower part, to carbonate rocks in the upper part (Dubertret 1955;Walley 1997).

Marine transgression prevailed during the Early Aptian leading to the deposition of Mdairej fm (50 m-thick), a massive clay forming limestone unit deposited in shallow marine shelf environment (Dubertret 1963;Walley 1997). It consists predominantly of wackestone with small scale rudists (Nader 2014). The Late Aptian is characterized by a return to terrigenous clastic sediments and clays, known as Hammana fm, deposited in a restricted tidal to supratidal environment (Nader 2000;[START_REF] Hawie | Tectono-stratigraphic evolution of the northern Levant Basin (offshore Lebanon)[END_REF]. Its thickness ranges between 150 and 185 m representing a gradual transition from terrigenous sediments to marly and dolomitic limestones (Saint-Marc 1974;[START_REF] Doummar | Sedimentology and diagenesis of the Albian rock sequence (Upper Hammana-Lower Sannine Formations)[END_REF]).

In the Cenomanian, volcanism ceased, and a major marine transgression followed resulting in the deposition of carbonate platforms across Lebanon known as the Sannine and Maameltain formations [START_REF] Mouty | The geological study of the Palmyridian chain using ideal geological sections for exploration purposes and geological survey. General Establishment of Geology and Mineral Resources, Syrian Ministry of Petroleum and Mineral Resources, Damascus, Syria[END_REF]Walley 1997).

The Upper Cretaceous is characterized by chalky and marly limestones deposited in deep marine conditions known as Chekka fm with a thickness between 200 and 600 m (Dubertret 1955;Brew et al. 2001). Early to Mid-Eocene deposits of chalky and marly limestones are recognized in northern Lebanon, and the Miocene rocks overlies unconformably over the Eocene formation [START_REF] Müller | Revised stratigraphy of the Upper Cretaceous and Cenozic series of Lebanon based on nannofossils[END_REF]Nader 2014). The Lower Miocene is marked by a regional hiatus in the Levant region with two transgressive sequences, during the Burdigalian and Langhian, capping strata of lower ages (Hawie et al. 2015). Walley 1997;[START_REF] Hawie | Tectono-stratigraphic evolution of the northern Levant Basin (offshore Lebanon)[END_REF]Nader et al. 2016).

Intense tectonic activity induced the uplift of Mount Lebanon toward the Late Miocene [START_REF] Hawie | Tectono-stratigraphic evolution of the northern Levant Basin (offshore Lebanon)[END_REF]. This favoured the sedimentation on the Levant margin in which continental deposits are recognized in northern Lebanon consisting of marls, algal limestones, and conglomerate intercalations (Hawie et al. 2013a). Northern Lebanon is dominated by marine deposits forming rhodalgal build-ups dated from the Serravallian to Tortono-Messinian [START_REF] Boudagher-Fadel | Stratigraphy, paleoenvironment and paleogeography of Maritime Lebanon: a key to Eastern Mediterranean Cenozoic history[END_REF].

The Early Pliocene is marked by an important transgression as sea invasion covered the lowlying areas in Lebanon and resulted in the deposition of sandy and silty, nannofossil-rich deposits (Nader 2014). In northern Lebanon, the marine Early Pliocene unit unconformably overlies the Late Miocene continental deposits [START_REF] Müller | Revised stratigraphy of the Upper Cretaceous and Cenozic series of Lebanon based on nannofossils[END_REF]. Finally, Quaternary deposits are recognized in northern Lebanon with persisting fluvial and lacustrine environments (Dubertret 1955;[START_REF] Elias | Le chevauchement de Tripoli-Saida: Croissance du Mont-Liban et risque sismique[END_REF].

2.4. The Cenomanian -Turonian platform in north Lebanon: Sannine and

Maameltain formations

The Sannine fm is 600 m-thick and consists of massive limestones and dolostones with cherts and thinly bedded marls (Saint-Marc 1974;Nader 2014). It is recognized for the lateral variation of prevailing depositional environments into (1) reefal and lagoonal settings inland to the east with channels and patch reefs, and (2) subtidal to deep marine settings westward (coastal area) (Noujaim 1977;Nader et al. 2006). Saint-Marc (1974) The Cenomanian carbonates in Lebanon represent an important segment of the regional platform. Nader et al. (2006) propose a ramp depositional model of the Cenomanian platform carbonates of central northern Lebanon, in which the dolostones and the marly limestones are deposited in supratidal environments while the thick-massive bioclastic wackestone to packstone facies are deposited in shallow inner ramps. These deposits are often associated with the presence of local paleo-channels within the limestone beds (Walley 1998;Nader et al. 2006).

The Turonian is characterized by the deposition of massive to thinly bedded limestones and marly limestones (200 -300 m-thick) known as the Maameltain formation. It is dated based on the appearance of Turonian Ammonites or the rudist bivalve Hippurites (Dubertret 1975;Noujaim 1977;Walley 1997). The Turonian -Senonian boundary is bound by unconformity (Nader 2000;[START_REF] Müller | Revised stratigraphy of the Upper Cretaceous and Cenozic series of Lebanon based on nannofossils[END_REF].

The Turonian carbonate platform represents an important marker indicating the shallowing of the prevailing depositional environment (Dubertret 1975;Noujaim 1977). Hawie et al. (2013a) describe the Cenomanian -Turonian carbonate platform of northern Lebanon to have deposited in a prograding ramp setting. The Turonian carbonates consist of mudstone dominated facies, bioclastic packstone to grainstone units, rudist rich rudstones and fine crystalline dolomite facies. This sedimentary sequence is interpreted to have been deposited in outer ramp to shallow marine environment (Hawie et al. 2013a).

Kfarhelda outcrop

In this PhD thesis, we study an outcropping Cenomanian -Turonian carbonate platform in Kfarhelda, northern Lebanon. The age of this sedimentary succession is well constrained by sedimentological and biostratigraphic data (Nader 2000;Nader et al. 2006;Hawie et al. 2013a).

Our study focuses on the upper part of the Sannine formation consisting of medium to thick bedded limestone, and the rudist rich shallow marine carbonates of Maameltain formation. The outcropping Turonian carbonates are interpreted to consist of massive packstone to grainstone beds with chert bands followed by a unit of mud supported textures. Overlying this unit are the grain-supported rudist rich facies, followed by dolomitized beds and brecciated packstone units [START_REF] Hawie | Tectono-stratigraphic evolution of the northern Levant Basin (offshore Lebanon)[END_REF]).

The previously discussed references provide a geological and sedimentological background explaining the deposition of the Cenomanian -Turonian carbonate platform in northern Lebanon. Nonetheless, a detailed sedimentological characterization of this platform requires a high-resolution field investigation of beds. This includes lithology and texture description of beds, as well as a comprehensive understanding of the spatial distribution of sedimentary facies.

Additionally, coupling between the macrofacies and microfacies analysis provides a detailed sedimentary characterisation of the Cenomanian -Turonian shallow marine carbonate platform located in north Lebanon.

Chapter 3: Methodology 3. Methodology

Introduction

Carbonate rocks display heterogeneities at various scales: microscale (mm), outcrop scale (1 -10 m), and seismic scale (100's m). Reservoir modelling is based on investigating carbonate heterogeneities at tens of meters scale, assuming the properties to be homogeneous under this scale. Conversely, investigating the rocks at sample scale uncovers heterogeneities in microstructures controlled by a range of factors including density, porosity, and pore type [START_REF] Anselmetti | Sonic velocity in carbonates -A combined product of depositional lithology and diagenetic alterations[END_REF][START_REF] Baechle | Effects of microporosity on sonic velocity in carbonate rocks[END_REF].

Several studies investigated the influence of microstructures (sedimentary and/or diagenetic), analysed from rock samples, on the acoustic and petrophysical properties of rocks (Fournier and Borgomano 2007;[START_REF] Baechle | Effects of microporosity on sonic velocity in carbonate rocks[END_REF][START_REF] Brigaud | Acoustic Properties of Ancient Shallow-Marine Carbonates. Effects of Depositional Environments and Diagenetic Processes (Middle Jurassic, Paris Basin, France)[END_REF][START_REF] Soete | Acoustic properties in travertines and their relation to porosity and pore types[END_REF][START_REF] Zeller | Sequence architecture and heterogeneities of a field-Scale Vaca Muerta analog (Neuqu´en Basin, Argentina) -from outcrop to synthetic seismic[END_REF]Kleipool et al. 2017;Jafarian et al. 2018;Adelinet et al. 2019;Bailly et al. 2019a;[START_REF] Reijmer | Petrophysics and sediment variability in a mixed alluvial to lacustrine carbonate system (Miocene, Madrid Basin, Central Spain)[END_REF]) including work on carbonates from central and northern Lebanon (Salah et al. 2020a;[START_REF] Salah | Petrophysical and acoustic assessment of carbonate rocks, Zahle area, central Lebanon[END_REF]). Nonetheless, acoustic velocities vary with upscaling in response to different geological heterogeneities (Boadu and Long 1996;Lubbe and Worthington 2006;Bailly et al. 2019b).

For instance, acoustic velocity measured at both plug and seismic scales is not representative of sedimentary structures observed on the outcrop. As a result, determining the outcrop scale heterogeneities remains a critical approach. In this context, outcrops are presented as analogues for subsurface reservoirs allowing the direct correlation between outcrop structures and petrophysical properties through geophysical methods. This allows to evaluate the impact of outcrop-scale sedimentary and diagenetic features on the variation of petrophysical and acoustic properties of rocks.

This chapter highlights the methodology used to characterize the Cenomanian -Turonian carbonate platform in Kfarhelda using an integrated workflow. We combined sedimentological, acoustic, petrophysical, and synthetic seismic analysis on the outcrop to understand the impact of geological characteristics on the acoustic and seismic properties of rocks. The chapter includes three first sections: (1) sedimentologic and acoustic data acquired through fieldwork,

(2) petrophysical analysis of collected samples, and (3) statistical analysis and synthetic seismic modelling of acquired data. These three steps have been tested on Massangis Quarry study site (results presented in Chapter 4) and then improved and applied on the Cenomanian -Turonian carbonate platform in Kfarhelda, Lebanon.

A last step of the methodology is presented here, corresponding to the seismic interpretation of the 2D onshore data calibrated with the field study. This last step is applied only to the Lebanese study case, thanks to the Lebanese Petroleum Administration who provided access to the 2D onshore seismic profile acquired in 2013.

Sedimentologic and acoustic data acquired through fieldwork

A detailed sedimentary description is completed for the studied outcrops including lithology and texture description of each bed. The depositional-textural classification of rocks is based on [START_REF] Dunham | The chronostratigraphic significance of seismic reflections along the Bahamas Transect[END_REF] classification, bioclastic content, and outcropping diagenetic features. In addition, representative samples are collected for petrographic analysis (thin sections studied under polarized light), and the description of texture, porosity, and diagenetic phases is completed based on [START_REF] Dunham | The chronostratigraphic significance of seismic reflections along the Bahamas Transect[END_REF] and [START_REF] Choquette | Geologic Nomenclature and Classification of Porosity in Sedimentary Carbonates[END_REF] classifications.

Measuring acoustic wave properties on rocks is a simple technique characterized by its fast, non-destructive, and economical approach [START_REF] Xing | Review of Research Process and Application of Acoustic Wave Testing Technology for Rock[END_REF]). P-wave velocity is acquired directly on the rock surface using Pundit PL-200 device with 40 kHz frequency (Fig. 5). The waves propagate through the rock mass between the transmitter and the receiver.

The first arrival time is picked to ensure precise velocity measurements and minimize the wave scattering and attenuation (Jafarian et al. 2018). Velocities are determined by dividing the arrival time to the spacing between the sensors (Matonti et al. 2015;[START_REF] Soete | Acoustic properties in travertines and their relation to porosity and pore types[END_REF]. The frequency used to measure acoustic velocities is dependent on the rock mass volume according to the following equation (eq. 1):

λ = v f eq. 1
where λ is wavelength in meter, v is velocity in m/s, and f is frequency in kHz.

Measuring P-wave velocity at seismic scale requires a very low frequency (10 -80 Hz) to obtain a wavelength of tens of meters [START_REF] Hart | Acquisition and Processing, In: An Introduction to Seismic Interpretation[END_REF]). On the contrary, measuring P-wave velocity on plug scale (around 10 cm length) requires a very high frequency (e.g., 500 kHz or 1 MHz) to obtain a wavelength of millimetre to centimetre scale [START_REF] Soete | Acoustic properties in travertines and their relation to porosity and pore types[END_REF]Kleipool et al. 2017;Bailly et al. 2019a).

In this study, to ensure enough number of cumulative waves for a representative velocity value at outcrop scale, the spacing (L) between the emitter and the receiver is maintained constant at around 40 cm. This implies a wavelength between 5 and 15 cm for a 40 kHz frequency and velocity values between 2000 and 6000 m/s [START_REF] Jeanne | Multiscale seismic signature of a small fault zone in a carbonate reservoir: relationships between VP imaging, fault zone architecture and cohesion[END_REF]Matonti et al. 2015;Bailly et al. 2019b). The distance between the emitter and the receiver is slightly adjusted at measuring points with irregular rock surfaces (cracks, fractures, karst).

Laboratory measurements

Samples are collected from the outcrop, and depending on their size, they are cut into cubes to acquire physical properties. The density and porosity values of rock samples are calculated using triple-weight method by measuring sample mass in dry condition, fluid-saturated condition, and fluid-saturated submerged in the saturating fluid (Fig. 6). First, the samples are dried in oven at 60 °C for 24 hours to measure the dry mass (mdry). Then, the samples are placed in a desiccator connected to a pump to ensure vacuum conditions for a minimum of eight hours (Fig. 6a). The desiccator is connected at the same time to an Erlenmeyer filled with de-mineralized water. The water is routed to the desiccator and the samples are soaked for minimum 12 hours. Finally, the submerged mass (msub) and saturated mass (msat) are measured (Fig. 6b), and the porosity, bulk density, and mineral density are calculated based on the following equations (eq. 2,3,4):

Porosity = 𝑀 𝑠𝑎𝑡 -𝑀 𝑑𝑟𝑦 𝑀 𝑠𝑎𝑡 -𝑀 𝑠𝑢𝑏 × 100 (2) Bulk density (ρ𝑏𝑢𝑙𝑘) = 𝑀 𝑑𝑟𝑦 𝑀 𝑠𝑎𝑡 -𝑀 𝑠𝑢𝑏 (3) Mineral density (ρ𝑚𝑖𝑛) = 𝑀 𝑑𝑟𝑦 𝑀 𝑑𝑟𝑦 -𝑀 𝑠𝑢𝑏 (4)

Synthetic seismic modelling

The synthetic seismogram is an essential tool used to correlate outcrop data and seismic data.

The construction of a synthetic seismogram requires a thorough understanding of the petrophysical characteristics of the identified facies (Jafarian et al. 2018). The seismic response is primarily controlled by the acoustic impedance (AI) representing the product of P-wave velocity (Vp) and bulk density (ρbulk) [START_REF] Stafleu | Seismic models of outcrops as an aid in seismic Interpretation[END_REF]. The calculation of AI values is based on Pwave velocities acquired directly on the outcrop and density values measured in the laboratory.

The computed acoustic impedance is used to calculate the reflection coefficient (RC) (eq. 5). A zero-phase Ricker wavelet is used, and the frequency is chosen based on the desired resolution.

The zero-phase Ricker wavelet is the second derivative of the Gaussian function characterized by its asymmetrical amplitude spectrum, which is similar to the attenuation feature of seismic wave propagation (Fig. 7; Wang 2015).

The synthetic wavelet is convolved with the RC values calculated for the entire section to generate a 1D synthetic seismogram [START_REF] Stafleu | Seismic models of a prograding carbonate platform: Vercors, south-east France[END_REF]).

RC =

𝐴𝐼 2 -𝐴𝐼 1 𝐴𝐼 2 + 𝐴𝐼 1

(5)

The final simulated seismic trace is described by the convolutional model (eq. 6) assuming the removal of all amplitude effects except the R0 (Rekoske and Hicks 1992).

T(t) = R0(t) × w(t) (6)
where T(t) is seismic trace, R0(t) is reflection coefficient series, and w(t) is the wavelet.

The generated synthetic seismogram presents zero-offset seismic traces, representing the vertical variation of AI and RC values. The main objective of this approach is to investigate the ability of the synthetic seismogram to resolve outcrop observations [START_REF] Janson | Seismic expressions of a Miocene prograding carbonate margin, Mut Basin, Turkey[END_REF]Kleipool et al., 2017;Jafarian 2018). This allows the comparison between the outcrop geological data and the onshore 2D seismic profile using the synthetic seismogram. The resolution of the generated synthetic seismic trace is determined based on equations 1 and 7:

Resolution = 𝑊𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ (𝜆) 4 (7)

Calibration of 2D seismic data with 1D seismic modelling

The calibration of 2D seismic data with the 1D seismic modelling has been only developed for the Lebanese case study. Therefore, the methodology developed for this step is presented using the data available for Kfarhelda outcrop.

The 2D seismic profile SLEB-2D-01-13 with EW orientation (Fig. 2) has a 44 km linear distance from Batroun coastal city to Ainata village. It was acquired in 2013 using road based Vibroseis units and processed by Spectrum Geo Ltd. following Kirchhoff Pre-stack Time Migration (PSTM). PSTM is run with velocities smoothed over 2 km, 1 km, and 500 m intervals when appropriate for the final pass of velocity analysis using CDP gathers, constant velocity stacks, and contoured semblance displays.

The interpretation of the profile is done at the Lebanese Petroleum Administration using Petrel software to identify major seismic horizons. The interpretation of seismic packages and their relative bounding surfaces is completed based on seismic stratigraphic concepts correlating genetically related sedimentary strata at depth (Vail et al. 1977;Mitchum 1977).

Determining the properties of rocks at seismic scale can be also achieved using seismic refraction method in which the field seismic data and outcrop data are acquired in the same location, on the same 2D line. In this study, acquiring field seismic data was not possible, however, we present here the methodology of field seismic acquisition that can be applied in an ideal case to support the proposed workflow.

Compressional waves are generated from a source on the ground surface (e.g., a sledgehammer) and travels down through the ground and back up to the sensors aligned on the land surface (geophones). Velocity variations and depth of layers are calculated from the measured distances and the seismic travel times acquired in the field [START_REF] Adelinet | Seismic-refraction field experiments on Galapagos Islands: A quantitative tool for hydrogeology[END_REF].

The processing of the acquired data includes picking first break arrivals of P-wave velocity to construct travel time curves, which are used to generate an initial velocity model with fixed number of layers (n = 20). Using this velocity model, the tomography iterative process is applied to compare the calculated travel times with the measured travel times and modify the model to minimize the difference between the two values. In the last step of the tomography process, a global Root Mean Square (RMS) error is calculated to assess the quality of the workflow [START_REF] Zhang | Nonlinear refraction and reflection travel time tomography[END_REF][START_REF] Adelinet | Seismic-refraction field experiments on Galapagos Islands: A quantitative tool for hydrogeology[END_REF].

Finally, using a seismic processing software or programming tool, the pre-stack data corresponding to the location of the studied outcrop are extracted by specifying the desired seismic traces and gather shots, and exporting them as separate dataset [START_REF] Zhao | Automatic events extraction in pre-stack seismic data based on edge detection in slant-stacked peak amplitude profiles[END_REF][START_REF] Hart | Acquisition and Processing, In: An Introduction to Seismic Interpretation[END_REF].

Massangis test case study 4.1. Introduction

Seismic imaging methods have achieved considerable advancements in the last decade with the widespread adoption of 3D and 4D imaging techniques. Seismic reflections result from disparities in acoustic impedance, the product of sonic velocity and density (Sheriff 1977). Even with the incorporation of new techniques, the acoustic properties of carbonate rocks remain poorly comprehended.

Carbonate rocks exhibit significant variations in their petrophysical properties, which are related to their primary microstructures. The metastable nature of carbonates enhances diagenetic processes leading to the development of secondary microstructures with spatial changes in porosity and pore structures [START_REF] Bathurst | Carbonate Sediments and their diagenesis[END_REF]Fournier and Borgomano 2007;Teillet et al. 2020). Nonetheless, the density variation in carbonate rocks remain relatively low [START_REF] Brigaud | Acoustic Properties of Ancient Shallow-Marine Carbonates. Effects of Depositional Environments and Diagenetic Processes (Middle Jurassic, Paris Basin, France)[END_REF]). Consequently, rock velocity serves as a key parameter for constraining the geological origin of seismic reflectors and correlating the reflectors to their sedimentologic equivalent.

Synthetic seismic modelling is presented as a helpful tool to generate seismic sections for outcrop analogues. This allows to understand the stratigraphic and sedimentologic origin of seismic reflectors, thereby improving the interpretation of seismic data [START_REF] Zeller | Sequence architecture and heterogeneities of a field-Scale Vaca Muerta analog (Neuqu´en Basin, Argentina) -from outcrop to synthetic seismic[END_REF]Kleipool et al. 2017;Bailly et al. 2019a). In this study, we propose a combined sedimentologic and petroacoustic approach to the "Oolithe Blanche" equivalent located in Massangis quarry, to understand the impact of sedimentologic and diagenetic heterogeneities on the evolution of rocks' properties.

The Massangis quarry is located 150 km southeast of Paris and reveals Middle to Upper Bathonian carbonates. These rocks are interpreted to have been deposited in tidal to sub-tidal and shoreface depositional environments. The quarry has been extensively studied for its importance as a geothermal reservoir representing an analogue for the "Oolithe Blanche" subsurface reservoir in the Paris Basin [START_REF] Mougenot | Seismic imaging of a carbonate reservoir; the Dogger of the Villeperdue oil field, Paris Basin, France[END_REF][START_REF] Brigaud | Characterization and origin of permeability-porosity heterogeneity in shallow-marine carbonates: from core scale to 3D reservoir dimension (Middle Jurassic, Paris Basin, France)[END_REF][START_REF] Regnet | Influence of microporosity distribution on the mechanical behavior of oolithic carbonate rocks[END_REF].

A thorough acoustic characterization is completed for a 2D section, using a portable device (Pundit PL-200), by measuring P-wave and S-wave velocities in both horizontal and vertical directions. In addition, a detailed sedimentological description is realized at each measuring point to complete a high-resolution facies characterization. The measured P-wave velocities are used to generate a 2D synthetic seismic trace at high frequency (5 kHz) to highlight major seismic reflectors. The main objective of this study is to determine the relative impact of facies variation and diagenetic processes on the acoustic properties of rocks, therefore, the generation of seismic reflectors.

4.2. Geological background, sedimentological, and stratigraphic framework 4.2.1. Geological and sedimentological setting

The Paris Basin is an intraplate flexural basin covering a large part of northern France [START_REF] Pomerol | Paleogeographic and structural evolution of the Paris Basin, from the Precambrian to the present day, in relation to neighboring regions, Geologie En Mijnbouw[END_REF][START_REF] Mégnien | Synthèse géologique du Bassin de Paris, I, Stratigraphie et paléogéographie[END_REF]). The basin is characterized by an ongoing Meso-Cenozoic subsidence originating from the long-term thermal subsidence, and several short-lived tectonic events related to the local deformations of the Eurasian plate (Fig. 8a, [START_REF] Robin | Time and space scales of tectonic control on a flexural intracratonic basin; the Paris Basin[END_REF][START_REF] Briais | Response of a low-subsiding intracratonic basin to long wavelength deformations: the Palaeocene-early Eocene period in the Paris Basin[END_REF]. This resulted in deformational patterns and transgressive -regressive cycles, as well as major deformational unconformities [START_REF] Robin | Stratigraphic measurement of deformation; application to Jurassic evolution of the Paris Basin[END_REF][START_REF] Guillocheau | Meso-Cenozoic geodynamic evolution of the Paris Basin: 3D stratigraphic constraints[END_REF].

The Massangis quarry is situated 150 km southeast Paris in the south-eastern part of the Paris Basin (Fig. 8a). During the Bathonian, the Paris Basin was an epicontinental sea, at subtropical latitudes (28 -32°) open to the Atlantic, Tethys, and Arctic oceans [START_REF] Thierry | Middle Callovian, map 9[END_REF][START_REF] Brigaud | Characterization and origin of permeability-porosity heterogeneity in shallow-marine carbonates: from core scale to 3D reservoir dimension (Middle Jurassic, Paris Basin, France)[END_REF]. The Massangis quarry is characterized by Mid to Late Bathonian (167 My, Middle Jurassic) limestones and is extensively studied as reservoir analogue for the "Oolithe Blanche" formation [START_REF] Purser | Early diagenesis and the preservation of porosity in Jurassic limestones[END_REF][START_REF] Purser | Plates-formes carbonatées exemple du Jurassique moyen du Bassin de Paris, Dynamique et méthodes d'étude des bassins sédimentaires[END_REF][START_REF] Makhloufi | Impact of sedimentology and diagenesis on the petrophysical properties of a tight oolitic carbonate reservoir. The case of the Oolithe Blanche Formation (Bathonian[END_REF][START_REF] Regnet | Influence of microporosity distribution on the mechanical behavior of oolithic carbonate rocks[END_REF]. The subsurface equivalent "Oolithe Blanche" interval is believed to be about 1500 m deep towards the centre of the Paris Basin [START_REF] Thomas | Contribution of drone photogrammetry to 3D outcrop modeling of facies, porosity, and permeability heterogeneities in carbonate reservoirs (Paris Basin, Middle Jurassic)[END_REF].

Stratigraphy and facies definition

Massangis quarry consists of three main parts: lower, middle, and upper parts [START_REF] Loreau | Géométrie et couleur des couches dans l'oolithe blanche de Massangis (Yonne)[END_REF][START_REF] Makhloufi | Impact of sedimentology and diagenesis on the petrophysical properties of a tight oolitic carbonate reservoir. The case of the Oolithe Blanche Formation (Bathonian[END_REF]. The lower and middle parts are identified as "roche de

Valanges" and "roche de Massangis" respectively, and both belong to the "Oolithe Blanche" formation. The upper part is known as Comblanchien Limestones. In this study, we focus on the "Oolithe Blanche" in which the "roche de Valanges" is defined as Valanges fm and "roche de Massangis" is defined as Massangis fm (Fig. 8b). texture [START_REF] Dunham | The chronostratigraphic significance of seismic reflections along the Bahamas Transect[END_REF], bioclastic content, bioturbation intensity, early diagenetic features, and type of surface at bed contacts [START_REF] Vincent | Giant subaqueous carbonate dunes: a revised interpretation of large-scale oo-bioclastic clinoforms in the middle Jurassic of the Paris Basin and its implications[END_REF].

Previous works of

The macrofacies study is supported by microfacies analysis completed on five thin sections made from outcrop samples collected from the Valanges fm, and three thin sections from Massangis fm. The thin sections are impregnated with blue epoxy to visualize the pore space.

The composition of the samples is analysed by point-counting quantification of micritic grains (ooids, peloids), bioclasts, cement, and macro-and microporosity using JmicroVision Image analysis software, with a minimum of 500 counts per thin section. The results of the composition quantification are expressed in percentage [START_REF] Roduit | JMicroVision: Image analysis toolbox for measuring and quantifying components of high-definition images[END_REF][START_REF] Brigaud | Acoustic Properties of Ancient Shallow-Marine Carbonates. Effects of Depositional Environments and Diagenetic Processes (Middle Jurassic, Paris Basin, France)[END_REF].

Acoustic measurements

Acoustic velocities are measured directly on the outcrop using Pundit PL-200 device with 40 kHz S-wave transducers (sensors). The waves propagate through the rock between two sensors, one sensor is a transmitter and the other is a receiver. The first arrival time of acoustic waves is picked to ensure that the measurement is based on the fastest wave, allowing more precise velocity measurements with less than 5% error (Jafarian et al. 2018;Bailly et al. 2019b).

Velocities are determined by dividing the arrival time to the spacing between the sensors (Matonti et al. 2015;[START_REF] Soete | Acoustic properties in travertines and their relation to porosity and pore types[END_REF]. Velocities are acquired directly on the plane quarry faces. For velocity values between 1200 and 6000 m/s, using 40 kHz central frequency implies a wavelength between 3 and 15 cm (eq. 1).

The P and S-waves velocities are acquired both horizontally and vertically. A total of 1000 acoustic velocities are measured on the quarry wall for the studied 2D section on the uppermost part of the Valanges fm. The section is 12 m wide and 2.8 m high in which about 400 nodes are marked on the outcrop at 40 cm horizontal spacing and 20 cm vertical spacing (Fig. 9).

Velocities are not acquired for some points at the bottom of the section due to the irregularity of the ground surface. Similarly, velocity measurements are acquired on the 1D logs in the lower part of Massangis fm (3 logs). [START_REF] Brigaud | Acoustic Properties of Ancient Shallow-Marine Carbonates. Effects of Depositional Environments and Diagenetic Processes (Middle Jurassic, Paris Basin, France)[END_REF][START_REF] Brigaud | Characterization and origin of permeability-porosity heterogeneity in shallow-marine carbonates: from core scale to 3D reservoir dimension (Middle Jurassic, Paris Basin, France)[END_REF]. Since the Valanges outcrop is relatively small (12 x 2.8 m), no major density or facies variations are observed. Therefore, we consider a constant density value for the impedance calculation.

The 2D section is divided into 31 pseudo 1D vertical logs, and the synthetic seismic workflow is applied independently on each 1D log. The seismic response is primarily controlled by the acoustic impedance (AI), a product of P-wave velocity (Vp) and bulk density (ρbulk) [START_REF] Stafleu | Seismic models of outcrops as an aid in seismic Interpretation[END_REF]. The AI is calculated on the same grid dimension as the velocities. The computed AI values are used to calculate the reflection coefficients (RC) (eq. 5) using conventional SEG definition.

Results

Sedimentology and facies distribution

Valanges section

High-resolution facies analysis is completed on the Valanges section, including lithology and texture description of beds and identification of major diagenetic features. This description highlighted new characteristics for different facies compared to the lithofacies described in The distribution of high-resolution facies and the location of collected samples (M1 to M5) are described in Figure 10. The base of the section shows fine grainstone overlain by angular crossbedded grainstones with bivalves and ooids. This unit is around 1 m thick and capped by a hardground, representing a maximum regressive surface [START_REF] Thomas | Contribution of drone photogrammetry to 3D outcrop modeling of facies, porosity, and permeability heterogeneities in carbonate reservoirs (Paris Basin, Middle Jurassic)[END_REF]) at 1 -1.5 m elevation between 6 and 12 m width. Between 1 and 1.8 m elevation, we observe a unit of bioturbated and bioclastic grainstone from 0 to 6 m width. It is also identified between 8 and 12 m at around 1 m elevation, and at the top of the outcrop at around 2.5 m elevation.

This unit is followed by around 0.6 m-thick rudstone unit with bivalves, shells, and ooids.

However, the rudstone unit is absent to the left of the outcrop (0 -3 m width). It is characterized by bioturbations and stylolites at the top, at the limit of contact with the overlying grainstone, at around 1.6 -1.8 m elevation. The rudstone is followed by a thicker unit (around 2m) of flat cross-bedded grainstone with bivalves, and bioturbations at the top of the outcrop. The main difference between the two facies is the presence of bioturbations observed in F1b.

Above F1b we observe a grainstone unit with cross-bedding, crinoids, and bioclasts (F1d). The thickness of this unit increases laterally (westward), in which the beds observed between markers A and B (bioturbation markers) increases from 0.4 to 3 m (Fig. 11b).

Acoustic and petrophysical properties

Valanges section

The distribution of different velocities measured on the 2D Valanges outcrop are presented in Figure 12a. The picking of S-waves' first arrival was not possible in some cases resulting in a greater number of P-wave measurements. Additionally, vertical velocity measurements near stylolites (and fractures) appear to be slow, thereby are not representative. As a result, the number of measured horizontal velocities is greater than the number of vertical velocities.

Horizontal P-wave velocities range between 2120 and 5230 m/s, while vertical P-wave velocity is between 1512 and 4640 m/s. Additionally, the S-wave velocities measured horizontally range from 1190 to 2640 m/s, and the vertical velocity is between 1000 to 2400 m/s. P-wave velocities show a wide variation, and the vertical velocity values are lower than the horizontal velocity values.

The normal distribution of the measured velocities is illustrated in Figure 12b. At a given measuring point, for both vertical and horizontal measurements, the Vs value is approximately 50% of the Vp value. The Vp versus Vs plot (Fig. 12c) shows that Vp/Vs ratios are mostly between 1.9 and 2.2.

Figure 13 shows the velocity results obtained from the 2D Valanges section. The horizontal Pwave velocities show significant contrast between the bottom and top parts of the section.

Velocities are higher at the bottom of the section (between 4000 and 5000 m/s) whereas the top part show lower velocities centred around 3500 m/s. The horizontal S-wave velocities show similar distribution, while it is less clear for vertical P-and S-wave velocities. Finally, the porosity is estimated from thin sections using point-counting method and ranges between 7 and 19%.

Horizontal P-wave velocities range between 2550 and 5050 m/s, with a median value 4065 m/s.

Whereas vertical P-wave velocities are between 3035 and 5300 m/s and have a higher median value of 4500 m/s. S-wave velocities have median value of 1960 m/s for horizontal velocity, and 2180 m/s for vertical velocity. Vertical velocities measured at Massangis section are clearly higher than the ones measured at the Valanges outcrop. Two other types of calcite cement occur in the Valanges section: The first type is drusy cement consisting of mosaic calcite rhombs that increase in size towards the centre of voids spaces [START_REF] Flügel | Microfacies of Carbonate Rocks: Analysis, Interpretation and Application[END_REF]. The second type corresponds to syntaxial overgrowth consisting mainly of calcite rims on echinoderm grains [START_REF] Heinrich | Microscopic Petrography, McGraw-Hill series in the geological sciences[END_REF]). Such cement fabric has been illustrated for the Middle Jurassic carbonates of the Paris Basin [START_REF] Purser | Syn-sedimentary marine lithification of Middle Jurassic in the Paris Basin[END_REF][START_REF] Brigaud | Acoustic Properties of Ancient Shallow-Marine Carbonates. Effects of Depositional Environments and Diagenetic Processes (Middle Jurassic, Paris Basin, France)[END_REF]). The two cement types constitute together less than 7% of the total cement volume (Fig. 14,M1,M3). In addition, evidence of compaction is observed in grainstone facies (F2b) with grain-to-grain interpenetration (Fig. 14,M2). implies a resolution between 6 and 30 cm. This allows to distinguish the seismic reflectors at the studied scale.

4.5. Discussion 4.5.1. Facies and texture control on velocity

The distribution of velocity on the Valanges section shows that for both P-wave and S-wave velocity, the values of horizontal velocities are higher than those for the vertical velocities. This could be associated with the distribution of facies on the outcrop. Horizontally, the facies are homogenous, whereas they vary vertically with significant contrast in petrophysical properties.

Additionally, stylolite and karst features are observed on the outcrop in horizontal to subhorizontal planes. This can significantly disrupt the vertical propagation of waves and result in lower velocities.

The detailed facies classification versus P-wave velocity is shown in the violin plot in Figure 17. Horizontal P-wave velocity (VPH) for fine grainstone samples is between 3800 and 5230 m/s (median 4112 m/s), while the petrographic analysis shows low porosity of about 7%.

Bioturbated grainstone shows a wide variation in VPH between about 2400 and 4500 m/s.

Similarly, cross-bedded grainstone facies show a wide range of VPH from 2050 to 4900 m/s.

These grainstone facies are divided into flat and angular cross-bedded (CB) ooidal grainstone with varying porosity and cement content. The violin plot shows higher velocities for angular CB grainstones (median value of 4318 m/s) compared to velocities of flat CB facies (median value of 3613 m/s). Conversely, vertical P-wave velocity is higher for flat cross-bedded grainstones. This highlights the impact of sedimentary facies on rock properties in which the angular cross-bedded grainstones favour the horizontal propagation of waves.

Rudstone facies show VPH ranging between 2750 and 4700 m/s (median value of 3887 m/s) and porosity values between 9 and 16%. This velocity variation can be associated with different pore types. At a given porosity, velocity values measured for rocks with macropores (e.g., channels) are lower than velocities measured for rocks with microporosity [START_REF] Brigaud | Acoustic Properties of Ancient Shallow-Marine Carbonates. Effects of Depositional Environments and Diagenetic Processes (Middle Jurassic, Paris Basin, France)[END_REF]).

Finally, P-wave velocity measured for stylolites show median of about 4540 m/s while the vertical values are significantly lower with median value of about 2390 m/s.

Diagenetic control on velocity

Valanges section

Acoustic properties are strongly controlled by bulk density where velocities increase with increasing density and decreasing porosity [START_REF] Regnet | Influence of microporosity distribution on the mechanical behavior of oolithic carbonate rocks[END_REF]. The studied carbonates in Thin section analysis shows cementation of primary porosity and evidence of late compaction that results in sutured grain fabric. This emphasizes the role of early cementation in controlling the primary porosity. Combined with later compaction, cementation can significantly reduce the porosity and result in increased velocity values [START_REF] Brigaud | Acoustic Properties of Ancient Shallow-Marine Carbonates. Effects of Depositional Environments and Diagenetic Processes (Middle Jurassic, Paris Basin, France)[END_REF][START_REF] Brigaud | Characterization and origin of permeability-porosity heterogeneity in shallow-marine carbonates: from core scale to 3D reservoir dimension (Middle Jurassic, Paris Basin, France)[END_REF]).

The second sub-facies (flat CB grainstone) shows higher percentage of intragranular porosity (> 10%), as well as vug and channel porosity. VSH values are centred around 1800 m/s while VPH are centred between 3700 and 3800 m/s. Vuggy pores present great variations in size and shape which can result in blocking the propagation of waves and lower the velocity values [START_REF] Soete | Acoustic properties in travertines and their relation to porosity and pore types[END_REF]. The rudstone facies (M3, M4) is characterized by moderate intragranular porosity (about 11%) and less frequent vug porosity. VPH shows an average value of 3800 m/s, while VSH is 1800 m/s.

Finally, the hardground surfaces, on top of the angular cross-bedded grainstone facies and below the rudstone facies, show VPH with median value 3734 m/s. The lower velocity values can result from higher porosities associated with perforations at hard ground surfaces [START_REF] Purser | Dedolomite porosity and reservoir properties of middle Jurassic carbonates in the Paris Basin, France[END_REF].

Massangis section

The peloidal packstone facies (F1c) show VPH between 3400 and 5050 m/s, and porosity values of 15 to 20 %. The microfacies analysis shows dominating intergranular porosity on the lower part of the section (M6), whereas the upper units of the log show more intense dissolution phases (M7, M8). Consequently, vuggy porosity contributes to the total porosity and results in lower velocity values [START_REF] Dunham | The chronostratigraphic significance of seismic reflections along the Bahamas Transect[END_REF].

Finally, some samples show dolomite content and evidence of dolomite cement dissolution.

This may have contributed to secondary porosity by creating rhombic (mouldic) pores (Lønøy 2006; [START_REF] Makhloufi | Dolomitization of the upper Jurassic carbonate rocks in the Geneva Basin, Switzerland and France[END_REF]). The dedolomitization process preferentially affects sedimentary infills in perforations near hardground or bioturbation surfaces [START_REF] Purser | Dedolomite porosity and reservoir properties of middle Jurassic carbonates in the Paris Basin, France[END_REF][START_REF] Loreau | Géométrie et couleur des couches dans l'oolithe blanche de Massangis (Yonne)[END_REF][START_REF] Thomas | Contribution of drone photogrammetry to 3D outcrop modeling of facies, porosity, and permeability heterogeneities in carbonate reservoirs (Paris Basin, Middle Jurassic)[END_REF].

Synthetic seismic

Two main reflectors R1 and R2 are identified on the synthetic seismic between 0.5 and 1 m depth. The reflectors are characterized by lateral continuity from 2.5 to 12 m width. Figure 18 presents the high-resolution facies compared to the impedance values and synthetic seismic trace in depth. The seismic reflector R1 is between 1 and 1.5 m depth, at the top of the angular cross-bedded grainstone unit representing a hardground. It is a positive reflector (red kick)

representing an increasing impedance with depth from a low velocity hardground surface and rudstone unit, to a higher velocity cross-bedded grainstone unit.

The reflector R2 is a bright reflector located at 0.5 m depth at the top of the rudstone unit. This unit is overlain by about 0.8 m unit of flat cross-bedded grainstone at the top of the outcrop.

The red kick implies an increasing impedance with depth from the grainstone to the rudstone unit. The flat CB grainstone unit have a median velocity lower than that of rudstone unit (3613 m/s and 3887 m/s respectively) and is characterized by less cementation and more intragranular and channel porosity. The variation in petrophysical properties is at the origin of generating the reflector R2.

In summary, the generation of the two reflectors (R1 and R2) is related to the vertical variation in facies and their petrophysical properties. Such variations are strongly enhanced by diagenetic processes in which cementation and dissolution phases can impact the microstructures and petrophysical properties of rocks. In particular, the abrupt interruption of sedimentation leading to the development of hard ground and the subsequent diagenetic processes result in important impedance contrast.

Finally, a chaotic seismic facies is identified in the northern part of the section between 0.3 and 1.5 m depth. The sedimentologic description of this zone shows a variation of facies between grainstone (bioturbated, angular CB, and flat CB) and a zone of stylolites and karst. The rapid variation in facies, and thus, in petrophysical properties, implies a rapid succession of beds with high acoustic impedance contrast. Consequently, the seismic signal can be obliterated and result in chaotic seismic facies. Another explanation for this facies can be the presence of karst units.

The karst features have been demonstrated to exhibit lower acoustic impedance than the surrounding rocks resulting in a low-amplitude chaotic seismic facies (Sayago et al. 2012;Hendry et al. 2021;Embry et al. 2021). Mouldic pores are dominant in Massangis fm as a result of dissolution phases. The rhombic pores within packstone facies of FA1 indicate that dolomite cement was preferentially dissolved while the calcite grains were preserved [START_REF] Purser | Dedolomite porosity and reservoir properties of middle Jurassic carbonates in the Paris Basin, France[END_REF]. Consequently, these facies show macroporosity volumes up to 20% which can exert major control on the reservoir heterogeneity.

Reservoirs dominated by mouldic porosity volumes are often associated with good permeability [START_REF] Purser | Dedolomite porosity and reservoir properties of middle Jurassic carbonates in the Paris Basin, France[END_REF][START_REF] Rameil | Early diagenetic dolomitization and dedolomitization of Late Jurassic and earliest Cretaceous platform carbonates: a case study from the Jura Mountains (NW Switzerland, E France)[END_REF][START_REF] Makhloufi | Dolomitization of the upper Jurassic carbonate rocks in the Geneva Basin, Switzerland and France[END_REF][START_REF] Thomas | Contribution of drone photogrammetry to 3D outcrop modeling of facies, porosity, and permeability heterogeneities in carbonate reservoirs (Paris Basin, Middle Jurassic)[END_REF].

In this study, the combined acoustic and sedimentologic characterization of the outcrop highlights the applicability of using synthetic seismic to investigate reservoir properties. The identified seismic reflectors (R1 and R2) are the result of the sedimentologic and diagenetic control of facies on the petrophysical properties of rocks. For instance, R1 reflects angular cross-bedded unit with low porosity values that has poor reservoir quality. While R2 represents the impact of hardground surfaces that result in local increase in impedance. Together, the reflectors represent a high velocity zone with reduced porosity, and these structures can constitute barriers to flow and result in poor reservoir quality.

Applying this approach on larger scales can aid in identifying the seismic signal of different rock units. The results can then be extrapolated to similar outcrops and contribute to the petrophysical knowledge of Tidal to subtidal (FA2) and clinoforms (FA1) geobodies of Mid-Late Jurassic carbonates in the Paris Basin which represent an interesting topic to modern studies.

Conclusion

In this study we explored the sedimentological and acoustic characteristics of Mid-Late Jurassic Chapter 5: Petrographic analysis of samples from

Lebanon study case 5. Petrographic analysis

Introduction

The analysis of rocks from Kfarhelda outcrop is completed on two scales: macroscopic and microscopic. To carry out the microscopic analysis, eleven thin sections are prepared. The samples are collected from the outcrop and cut into cubes depending on their dimensions. The samples are then cut and prepared into thin sections with 30 μm thickness and inspected using optical microscope under polarized light.

The thin sections are analysed in terms of facies (texture, fabric, mineralogy, grain type, pore type) and diagenetic processes (cementation, dissolution) based on [START_REF] Dunham | The chronostratigraphic significance of seismic reflections along the Bahamas Transect[END_REF] and Choquette and Pray (1970) classifications (Figs. 19, 20). All sections are stained with alizarin red-S to differentiate carbonate minerals (calcite is stained) and impregnated with blue epoxy to identify pore space [START_REF] Dickson | Carbonate identification and genesis as revealed by staining[END_REF]. Dolomite textures are classified based on [START_REF] Sibley | Classification of dolomite rock texture[END_REF] and [START_REF] Folk | Spectral subdivision of limestone types[END_REF].

Figure 19. Schematic representation of [START_REF] Dunham | The chronostratigraphic significance of seismic reflections along the Bahamas Transect[END_REF] depositional classification of carbonates (modified after [START_REF] Dunham | The chronostratigraphic significance of seismic reflections along the Bahamas Transect[END_REF][START_REF] Embry | A Late Devonian reeftract on Northeastern Banks Island, NWT[END_REF][START_REF] Loucks | Introduction to Carbonate Environments, Facies, and Facies Tracts[END_REF].

In Chapter 6, sections 6.4.1 and 6.5.1, four facies associations are identified for the studied Based on the petrographic analysis and microfacies analysis described through field observations in Chapter 5, a paragenetic sequence can be identified for the defined microstructures (Fig. 22). It is important to note that the proposed paragenetic sequence is based on the petrographic analysis of few samples (11 samples) collected from the 400-m thick sedimentary section. It is therefore considered a simplified paragenetic sequence.

In the previously described thin sections, most of the facies associations are affected by partial or total dolomitization. The prevailing dolomitization processes are related to early dolomitization in supratidal environment, and later dolomitization processes occurring during burial. In general, fine crystalline dolomites are predominant in mudstone and wackestone microfacies at the base of the log, whereas medium to coarse crystalline dolomites are more common in grain-supported facies [START_REF] Omer | High Resolution Cathodoluminescence spectroscopy of carbonate cementation in Khurmala Formation (Paleocene-L. Eocene) from Iraqi Kurdistan Region, Northern Iraq[END_REF], mostly dominating the upper part of the log. In all cases, the different dolomitization processes prevailing through this section enhances porosity through dissolution (intercrystalline and vuggy porosity) with respect to the porosity of the original limestone facies (Nader and Swennen 2004).

Dissolution phases occur at two different stages: dissolution of grains or crystals during shallow burial of the sedimentary strata, and later dissolution of cement following the uplift of the strata.

Rock fracturing can contribute to the circulation of meteoric water within the rocks in which calcite cement is preferentially dissolved (Nader and Swennen 2004).

Additionally, in the lower part of the described sedimentary log (Fig. 30), compaction stylolites, i.e., bed parallel stylolites are common. This type of stylolites can be associated with overburden pressure resulting from lateral burial (Nader and Swennen 2004). Finally, deep burial conditions enhance calcitization processes, and favours the development of nonplanar and fabric destructive dolomite textures. This can be related to the burial history of the Cenomanian -Turonian carbonate platform by the end of the Turonian (Dubertret 1975;Noujaim 1977).

Figure 22. The sequence of diagenetic stages of the Cenomanian -Turonian carbonates exposed in Kfarhelda north Lebanon (the blue dash represents FA1, purple is for FA2, green is for FA3, red is for FA4, and the black coloured dash represents all facies associations).

Depositional environments

Based on the microstructure's description, petrographic analysis, and the identification of the vertical and lateral variation of facies (explained in chapter 6), a simple depositional model is proposed for the studied Kfarhelda outcrop, divided into four depositional environments representing ramp depositional settings (Fig. 23).

First, a supratidal/inner ramp depositional environment is proposed (FA1, Fig. 23). It is presented by dolomite textures overlain by laminated mud-dominated facies. During the Late Cenomanian, shallowing marine conditions prevailed and favoured the supratidal depositional environment. This was followed by maximum transgression conditions (Sharland et al. 2001) that resulted in the deposition of marly limestone (Fig. 24a) and mud supported facies with cherts (Fig. 24b) as well as local channel facies (Fig. 24c). The depositional conditions changes during the Early Turonian into shallower marine setting characterized by the deposition of wackestone to packstone facies with some rudists (FA2).

During the Mid Turonian, major regression affected north Lebanon resulting in shallower marine conditions (FA3) and the deposition of rudist-rich rudstones (Fig. 25a) and bioclastic grain-supported facies (Fig. 25b, Hawie et al. 2013a). Shallowing conditions continuous leading to the deposition of dolostones in supratidal depositional setting (Fig. 25c). By the end of the Turonian, laminated mudstone facies dominate indicating the return from supratidal to shallowmarine settings (FA4, Fig. 26) (Noujaim 1977). Throughout this article, the workflow described in the methodology section (Chapter 3) is applied on the Kfarhelda outcrop, and a correlation between the outcrop and seismic data is accomplished.

Additional information

This section presents additional information related to the methodology:

- Seismic reflection is an essential method used to provide insights into sedimentary basin's architecture and tectonosedimentary evolution [START_REF] Eberli | Seismic imaging of carbonate reservoirs and systems[END_REF]. Seismic reflections result from the contrasts in acoustic impedance (AI), a product of sonic velocity and density (Sheriff, 1977). Even with little variation in composition and mineralogy, carbonates show a wide range of velocity and AI [START_REF] Anselmetti | Sonic velocity in carbonates -A combined product of depositional lithology and diagenetic alterations[END_REF]. Such changes are strongly related to the variation of porosity and pore structure, which is influenced by primary microstructures acquired during sediment deposition, as well as secondary microstructures modified by diagenetic processes (Adelinet et al., 2019;Bailly, Adelinet, et al., 2019;Fournier & Borgomano, 2007).

The interpretation of seismic data is based on stratigraphic principles correlating genetically related sedimentary strata at depth (Vail et al., 1977). The reflectors are presumed to follow depositional surfaces and erosional unconformities (Mitchum, 1977). Seismic facies analysis was introduced as a useful tool to better interpret carbonate rocks on seismic data and provide a more complete geologic insight within a sedimentary basin (Berg, 1982;Fontaine et al., 1987;Mitchum, 1977). However, carbonates are greatly impacted by diagenetic processes that lead to spatial changes in porosity and pore structures, thus, altering the primary petrophysical properties of rocks (Teillet et al., 2020;Wagner, 1997). As a consequence, the seismic image may be disrupted, and the sedimentologic and stratigraphic interpretations of seismic data become more challenging [START_REF] Anselmetti | Sonic velocity in carbonates -A combined product of depositional lithology and diagenetic alterations[END_REF][START_REF] Eberli | Factors controlling elastic properties in carbonate sediments and rocks[END_REF]Fournier & Borgomano, 2007). To understand the geological origin of seismic reflectors, the integration of sedimentologic and stratigraphic description with a physical characterization of rocks is essential.

Synthetic seismic modelling was presented as a primary tool to correlate seismic data with borehole data for better control of subsurface mapping (Embry et al., 2021;Rekoske & Hicks, 1992;Teillet et al., 2020). Two-dimensional synthetic seismic modelling is used to generate seismic sections for large-scale outcrop analogues and compare them to the subsurface seismic data. This method is based on ultrasonic measurements and petrophysical characterization of samples collected from outcrops (Jafarian et al., 2018;Kleipool et al., 2017;[START_REF] Zeller | Sequence architecture and heterogeneities of a field-Scale Vaca Muerta analog (Neuqu´en Basin, Argentina) -from outcrop to synthetic seismic[END_REF].

Nevertheless, a P-wave velocity measured at plug scale is not accurately representative of heterogeneities at the outcrop scale. For instance, Matonti et al. (2015) discussed the scale dependency of P-wave velocity in which in situ velocities are generally lower than plug-scale velocities because of large heterogeneities (diagenesis, fractures, stylolites). Bailly, Fortin et al.

(2019) used a multiscale representative elementary volume concept to explain P-wave velocity variation due to upscaling. Although matrix porosity controls the ultrasonic P-wave velocity at the plug scale, crack and fracture porosity appears to impact significantly the sonic and seismic velocities, respectively. Therefore, with upscaling, P-wave velocity values vary in response to different geological heterogeneities (Boadu & Long, 1996;Lubbe & Worthington, 2006;Matonti et al., 2015).

In this study, we apply an integrated workflow based on the geological characterization of a Cenomanian-Turonian carbonate platform (onshore northern Lebanon) and its physical properties (acoustic, density, porosity) to generate a 1D synthetic seismogram. A thorough sedimentological description is completed for the studied outcrop located in Kfarhelda, north Lebanon (Figure 27a). Then, P-wave velocity is acquired directly at the outcrop, whereas

Geological background

The Eastern Mediterranean is a collage of fragmented tectonic terranes situated among the African, Arabian and Anatolian plates (Figure 27a). The formation of the Eastern Mediterranean was induced by three main rifting phases during the Late Permian, Late Triassic and Early Jurassic. In the Late Jurassic, the rifting activity ceased, and the initiation of passive margin was succeeded by the deposition of marine carbonates and deep-water siliciclastics along the westward-deepening slope (Dercourt et al., 1986;[START_REF] Gardosh | Tethyan rifting in the Levant Region and its role in Early Mesozoic crustal evolution[END_REF]Garfunkel, 1998;Hawie et al., 2015;[START_REF] Robertson | Tectonic significance of the Eratosthenes Seamount: a continental fragment in the process of collision with a subduction zone in the eastern Mediterranean Ocean Drilling Program Leg 160[END_REF][START_REF] Wood | Rethinking post-Hercynian basin development: Eastern Mediterranean Region[END_REF].

Onshore Lebanon, the Jurassic succession represents the core of Mount Lebanon deposited during prevailing shallow-marine carbonate platform settings. During the Late Jurassic, a global relative sea level fall and the following continental volcanism led to the deposition of Bhannes formation (Figure 27b; [START_REF] Abdel-Rahman | Mesozoic volcanism in the Middle East: geochemical, isotopic and petro-genetic evolution of extension-related alkali basalts from central Lebanon[END_REF]Walley, 1997). The uppermost Kimmeridgian-Tithonian is characterized by a shallow-marine platform representing Bikfaya and Salima formations, deposited in warm conditions, following a marine transgression (Walley, 1997).

The Bikfaya formation is composed of massive fossiliferous carbonates with chert nodules (Nader et al., 2007), whereas the Salima formation represents a massive-to-thinly bedded oolitic limestones alternating with brown marls (Dubertret, 1975;Walley, 1997). The Late Jurassic-Early Cretaceous period was characterized by uplift and local emergence in northern Lebanon.

As a result, the Jurassic-Cretaceous boundary is marked by an erosional unconformity in which the Berriasian rock units are absent from the Levant margin [START_REF] Abdel-Rahman | Mesozoic volcanism in the Middle East: geochemical, isotopic and petro-genetic evolution of extension-related alkali basalts from central Lebanon[END_REF]Dubertret, 1975;Nader et al., 2007). Chouf formation overlies this unconformity representing fluviodeltaic siliciclastic sediments (Walley, 1997). Overlying the Chouf formation is a transition unit of fossiliferous limestones, marls and sandstones known as Abeih formation (Late Barremian) (Dubertret, 1975).

Sea-level rises during the Aptian resulted in the deposition of massive (reefal) limestones known as the Mdairej formation (Walley, 1997). The overlying Hammana formation is composed of limestones, marls and terrigenous sediments deposited in near-shore conditions during the Late Aptian to Albian (Noujaim, 1977). Maximum transgression prevailed in northern Lebanon from the Cenomanian and resulted in the deposition of Sannine formation which shows east-west facies change (Nader et al., 2016). Shallow-marine medium-to-thickbedded limestones are observed to the east, whereas thinly bedded, chalky and cherty sediments are observed westward in deeper-marine conditions (Nader et al., 2006;Walley, 1997). Finally, shallowing-marine conditions prevailed during the Turonian leading to the deposition of Maameltain formation. It is composed of massive-to-thinly bedded limestone alternating with marls and representing a shallowing-upward trend, in which outer ramp facies are overlain by shallower marine facies, followed by a sharp return to deeper-marine conditions (Dubertret, 1975;Hawie, Deschamps, et al., 2013;Noujaim, 1977).

Methodology

The studied Kfarhelda outcrop represents a Cenomanian-Turonian succession of carbonates (Hawie, Deschamps, et al., 2013). The age of this sedimentary infill is well constrained by sedimentologic and biostratigraphic studies (Hawie, Deschamps, et al., 2013;Nader, 2000). Our study focuses on the upper part of Sannine formation composed of medium-to-thick bedded limestone, and the overlying Maameltain formation characterized by rudist-rich limestone.

Field work

Sedimentological investigation

A thorough sedimentary description was completed for the 400-m-thick Kfarhelda sedimentary section including lithology and texture description of each bed. Based on field observations and facies description, we defined facies associations (FAs) and built a sedimentary log.

Acoustic properties

P-wave velocity was acquired directly on the outcrop using Pundit PL-200 device, under atmospheric pressure and in dry conditions. The waves propagate through the rock between the transmitter and the receiver were the total travel time is recorded, and the velocity is obtained by dividing the total travel time to the spacing between the sensors, with less than 5% travel time error (Bailly, Fortin, et al., 2019). The velocities were obtained using 40 kHz P-wave sensors. The spacing (L) between the emitter and receiver is maintained constant at around 40 cm. This ensures that the number of cumulative wavelengths is enough to have a representative velocity data set. The measurements are acquired horizontally, parallel to the bedding, with a vertical spacing of 1 m. The inclination of the beds allowed us to measure the acoustic properties of 419-m-thick sedimentary series.

Laboratory measurements

A total of 44 samples were collected from the outcrop, relatively one sample every 10 m along a vertical section. Depending on their size, the samples were cut into cubes to acquire physical properties. The density and porosity values of rock samples were calculated using triple-weight method by measuring sample mass in dry condition, fluid-saturated condition and fluidsaturated submerged in the saturating fluid. First, the samples are dried in oven at 60°C for 24 h to measure the dry mass (mdry). Then, the samples are placed in a desiccator connected to a pump to ensure vacuum conditions for a minimum of 8 h. The desiccator is connected at the same time to an Erlenmeyer filled with de-mineralized water. The water is routed to the desiccator, and the samples are soaked for minimum 12 h. Finally, the submerged mass (msub)

and saturated mass (msat) are measured, and the porosity, bulk density and mineral density are calculated based on the following equations:

Porosity = 𝑀 𝑠𝑎𝑡 -𝑀 𝑑𝑟𝑦 𝑀 𝑠𝑎𝑡 -𝑀 𝑠𝑢𝑏 × 100 (1)
Bulk density (ρ𝑏𝑢𝑙𝑘) =

𝑀 𝑑𝑟𝑦 𝑀 𝑠𝑎𝑡 -𝑀 𝑠𝑢𝑏 (2)
Mineral density (ρ𝑚𝑖𝑛) = 𝑀 𝑑𝑟𝑦 𝑀 𝑑𝑟𝑦 -𝑀 𝑠𝑢𝑏

(3)

Synthetic seismic modelling

Based on the outcrop and laboratory data set, a 1D synthetic seismogram is generated. The seismic response is primarily controlled by acoustic impedance (AI) representing the product of P-wave velocity (Vp) and bulk density (ρbulk). Two approaches were applied to calculate AI values while accounting to the resolution difference between velocity and density data. In the first approach, assumptions were made on density values to create grid dimensions comparable to the velocity grid. These assumptions were based on density values measured from the samples, and the sedimentological observations on the outcrop. In the second approach, AI values were calculated based on average velocity values comparable to the density grid dimensions. The two seismograms show good fit as a low frequency Ricker wavelet is used in generating the seismic trace.

The computed AI is used to calculate the reflection coefficient (RC) (Equation 4), which is then convoluted to seismic trace at zero-phase Ricker wavelet (Jafarian et al., 2018;[START_REF] Stafleu | Seismic models of a prograding carbonate platform: Vercors, south-east France[END_REF].

RC = 𝐴𝐼 2 -𝐴𝐼 1 𝐴𝐼 2 + 𝐴𝐼 1 (4)
The Ricker wavelet is the second derivative of the Gaussian function, defined by one central frequency. It is widely used in synthetic seismic computation as its asymmetrical amplitude spectrum is similar to the attenuation feature of seismic wave propagation (Wang, 2015). In this study, a zero-phase Ricker wavelet was used to generate the seismogram as the 2D onshore seismic profile was processed using zero-phase conversion.

For P-wave velocity between 2000 and 6000 m/s, using a central frequency 25 Hz implies a resolution between 20 and 60 m (wavelength/4). This allows the comparison between the outcrop geological data and the onshore 2D seismic profile.

Seismic interpretation

The 2D seismic profile SLEB-2D-01-13 with EW orientation (Figure 27a) was acquired in 2013 and processed by Spectrum Geo Ltd. following Kirchhoff Pre-stack Time Migration (PSTM).

PSTM was run with velocities smoothed over 2 km, 1 km and 500 m intervals when appropriate for the final pass of velocity analysis using CDP gathers, constant velocity stacks and contoured semblance displays. The line has a 44 km linear distance from Batroun coastal city to Ainata village passing through difficult irregular terrains. The interpretation of the profile was done at the Lebanese Petroleum Administration using Petrel software. Interpretation and time-depth conversion were completed after the work of Nader et al. (2016). The depth of time-picked reflectors was calculated using the proposed velocity model based on Dix equation [START_REF] Dix | Seismic velocities from surface measurements[END_REF] see Nader et al. (2016) for velocity model). Additionally, detailed sedimentological interpretation of Kfarhelda outcrop was used to identify local seismic facies of Cenomanian-Turonian age.

Seismic attributes represent the internal properties of a seismic signal obtained from seismic data (e.g., amplitude and frequency) [START_REF] Nanda | Seismic data interpretation and evaluation for hydrocarbon exploration and production[END_REF]. It is considered a helpful tool for distinguishing lateral lithological changes [START_REF] Chopra | Seismic attributes for prospect identification and reservoir characterisation[END_REF]. The seismic attributes used in this study are the relative AI and the root mean square (RMS) amplitude. Relative AI attribute represents contrast in physical properties or apparent AI. It is used for lithology discrimination and variations in thickness. Additionally, it can indicate unconformity surfaces, discontinuities or sequences boundaries [START_REF] Oyeyemi | Seismic attributes analysis for reservoir characterisation; offshore Niger delta[END_REF]. RMS attribute is also related to AI and is similar to reflection strength. Higher AI values imply higher RMS amplitude. It is also used to detect unconformities, lithology changes and channels variations [START_REF] Emujakporue | Identification of seismic attributes for hydrocarbon prospecting of Akos field, Niger Delta, Nigeria[END_REF].

6.4. Results

Sedimentary log description

Based on field and samples observations, 13 facies were identified for the entire stratigraphic interval, defining 4 facies associations (FAs): supratidal/inner ramp (FA1), outer ramp (FA2), shallow-marine platform (FA3) and mid-ramp (FA4) (Figure 28). The lower 5 m of the section present fine crystalline dolomites dominantly laminated with calcite pseudo-morphs. These are overlain by a massive unit of bioclastic wackestone (Figure 29a), intercalated with thin layers of mudstone (1-3 m) up to 40 m. It is characterized by frequent calcite cemented vugs, weathering and fracturing, as well as porosity (micro-and fenestral porosity). Between 41 and 80 m, the texture becomes dominantly mudstone with cherts (Figure 29b). This mudstone unit is characterized by frequent stylolites (Figure 29c), bioturbations, fracturing and weathering.

A bioclastic-rich packstone to wackestone unit dominates the section between 82 and 129 m with mud intercalations, overlain by 6 m of bioclastic floatstone (131-137 m) (Figure 29d).

Then, a unit of laminated mudstone with cherts is observed from 139 m with intervals of packstone (153-160 m), followed by another unit of mudstone up to 178 m. Between 179 and 213 m, the texture changes into massive bioclastic packstone to wackestone, with mudstone interbeds. It is followed by a unit of mudstone with internal erosion, and reworking breccias with slumping structures between 214 and 218 m (Figure 29e).

Between 219 and 267 m, we observed a unit of bioclastic-rich rudstone to grainstone with abundant rudists and gastropods (Figure 29f). This unit is also interbedded with bioclastic mudstone to wackestone layers (1-5 m). The outcrop was not describable from 285 to 294 m.

At 300 m, we identified a layer of algal boundstone (Figure 29g), overlaid by a thick unit of dolomites (303-329 m) (Figure 29h). A thick unit of massive bioclastic wackestone to packstone is observed between 330 and 346 m, overlain by alternating units of dolomites and mudstone up to 382 m. It is followed by a massive, brecciated rock unit (2-5 m) at 383 m, alternating with layers of thinly bedded bioclastic rudstone to packstone (1-4 m) (Figure 29i) up to the top of the log at 419 m. These observations are used to build a sedimentary log of the outcrop representing Cenomanian-Turonian carbonate rocks (Figure 30). 6.5. Discussion

Sedimentary facies associations

The completed fieldwork provided a sedimentary log covering of the Cenomanian-Turonian outcrop studied in Kfarhelda. Four facies associations (FAs) were identified for the outcrop based on field observations and literature of regional geology and stratigraphic evolution of northern Lebanon (Beydoun, 1977;Dubertret, 1975;Hawie, Gorini, et al., 2013;Nader, 2011;Saint-Marc, 1972). The Cenomanian-Turonian carbonate platform prevailed along the Levant margin and presented important rudist accumulations along the Turonian mid-ramp configuration (Nader, 2000;Saint-Marc, 1972). The FAs attested in Kfarhelda outcrop fit well with major eustatic fluctuations during the Cenomanian-Turonian.

The FA (FA1) at the base of the outcrop refers to supratidal/inner ramp configuration.

Laminated fine crystalline dolomite (F1a) represents the supratidal depositional setting. F1b consists of massive thinly bedded mudstone to wackestone, and F1c represents a unit of thinly bedded mudstone to wackestone with cemented vugs. The main difference with F1c is the abundance of chert nodules marking deepening conditions, consistent with the maximum transgression conditions affecting the Arabian plate from the Early Cenomanian to the Early Turonian (Sharland et al., 2001). F1d consists of bioclastic-rich packstone to floatstone units with rudists, gastropods and bivalves, representing shallowing-upward channel facies (Nader et al., 2006).

Two facies are identified for the outer ramp FA (FA2): massive-to-thinly bedded bioclastic packstone to wackestone (F2a), and thinly bedded mudstone (F2b). Additionally, FA (FA3) represents shallow-marine platform consisting of bioclastic rudstone to grainstone facies with abundant rudists (F3a), and bioclastic packstone to wackestone facies (F3b). The Turonian carbonate platforms with rudist accumulations have been extensively studied on the Arabian Plate (Saint-Marc, 1972, 1974). During the Mid-Turonian, shallowing trend with major regression, enhanced by Levant marginal uplift, affected the Levant area explaining the sharp transition into the rudist-rich rudstone platforms [START_REF] Haq | Mesozoic and Cenozoic chronostratigraphy and eustatic cycles[END_REF]Hawie, Deschamps, et al., 2013). The dolomite textures with chicken wire structures (F3d) mark further shallowing and a shift into supratidal depositional setting (Nader et al., 2016).

The facies F4a (in FA4) consists of massive brecciated packstone indicating slope instability during the Mid-to-Late Turonian. The alteration of brecciated rock units could be due to the tectonic movements associated with the complex structural evolution of the Levant margin, such as the Syrian arc folding initiated from Late Turonian (Brew et al., 2001;Walley, 1998).

Rudstone to floatstone facies (F4b) marks a progressive return to shallow-marine settings, followed by deeper laminated mudstone to wackestone facies (F4c) at the top of the Turonian series (Noujaim, 1977). The Levant margin is characterized by deepening of sedimentary facies during the Late Turonian (Hawie, Deschamps, et al., 2013). Reflector R1 (Figure 32) is a high amplitude negative reflector at the base of the log resulting from upward decrease in porosity at the transition between fractured dolomite (F1a) and tight mudstone facies (F1b). R2 is a high amplitude positive reflector controlled by positive reflection coefficients (RCs), whereas R3 is a negative reflector resulting from sharp contrast in AI at the transition between mud-dominated facies F1b and F1c. Both facies represent mud-supported limestone yet with two distinctive differences: F1b includes marl intercalations causing the sharp decrease in velocity values. In contrast, F1c represents mudstone with chert nodules and abundant stylolites. Consequently, velocity values observed for F1b and F1c show significant scattering (Figure 31b), outlining an impact of the outcropping diagenetic features. This implies that these high amplitude reflectors observed at the base of the log correspond to vertical facies variation and contrasts in physical properties enhanced by diagenetic features.

High-to-moderate amplitude reflectors form at the transition between two facies. For instance, a bioclastic packstone unit ( F1d) is observed at 80 m representing a channel facies with coarsening upward trend. This unit is associated with lower velocity values and moderate porosity (∼12%). The contrast with the underlying less porous mudstone units (F1c) resulted in the generation of the positive reflector R4. Conversely, R5 is a negative reflector representing a trend of decreasing upward porosity. Observations at the outcrop show an interesting contrast at around 150 m. This limit marks the end of bioturbation dominating the previous unit, and a fining upward trend.

Between 190 and 230 m, the log is dominated by bioclastic packstone (F2a) and rudstone to grainstone facies (F3a). This section is generally characterized by lower velocity values and increasing porosity (11%). Consequently, the sharp contrast with the underlying mudstone unit generates the positive reflector R6. This reflector represents an important stratigraphic limit, at the transition between FA2 and FA3, marking the Mid-Turonian shallowing trend and the deposition of rudist-rich rudstone platforms.

A unit of less porous bioclastic packstone (F3b) overlies the rudstone platform at around 233 m, generating the negative reflector R7. Conversely, the reflector R8 does not appear to represent a boundary or facies transition, but rather a vertical variation in porosity and AI pointing to a diagenetic contrast. Finally, R12 is a positive reflector marking the transition between FA3 and FA4, associated with an increasing porosity trend for the brecciated packstone unit (14%). This clearly demonstrates that the vertical variation in acoustic properties is related to facies variation in which the main reflectors remain in accordance with the depositional timeline and initial petrophysical properties.

The very low amplitude reflectors (R9, R10 and R11) at the upper part of the log are associated with a thick unit of dolomites (∼30 m) and an overlying highly karstified section of alternating dolomite and mudstone/wackestone textures (mineral density ∼2.8 g/m3). The velocity values vary within these beds, whereas the porosity remains relatively low (4%-7%). This can be explained by the homogenization effect of diagenesis that masks the contrasts related to the vertical variation of facies [START_REF] Bailly | Controlling factors of acoustic properties in continental carbonates: implications for high-resolution seismic imaging[END_REF]. Finally, sections that are characterized by vast variations of physical properties result in rapid succession of beds with high AI contrasts.

Consequently, the seismic signal is obliterated, and no reflectors are observed between 120 and 150 m.

Seismic interpretation and seismic facies analysis

Interpretation

A section of the onshore 2D seismic profile was interpreted to identify major seismic reflectors and assign proper lithostratigraphic attributes to the seismic facies. Figure 33a presents a satellite image showing the relative locations of the outcrop and the 2D seismic profile. Figure 33b shows the relative location of the studied Kfarhelda outcrop to the interpreted section of the 2D seismic profile.

Six reflectors were identified on the studied section of the 2D seismic profile (H1, H15, H14, H13, H10, H6) (Figure 33b). 6.5.4. Outcrop to seismic tie and seismic-stratigraphic context P-wave velocities were acquired horizontally on the outcrop at 40 kHz frequency representing a pluri-centimetre scale (40 cm). Acoustic measurements from Kfarhelda outcrop were acquired in dry conditions and under atmospheric pressure (0.1 MPa). In burial conditions, P-wave velocity is modified under the impact of confining pressure, depending on the condition of initial porosity, pore type and cracks (Anselmetti et al., 1997;[START_REF] Fournier | Elastic properties of microporous cemented grainstones[END_REF]Matonti et al., 2015). The studied Cenomanian-Turonian carbonate outcrop shows a low amount of burial.

Thus, the acoustic measurements acquired on the outcrop can be used to interpret the corresponding onshore seismic line.

The best fit between the synthetic seismic and seismic profile is presented in Figure 36. At the base of the sedimentary log, reflectors R1, R2 and R3 have the highest amplitude for synthetic traces at the vicinity of high RCs (in absolute value). Similarly, the seismic profile shows moderate amplitudes within seismic facies S1, particularly for reflectors S1b, S1c and S1d, whereas S1a shows lower amplitude (Figures 35a and36). To correlate the outcrop data with seismic data, we introduce a pseudo well W1 representing the sedimentologic log of Kfarhelda outcrop (Figure 35a). The location was estimated based on the seismic trace and GPS data of the outcrop. The well represents the studied sedimentologic log between 0 and 213 m. The well reaches the Upper Cenomanian unit of 'Sannine formation' with a total thickness of 213 m.

This unit is identified as the seismic facies S1 characterized by medium-to-thick bedded limestone and marly limestone sediments (Walley, 1998). The relative locations of W1 on the seismic line as well as the studied outcrop are shown in Figure 35a.

A succession comprised alternations of marl, marly limestone and mudstone is identified as the Marly Limestone Zone (MLZ), responsible for creating AI contrast. However, these marl intercalations have a relatively low thickness (∼8 m), at the limit of resolution of seismic data.

This results in seismic signal interference and seismic tuning due to the strong overlap of reflective signals from marl and limestone strata, making it difficult to precisely detect the limits of the marly zone using seismic data alone [START_REF] Słonka | Seismic characteristics and development of the upper Jurassic Carbonate Buildups from the Miechów Trough (Southern Poland)[END_REF].

Above the MLZ, a unit associated with inner ramp carbonate deposits is present and characterized by mudstone containing chert. Similarly, a unit of massive limestone (mudstone to wackestone) is present below MLZ and characterized by higher velocities. Consequently, the strong AI created at the limits of the MLZ results in a series of high amplitude (positive and negative) seismic reflectors.

The positive seismic reflector generated below S1d has a very low frequency and cannot be clearly interpreted. This can be related to the presence of the dolomite unit identified at the base of the well. This unit may extend deeper below the studied outcrop, resulting in a thick dolomite unit that can mask the vertical contrast in AI. Consequently, a chaotic, low amplitude, low frequency seismic image is observed (Figure 35a). In contrast, the synthetic seismic reflectors R1 and R2 show higher amplitude because the vertical variation of physical properties is better represented on the synthetic seismogram, resulting in sharp contrasts and higher resolution reflectors.

A unit of channel facies is identified above the mudstone and characterized by coarsening upward trend. This unit, dominated by bioclastic floatstone, is associated with changes in physical properties (higher porosity and lower velocity). It induces a contrast in AI and, consequently, generates a seismic reflector (S1c). It corresponds to the reflector R4 on the synthetic seismogram, a positive reflector with moderate amplitude.

Root mean square (RMS) and relative AI seismic attributes are used to distinguish channels for this section. Figure 35b, c shows that the channel facies unit identified on the sedimentologic log have a good match with the bright spots identified on the RMS seismic attribute. RMS attribute is usually used to detect bright spots of porous sand representing possible hydrocarbon reservoir [START_REF] Brown | Understanding seismic attributes[END_REF][START_REF] Mangal | Identification of shallow gas prospect from DHC and inversion studies of 2D seismic data, Kosamba oil field, South Cambay Basin, Gujarat, India[END_REF][START_REF] Mcquillin | An introduction to seismic interpretation: reflection seismic in petroleum exploration[END_REF]. Indeed, using RMS attribute to detect coarser-grained facies, such as channel facies, is an approach commonly used in the literature [START_REF] Emujakporue | Identification of seismic attributes for hydrocarbon prospecting of Akos field, Niger Delta, Nigeria[END_REF][START_REF] Ghoneimi | A new deeper channel system predicted using seismic attributes in scarab gas field, west delta deep marine concession, Egypt[END_REF][START_REF] Hossain | Application of seismic attribute analysis in fluvial seismic geomorphology[END_REF][START_REF] Oyeyemi | Seismic attributes analysis for reservoir characterisation; offshore Niger delta[END_REF].

The stratigraphic and sedimentologic descriptions show that the seismic reflector S1b can be associated with a sharp transition between inner ramp deposits and a unit of supratidal dolomites. On the contrary, no reflectors are identified for the synthetic seismogram within this section. This was previously explained as signal cancellation resulting from rapid alternations in AI.

At the top of the well, the synthetic seismic does not show a good fit with the seismic profile.

Onshore seismic reflection data are generally characterized with seismic noise near the surface of the earth. The top 10-30 m are associated with slower velocities causing the wavelength to be shorter. Consequently, the wavelength is impacted by small-scale heterogeneities (0.5-10 m) causing energy scattering and distortion of the signal [START_REF] Stork | How does the thin near surface of the earth produce 10-100 times more noise on land seismic data than on marine data?[END_REF].

In summary, the major seismic reflectors are related to vertical variations of the principal physical properties, including porosity, mineralogy and velocity. The correlation between synthetic seismogram and seismic data generated for Kfarhelda outcrop shows two units with significant seismic signatures: the MLZ (high amplitude negative reflector) and channel facies (high-to-moderate amplitude positive reflector).

This study provides a sedimentological characterization of the Cenomanian-Turonian sedimentary succession in north Lebanon. The interpretation of seismic data is often complicated by uncertainties and poor image quality. Indeed, outcrop analogues can provide a key tool for the characterization of a carbonate platform system by unravelling the geological details beneath the seismic reflection resolution (Hendry et al., 2021;[START_REF] Howell | The application of outcrop analogues in geological modelling: a review, present status and future outlook[END_REF].

The comparison between synthetic seismic models, based on observations and data from the outcrop, can provide insight into the best interpretation of the seismic data. In this study, the geological origin of seismic reflectors and the relative control of facies distribution were identified. These findings are of importance for the seismic interpretation of onshore profiles because it shows the seismic signature of the Cenomanian-Turonian stratigraphic sequence, making it an adaptable approach for similar sedimentary succession.

Indeed, carbonate platforms exhibit a high degree of heterogeneity and reservoir complexity (Hendry et al., 2021). Our work demonstrates that the main seismic reflectors observed for the studied outcrop coincide with stratigraphic boundaries. However, this study highlights the need for advanced petrographic and petrophysical investigation to understand the intensity of diagenetic processes and their impact on the evolution of rocks' physical properties.

Conclusion

In the present study, we discussed the sedimentological and geophysical characteristics of a Cenomanian-Turonian shallow-marine carbonate platform located in Kfarhelda, northern

Lebanon. An extensive sedimentological investigation over the outcrop allowed the identification of four facies associations (FAs): supratidal/inner ramp (FA1), outer ramp (FA2), shallow-marine platform (FA3) and mid-ramp (FA4). Acoustic properties were acquired directly on the outcrop using Pundit PL ( 200 Finally, applying this approach on similar outcrops will aid in investigating the complete Cenomanian-Turonian carbonate platform, for better petrophysical and acoustic characterization of facies and constraining of the carbonate platform properties on seismic data.

Discussion

General discussion

In this thesis project, we proposed an innovative integrated workflow to study shallow marine carbonate platforms. The workflow is based on field sedimentological description and acoustic measurements combined with petrographic and petrophysical analysis to identify the major parameters (depositional and diagenetic) causing the heterogeneity of carbonate rocks. Then, these data are used to generate synthetic seismic data to understand the geological meaning of the seismic reflectors.

Since the studied outcrops consists of carbonate rocks, no major mineralogical changes are observed. Therefore, the main factors affecting the generation of seismic reflectors are the changes in depositional facies and the variation in physical properties of beds. These variations occur at a scale below the seismic resolution. Investigating outcrop data and employing synthetic seismic methods to correlate outcrop with seismic data appears to fill the resolution gap.

In the Massangis test case, this approach proved to be beneficial for identifying the impact of facies variation (texture, microstructures) and diagenetic features on the evolution of physical properties and hence, the generation of seismic reflectors. In particular, the study highlights the role of cross-bedded grainstone facies in the variation of acoustic properties, as well as the importance of hard ground surfaces in enhancing the diagenetic processes and creating strong impedance contrast. However, the synthetic seismic method is employed using very high wavelet frequency (5 kHz) implying a centimetric resolution. Although this approach allows to identify the impact of micro and macro structures on acoustic properties, evaluating the real value of the proposed approach relies on its application on large scale outcrops.

Applying this workflow on Kfarhelda outcrop allowed us to generate synthetic seismic trace for a large-scale outcrop. Seismograms generated using low-frequency wavelet do not resolve detailed depositional geometries, however, the small-scale variations falling below seismic resolution (centimetric to metric scale) contribute to the amplitude strength of the generated seismic reflectors [START_REF] Nichols | Sedimentology and Stratigraphy[END_REF].

Contribution to the geological map

Several field visits were conducted along the 2D onshore seismic profile, from Batroun in western Lebanon near the coast, to Kfarhelda in central Lebanon (Fig. 37a). These visits focused on structural observations, documentation of outcropping rocks, and strike and dip measurements acquired along the pathway. The main objective is to map the outcropping rocks along a section of the 2D seismic line and construct an updated geological cross-section.

The cross-section follows the pathway of the seismic profile between Batroun and Kfarhelda.

It is constructed based on the geological maps of Lebanon (scale 1:50,000 - Dubertret, 1955 and1975) and the previous work of Nader et al. (2016). The cross-section extends almost eastwest from Batroun to Kfarhelda village, crossing the western Lebanon monocline (Fig. 37b).

Massive Cenomanian -Turonian carbonates outcrops to the east of Batroun city until the Abrine structure were the Albian -Cenomanian Sannine formation is exposed.

Sannine and Maameltain fm outcrops near Bijdarfil, and the Chekka formation is exposed in some places nearby. The cross-section then crosses towards Kfarhelda region in which this area is almost entirely characterized by outcropping Sannine and Maameltain fm. The Upper Turonian -Senonian transition can be observed in Kfarhelda area (Hawie et al. 2014), at the top of the sedimentologic log studied in this project. This area was previously documented to expose Quaternary deposits, however, the geological mapping carried out in this thesis project indicates Cenomanian -Turonian carbonate outcrops. The cross-section ends near Kfarhelda, nonetheless, the 2D seismic profile extends further until Ainata village in north-eastern Lebanon.

Figure 37.Geological cross-section from Batroun to Kfarhelda area, northern Lebanon crossing along the 2D onshore seismic profile pathway (scale 1:50,000 -constructed after Dubertret, 1955Dubertret, , 1975;;Hawie et al, 2014;Nader et al. 2016).

the survey, the objectives of the study, and the challenges associated with the near-surface conditions.

Another challenge arises during the interpretation of seismic data caused by karst features (dolomites). Several techniques are developed to help identifying paleokarst using seismic attributes such as frequency decomposition and colour blending (Embry et al. 2021), inverse modelling (Fournillon et al. 2021), and 3D geomorphological techniques including volume and surface attributes [START_REF] Zeng | Threedimensional seismic geomorphology and analysis of the Ordovician paleokarst drainage system in the central Tabei Uplift, northern Tarim Basin, western China[END_REF]Embry et al. 2021). The main purpose is to be able to identify karst systems and aid in locating the best target reservoirs to avoid drilling hazards [START_REF] Zeng | Threedimensional seismic geomorphology and analysis of the Ordovician paleokarst drainage system in the central Tabei Uplift, northern Tarim Basin, western China[END_REF]Burberry et al. 2016;Hendry et al. 2021).

Although large scale paleokarst systems are better identified using high quality 3D seismic dataset, smaller karst systems remain challenging in terms of evaluating their impact on reservoir properties. Properly investigating karst systems require an integration of advanced processing, well data, seismic attribute analysis, inversion modelling, or seismic-stratigraphic forward-modelling approaches (Teillet et al. 2020;[START_REF] Masiero | Syn-rift carbonate platforms in space and time: testing and refining conceptual models using stratigraphic and seismic numerical forward modelling[END_REF]Embry et al. 2021;Fournillon et al. 2021). Such an approach can be implemented to better understand karst features observed the study area, particularly from the bottom section of the log to few hundred meters deeper representing karst systems of Early Cenomanian Sannine fm (Chapter 6, section 6.3).

Implications for reservoir properties

In carbonate rocks, reservoir quality is highly impacted by facies variation and diagenetic processes. The sedimentological and petrophysical investigations conducted in this study, for the Cenomanian -Turonian carbonate platform in Kfarhelda northern Lebanon, resulted in the characterization of the depositional and diagenetic properties of these strata. These data alongside with petrographic analysis, allows us to address the potential reservoir properties of this carbonate platform.

The petrographic analysis of the Kfarhelda outcrop, described in Chapter 5, suggests that the beds are impacted mainly by processes of cementation, compaction, dissolution, and dolomitization. Dolomitization is predominant in wackestone -packstone textures especially in the upper part of the log. This process appears to enhance the porosity in dolomites compared to the original limestone facies (> 10 %). Dolomite facies are mainly characterized by rhombic porosity resulting from dedolomitization process indicating dissolution of dolomite cement and the creation of secondary pore space [START_REF] Makhloufi | Dolomitization of the upper Jurassic carbonate rocks in the Geneva Basin, Switzerland and France[END_REF][START_REF] Thomas | Contribution of drone photogrammetry to 3D outcrop modeling of facies, porosity, and permeability heterogeneities in carbonate reservoirs (Paris Basin, Middle Jurassic)[END_REF].

Dedolomitization process and the development of rhombic pores are identified mainly in FA3, particularly in F3d facies. Therefore, the higher porosities developed within dolomite units result in potentially good reservoir qualities. However, karst systems can present challenges in hydrocarbon exploration. A growing number of studies are investigating karst systems (dolomites) for development processes in which these reservoirs represent important future target reservoirs for the application of new techniques such as horizontal drilling technology [START_REF] Wilson | Introduction to Karst Systems and Paleokarst Reservoirs, In: Paleokarst Related Hydrocarbon Reservoirs[END_REF][START_REF] Sun | 3D seismic interpretation of dissolution pipes in the South China Sea: genesis by subsurface, fluid induced collapse[END_REF]Embry et al. 2021) The rudist platform exhibits interesting characteristics particularly for the rudist-rich rudstone facies and the bioclastic packstone facies. Rudstone facies are mainly controlled by two pore types: intergranular porosity and microporosity that appears to be enhanced by matrix dissolution. Petrophysical and petrographic analysis of these facies show moderate porosity (15 %). Nonetheless, overlying packstone/wackestone beds show an increased impact of cementation (cemented vugs) leading to lower porosity values.

Finally, channel facies identified in FA1, particularly in F1d facies, are characterized by higher porosity compared to mudstone -wackestone facies. This can be associated with the presence of conduits that enhances fluid flow providing increased opportunity for fluid circulation and dissolution of carbonates creating void spaces and enhancing the overall reservoir porosity.

Further petrophysical investigation can provide more information regarding the variation of permeability values, pore type, and pore geometry and the impact of these parameters on the fluid flow properties.

Conclusions

In this thesis work, we propose an integrated workflow based on sedimentologic, geophysical, petrophysical and petrographic analysis to characterize a large-scale carbonate platform located onshore Lebanon, representing Cenomanian -Turonian Sannine and Maameltain fm. Studying an onshore outcrop analogue is presented as an innovative approach to improve seismic interpretation of onshore profiles and asses the seismic characteristics of the studied rocks in the absence of well log data.

The sedimentologic investigation is completed by describing the lithology and texture of beds at each measuring point. Acoustic velocity is acquired on outcrop surface using Pundit PL-200 device at 40 kHz frequency. Few samples are then collected from the outcrop for petrophysical and petrographic analysis.

The approach is first applied to a test case study for the Mid -Late Bathonian limestones of Massangis quarry (Oolithe Blanche formation), representing an analogue of the geothermal reservoir in the Ile-de-France region. A 2D section is investigated in which 1000 acoustic values are measured to generate a 2D synthetic seismic profile using a 5 kHz Ricker wavelet. The generated synthetic seismogram allows the identification of two seismic reflectors representing areas of higher velocity and reduced porosity, in addition to a chaotic seismic facies representing a zone with important facies variation and diagenetic modification (stylolites, hardground). These results highlight the impact of facies variation and diagenetic history on the seismic properties of rocks.

In Kfarhelda, a 400 m-thick outcrop is investigated completing a sedimentary description supported with petrographic analysis of 11 samples. P-wave velocities are acquired on the outcrop with 1 m vertical spacing whereas 44 samples are collected for density and porosity measurements. The obtained data are used to generate a 1D synthetic seismic trace using a 25

Hz Ricker wavelet. The resulting reflectors are associated with karstified units (low amplitude), stratigraphic limits at the transition between facies (moderate amplitude), and limits between facies with contrasting physical properties enhanced by diagenesis (high amplitude). The This study allowed the evaluation of the developed approach presenting outcrop analogues as an essential tool to calibrate seismic data in the absence of well log data. The results of Massangis test case emphasises the impact of facies and diagenetic variations on the resulting seismic reflectors. Applying this approach on the outcrop in Kfarhelda sheds more light on the relevance of studying large-scale outcrop analogues to fill the resolution gap related to seismic data limitations and upscaling challenges.

Indeed, improving this approach implies advanced processing of the top section of the seismic profile to enhance the image quality and better represent the near-surface reflectors, as well as karistified areas. Investigating outcrop analogues located along the seismic profile will allow more accurate prediction of the depth and thickness of each bed. Finally, this study resulted in a sedimentological and seismic characterization of the Cenomanian -Turonian carbonate platform of Sannine and Maameltain formations located in Kfarhelda. Applying this approach on similar outcrops will result in better constraining the reservoir properties of this unit.

Figure 1 .Figure 2 .

 12 Figure 1. Simplified structural map of the Levant area showing major structural features and the location of the main oil/gas fields (after Le Pichon & Gaulier 1988; Hawie et al. 2013a; Nader 2014; Wood 2015). .......................................................................................................... 5 Figure 2. Simplified geological map of Lebanon showing the Locations of onshore wells, the study area, the trace of the 2D seismic profile, and the location of Lebanon in the Eastern Mediterranean (After CNRS-Lebanon; Dubertret 1955; Nader 2011; Hawie et al. 2013a). ... 12 Figure 3. The paleogeographic reconstruction of the Eastern Mediterranean during the (a) Late Permian, (b) Late Triassic, (c) Early Jurassic, (d) Early Cretaceous, and (e) Late Cretaceous, showing the main geodynamic events shaping the Eastern Mediterranean (Modified after Robertson et al. 2012). .................................................................................... 14 Figure 4. Simplified chronostratigraphic chart for onshore northern Lebanon from Jurassic to Quaternary, showing principal formations and main sedimentary facies (compiled from Walley 1997; Hawie et al. 2013b; Nader et al. 2016). ............................................................. 17

Figure 5 .Figure 9 .

 59 Figure 5. The acquisition method of acoustic measurements at outcrop scale using Pundit device. The outcrop images show the orientation of the beds and the alignment of measuring points with 1 m vertical spacing. The sketch (to the right) shows the positions of sensors connected to Pundit device, aligned horizontally on the outcrop, with L representing the spacing between sensors. .......................................................................................................... 25 Figure 6. A sketch showing the setup of the porosimetry method, (a) the setup prepared to saturate the samples, (b) the setup used to measure the submerged weight of saturated samples. .................................................................................................................................... 26 Figure 7. Schematic representation of zero-phase Ricker wavelet in time domain. ................ 28 Figure 8. (A) Simplified geological map of Paris Basin showing main Massifs and the location of Massangis quarry (modified after Brgm 1996); (B) Satellite image of Massangis quarry showing the locations of Valanges and Massangis sections (ROCAMAT 2003). ........ 36 Figure 9. Outcrop view of the 2D Valanges section and the measurement protocol. To the left, a section of the studied outcrop showing the step-by-step measurement method. To the right, an example of the sensors' setup at a measuring point............................................................. 38 Figure 10. (a) High-resolution facies distribution of Valanges fm, and (b) a simplified sedimentary log from the section showing the location of thin sections M1 to M5. ............... 41

  Figure 20. The classification of porosity in sedimentary carbonates proposed by Choquette and Pray (1970). ....................................................................................................................... 62 Figure 21. Petrographic overview of S1 to S11 samples from Kfarhelda outcrop. VP: Vuggy porosity; IP: Intergranular porosity; CC: Calcite cement; IcP: Intercrystalline porosity. ........ 67 Figure 22. The sequence of diagenetic stages of the Cenomanian -Turonian carbonates exposed in Kfarhelda north Lebanon (the blue dash represents FA1, purple is for FA2, green is for FA3, red is for FA4, and the black coloured dash represents all facies associations). ....... 70 Figure 23. A sketch illustrating the proposed ramp depositional setting for the Cenomanian -Turonian carbonate platform studied in Kfarhelda north Lebanon, representing Sannine and Maameltain formations. ........................................................................................................... 72 Figure 24. Photographs from Kfarhelda outcrop showing the inner ramp facies association (FA1): (a) marly limestone of facies F1b, (b) mudstone with chert nodules of facies F1c, and (c) bioclastic packstone of facies F1d. ..................................................................................... 73 Figure 25. Photographs from Kfarhelda outcrop showing the shallow marine platform facies association (FA3): (a) rudist-rich rudstone of facies F3a, (b) boundstone with red algae of facies F3a, and (c) medium crystalline dolomite of facies F3d. .............................................. 74 Figure 26. A photograph from Kfarhelda outcrop showing breccia (F4a) from the Mid-ramp facies association (FA4). .......................................................................................................... 75 Figure 27. (a) Simplified geological map of Lebanon showing the trace of the onshore seismic profile, and the location of the study area and available onshore wells (edited after CNRS-Lebanon; Dubertret 1955; Nader 2011). (b) Simplified chronostratigraphic chart for onshore Lebanon showing the principal formations and sedimentary facies in north Lebanon from Upper Jurassic to Upper Cretaceous. ....................................................................................... 85 Figure 28. Panoramic view of the Kfarhelda outcrop, northern Lebanon, showing the identified facies associations. Black lines inside each facies association represent the bedding. Points 0 and 419 m represent the first and the last studied points, respectively. ..................... 89 Figure 29. Cenomanian -Turonian facies of Kfarhelda outcrop: (a) bioclastic wackestone; (b) mudstone with chert nodules; (c) mudstone with stylolites; (d) bioclastic floatstone; (e) sedimentary breccia; (f) rudist-rich rudstone; (g) red algae boundstone; (h) dolomite with cemented vugs; (i) bioclastic rudstone; (j) channel facies. ...................................................... 91

  . .............................................frontier basins, representing unexplored or underexplored regions, remain a challenge for exploration efforts. The primary limitation for these basins is the lack of data availability, such as seismic data, well control, and core samples. The sparse data coverage can result in substantial uncertainties in geological interpretation and the evaluation of reservoir properties.

Figure 1 .

 1 Figure 1. Simplified structural map of the Levant area showing major structural features and the location of the main oil/gas fields (after LePichon & Gaulier 1988; Hawie et al. 2013a; Nader 2014;[START_REF] Wood | Rethinking post-Hercynian basin development: Eastern Mediterranean Region[END_REF].

Chapter 1 ,

 1 Introduction presents a general introduction and the objectives of this study. Chapter 2, Geological context, presents an overview of the sedimentologic and stratigraphic framework of Lebanon with a focus on north Lebanon region. Chapter 3, Methodology, highlights the methodology used to achieve the objectives of this study based on field investigations (sedimentology, acoustic measurements, facies analysis), laboratory petrophysical measurements, seismic modelling, and seismic interpretation. Chapter 4, Massangis test case study, this chapter consists of an introduction and geological background of the study area, methodology, results, discussion, and conclusions. Chapter 5, Petrographic analysis, a chapter explaining the results of the petrographic analysis completed on thin sections collected from Kfarhelda outcrop. Chapter 6, Lebanon study case, this chapter presents the results of the workflow conducted on an outcrop in Kfarhelda north Lebanon. An article describing the results and the discussion is presented: Abbani et al., 2023 "Seismic characterisation of Cenomanian -Turonian carbonate platform based on sedimentological and geophysical investigation of onshore analogue outcrop (northern Lebanon)", in Geophysical Prospecting. The Chapter 7, Discussion, presents a discussion around the presented results focusing on the challenges related to seismic data and the implications on reservoir properties.Finally, a conclusion, highlighting the major conclusions and proposing recommendations for

Figure 2 .

 2 Figure 2. Simplified geological map of Lebanon showing the Locations of onshore wells, the study area, the trace of the 2D seismic profile, and the location of Lebanon in the Eastern Mediterranean(After CNRS-Lebanon; Dubertret 1955; Nader 2011; Hawie et al. 2013a).

Figure 3 .

 3 Figure 3. The paleogeographic reconstruction of the Eastern Mediterranean during the (a) Late Permian, (b) Late Triassic, (c) Early Jurassic, (d) Early Cretaceous, and (e) Late Cretaceous, showing the main geodynamic events shaping the Eastern Mediterranean (Modified after Robertson et al. 2012).

Figure 4 .

 4 Figure 4. Simplified chronostratigraphic chart for onshore northern Lebanon from Jurassic to Quaternary, showing principal formations and main sedimentary facies (compiled fromWalley 1997;[START_REF] Hawie | Tectono-stratigraphic evolution of the northern Levant Basin (offshore Lebanon)[END_REF] Nader et al. 2016).

  divides the Sannine formation into the following units: (a) Hammana-Sannine Transition Unit representing mainly Late Albian massive dolomitic rocks, (b) The Lower Cenomanian Unit of the Sannine Formation consisting of bioclastic limestones, marls, thick reefal limestones and cherts, (c) The Middle Cenomanian Unit consisting of massive thinly bedded limestones with cherts in upper parts, and (d) The Upper Cenomanian Unit of the Sannine Formation consisting of thinly bedded limestones with chert intervals and fossils (Walley 1997; Nader 2014).

Figure 5 .

 5 Figure 5. The acquisition method of acoustic measurements at outcrop scale using Pundit device. The outcrop images show the orientation of the beds and the alignment of measuring points with 1 m vertical spacing. The sketch (to the right) shows the positions of sensors connected to Pundit device, aligned horizontally on the outcrop, with L representing the spacing between sensors.

Figure 6 .

 6 Figure 6. A sketch showing the setup of the porosimetry method, (a) the setup prepared to saturate the samples, (b) the setup used to measure the submerged weight of saturated samples.

Figure 7 .

 7 Figure 7. Schematic representation of zero-phase Ricker wavelet in time domain.

Figure 8 .

 8 Figure 8. (A) Simplified geological map of Paris Basin showing main Massifs and the location of Massangis quarry (modified after Brgm 1996); (B) Satellite image of Massangis quarry showing the locations of Valanges and Massangis sections (ROCAMAT 2003).

  [START_REF] Thomas | Contribution of drone photogrammetry to 3D outcrop modeling of facies, porosity, and permeability heterogeneities in carbonate reservoirs (Paris Basin, Middle Jurassic)[END_REF] and[START_REF] Vincent | Giant subaqueous carbonate dunes: a revised interpretation of large-scale oo-bioclastic clinoforms in the middle Jurassic of the Paris Basin and its implications[END_REF] provide a detailed sedimentological and diagenetic description of the Massangis quarry. The Valanges fm is defined as tidal to subtidal facies association FA2, while the Massangis fm is defined as clinoforms facies association FA1. FA2 exhibits three grain-supported facies. F2a comprises ooid grainstone with crinoids, bivalves, and brachiopods. It is characterised by perforated and bioturbated surfaces. Similarly, F2b comprises ooid grainstone with crinoids, gastropods, and herring-bone stratification but do not show perforations or bioturbations. Finally, F2c represents bioclastic grainstone to rudstone with blocky calcite cement.FA1 comprises three facies: F1b represents peloidal crinoidal packstone with bioturbations and bivalves, while F1c represents peloidal packstone with crinoids located in higher parts of the clinoforms and distinguished by the absence of bioturbation. Finally, F1d consists of ooidal and peloidal grainstone with crinoids and bivalves[START_REF] Loreau | Géométrie et couleur des couches dans l'oolithe blanche de Massangis (Yonne)[END_REF] characterized by bioclast alignments underlining the bedding. 4.3. Methodology 4.3.1. Sedimentology and petrography A detailed sedimentological description is carried out for a 2D sedimentary section (12 m wide and 2.8 m high) located on the uppermost part of the Valanges fm. Additionally, three 1 D sedimentary logs (1.6 to 3.2 m high) are studied in Massangis fm. The description is based on

Figure 9 .

 9 Figure 9. Outcrop view of the 2D Valanges section and the measurement protocol. To the left, a section of the studied outcrop showing the step-by-step measurement method. To the right, an example of the sensors' setup at a measuring point.

A

  fine time grid (10 µs sampling time) is defined to place RC at their right position in time using the measured velocities as a velocity model. Finally, RC are convoluted into seismic trace in time domain using Ricker wavelet of 5 kHz frequency. Using a high frequency wavelet results in a high-resolution seismogram representative of the outcrop scale (centimetric). The seismogram is then converted into depth using the velocity model. In the resulting 2D synthetic seismogram, the red reflectors represent positive peaks, whereas the blue reflectors represent negative peaks.

Figure 10 .

 10 Figure 10. (a) High-resolution facies distribution of Valanges fm, and (b) a simplified sedimentary log from the section showing the location of thin sections M1 to M5.

Figure 11

 11 Figure 11 shows the 1D sedimentologic logs and their relative location on the Massangis fm (FA1). The base of this section consists of peloidal crinoidal packstone facies F1b. It is overlain by peloidal packstone facies F1c.

Figure 11

 11 Figure 11. (a) Panoramic photograph of the clinoforms facies exposed in the upper part of Massangis quarry showing the locations of the studied 1D logs; (b) three simplified sedimentary logs investigated in Massangis fm showing the location of thin sections M6, M7, and M8.

Figure 12 .

 12 Figure 12. Statistical analysis of velocity data measured on Valanges 2D section: (a) A histogram showing the frequency of distribution of the measured velocities (vertical and horizontal); (b) Graph showing the normal distribution of measured velocities with the mean value and standard deviation for each category; (c) Plot showing VSH versus VPH values.

Figure 13 .

 13 Figure 13. Measured velocities from Valanges section at 40 kHz. A: Horizontal P-wave velocities, B: Vertical P-wave velocities, C: Horizontal S-wave velocities, D: Vertical S-wave velocities

Figure 15 .

 15 Figure 15. The paragenetic sequence of the Mid-Late Jurassic carbonates of Valanges fm. The diagenetic stages are composed of: Mud-enveloped grains stage; Blocky calcite cementation; Dissolution stage followed by Mosaic drusy cementation; Syntaxial overgrowth extended stage; and Compaction stage.

  Massangis quarry are affected by phases of calcite cementation. Blocky calcite cement is more frequent in Valanges section, particularly in grainstone facies. For instance, the fine grainstone facies located mostly at the base of the section (M1, F2a) is characterized by well-developed blocky calcite cement (> 15%) as well as drusy cement and syntaxial overgrowth. This facies is associated with low porosity as a result of cement reduced primary porosity. Thin section analysis shows microporosity of about 7% while the velocity is high. The majority of VPH values are greater than 4200 m/s and VSH values are greater than 2000 m/s.

Figure 17 .

 17 Figure 17. Violin plot showing the horizontal and vertical P-wave velocity measured at Valanges 2D section. Low resolution facies correspond to facies defined in Thomas et al. (2021); High resolution facies represent facies detailed in this study. The black horizontal dash represents the mean value, the white horizontal dash represents the median value.

Figure 18 .

 18 Figure 18. Figure showing comparison between high resolution facies (Valanges section), impedance (km/s.g/m 3 ), and synthetic seismic trace converted into depth using measured vertical P-wave velocities. CF: Chaotic Facies; R1 and R2: Reflectors.

  carbonates in Massangis quarry representing Valanges and Massangis formations. A detailed sedimentological investigation over a 2D section from Valanges formation allowed the realization of high-resolution facies description supported by microfacies analysis and a thorough evaluation of the main diagenetic processes. The acoustic properties are acquired directly on the outcrop using a portable device (PL 200). P-wave and S-wave velocities are obtained both horizontally and vertically at 40 kHz frequency. The measured P-wave velocities are used alongside with density data obtained from the literature to generate a 2D synthetic seismogram. The seismic trace is convoluted using 5 kHz Ricker wavelet providing a centimetric resolution.Two positive reflectors are identified parallel to each other and extending in horizontal to subhorizontal direction. These reflectors represent an area of high velocity and reduced porosity, enhanced by diagenetic processes such as cementation. A chaotic seismic facies is identified in the northern part of the section representing a zone of vast facies variation. Identifying the geological and diagenetic origin of seismic reflectors provide a helpful tool for assessing the reservoir properties such as porosity and fluid flow. The results highlight the benefits of applying this workflow at a larger scale for better understanding the acoustic and petrophysical properties of carbonate reservoirs.

  sedimentary section: FA1 -supratidal/inner ramp, FA2 -outer ramp, FA3 -shallow marine platform, and FA4 -mid ramp facies associations. This classification is based on field observations and literature related to the geology and stratigraphy of northern Lebanon(Saint- Marc 1972; Dubertret 1975; Beydoun 1977; Nader 2011;[START_REF] Hawie | Tectono-stratigraphic evolution of the northern Levant Basin (offshore Lebanon)[END_REF]).The classification of facies associations and the relevant depositional environments is supported by microfacies analysis on 11 samples collected from the outcrop, representing important observations and/or located at bed transition between two facies or two different depositional settings. The main objectives are to understand the microstructural characteristics of the studied sections and their evolution under diagenetic influence, and to reconstruct a depositional model for the studied sedimentary sequence.

Figure 20 .

 20 Figure 20. The classification of porosity in sedimentary carbonates proposed by[START_REF] Choquette | Geologic Nomenclature and Classification of Porosity in Sedimentary Carbonates[END_REF].

Figure 21 .

 21 Figure 21. Petrographic overview of S1 to S11 samples from Kfarhelda outcrop. VP: Vuggy porosity; IP: Intergranular porosity; CC: Calcite cement; IcP: Intercrystalline porosity. S1 -Dolomite with Fe content; S2 -Bioclastic mudstone; S3 -Mudstone with cherts; S4 -Packstone with dolomite rhombs; S5 -Rudstone with vuggy porosity; S6 -Bioclastic packstone with cemented molds and intergranular porosity.

Figure 21 (

 21 Figure 21 (continued). S7 -Rudstone with packstone matrix; S8 -Dolomitized wackestone/packstone with vuggy porosity; S10 -Nonplanar dolomite with calcite cement, intercrystalline and vuggy porosity; S11 -Breccia with bioclasts and vuggy porosity.

Figure 23 .

 23 Figure 23. A sketch illustrating the proposed ramp depositional setting for the Cenomanian -Turonian carbonate platform studied in Kfarhelda north Lebanon, representing Sannine and Maameltain formations.

Figure 24 .

 24 Figure 24. Photographs from Kfarhelda outcrop showing the inner ramp facies association (FA1): (a) marly limestone of facies F1b, (b) mudstone with chert nodules of facies F1c, and (c) bioclastic packstone of facies F1d.

Figure 25 .

 25 Figure 25. Photographs from Kfarhelda outcrop showing the shallow marine platform facies association (FA3): (a) rudist-rich rudstone of facies F3a, (b) boundstone with red algae of facies F3a, and (c) medium crystalline dolomite of facies F3d.

Figure 26 .

 26 Figure 26. A photograph from Kfarhelda outcrop showing breccia (F4a) from the Mid-ramp facies association (FA4).

  One fieldwork campaign is conducted in September 2021 to study the sedimentologic and acoustic properties of the Kfarhelda outcrop. This study focuses on the upper part of Sannine Fm and the overlying Maameltain Fm. A detailed sedimentary description is completed for the 400 m-thick sedimentary section including lithology and texture description of each bed. The depositional-textural classification of rocks is based on Dunham (1962) classification, bioclastic content, and outcropping diagenetic features. -The generation of the synthetic seismogram is based on velocity values measured directly on the outcrop and density values measured in the laboratory for the collected samples. Although the data resolution is different for velocity and density values (419and 44 measurements respectively), the approach of using density values from rock samples and velocity values from outcrop measurements is relevant since low frequency wavelet is used to generate the seismogram. Centimetric changes in microfacies and petrophysical properties of outcrop rocks causes contrasts in acoustic impedance, thus, in reflection coefficients. These contrasts are not directly related to the generation of seismic reflectors, but rather to the amplitude strength and polarity of the seismic trace[START_REF] Nichols | Sedimentology and Stratigraphy[END_REF].Paper Title: Seismic characterisation of Cenomanian -Turonian carbonate platform based on sedimentological and geophysical investigation of onshore analogue outcrop (

  porosity and density values are measured on representative samples in the laboratory. The constructed low frequency synthetic seismogram (25 Hz) is used to compare geological information from the outcrop with the onshore seismic data. This paper aims to (1) identify the relative control of facies distribution and lithological variations on the generation of seismic reflectors and (2) correlate outcrop data with onshore seismic data to identify the seismic signature of stratigraphic sequences.

Figure 27 .

 27 Figure 27. (a) Simplified geological map of Lebanon showing the trace of the onshore seismic profile, and the location of the study area and available onshore wells (edited after CNRS-Lebanon; Dubertret 1955; Nader 2011). (b) Simplified chronostratigraphic chart for onshore Lebanon showing the principal formations and sedimentary facies in north Lebanon from Upper Jurassic to Upper Cretaceous.

Figure 28 .

 28 Figure 28. Panoramic view of the Kfarhelda outcrop, northern Lebanon, showing the identified facies associations. Black lines inside each facies association represent the bedding. Points 0 and 419 m represent the first and the last studied points, respectively.

Figure 29 .

 29 Figure 29. Cenomanian -Turonian facies of Kfarhelda outcrop: (a) bioclastic wackestone; (b) mudstone with chert nodules; (c) mudstone with stylolites; (d) bioclastic floatstone; (e) sedimentary breccia; (f) rudist-rich rudstone; (g) red algae boundstone; (h) dolomite with cemented vugs; (i) bioclastic rudstone; (j) channel facies.

Figure 29 .

 29 Figure 29. Simplified sedimentological log of Kfarhelda outcrop for Cenomanian -Turonian carbonate platform representing supratidal/inner ramp, outer ramp, shallow marine platform, and mid ramp facies associations.

Figure 30 .

 30 Figure 30. Simplified sedimentological log of Kfarhelda outcrop for Cenomanian -Turonian carbonate platform representing supratidal/inner ramp, outer ramp, shallow marine platform, and mid ramp facies associations.

Figure

  Figure 32. High resolution seismic stratigraphy showing a simplified sedimentary log and the relative fracturing intensity; Velocity values at outcrop scale (m/s); Porosity (%), mineral and

Figure 33 .

 33 Figure 33. (a) Satellite image of Kfarhelda area showing the locations of seismic line trace, studied outcrop, and the relative location of seismic facies S1; (b) Cropped image from central part of the interpreted seismic profile SLEB-2D-01-13 showing the key reflectors near the Kfarhelda outcrop, and the location of the studied outcrop.

6. 5

 5 .2. Geological origin of seismic reflectors Based on our data set and the synthetic seismic computation, the geological origin of seismic reflectors has been determined. Seismic reflections can be classified in three groups: (1) high amplitude reflectors resulting from vertical variation in petrophysical properties enhanced by diagenetic features (R1, R2, R3), (2) high-to-moderate amplitude reflectors resulting from a vertical change in acoustic impedance (AI) at the boundary between two facies or FA (R4, R5, R6, R7 and R12) and (3) low amplitude reflectors within karstified and fractured units (R9, R10, R11).

  H1 represents the ground horizon and shows an increase in altitude eastwards with minor elevation near the study area. H15 is a continuous reflector with strong impedance present in the western part of the profile. It corresponds to the base of Albian-Cenomanian limestone of Hammana formation. The reflector H14 is also continuous with high impedance contrast that runs parallel to H15 just below Kfarhelda outcrop where it forms a mound-like feature dipping to the west. H14 limits the boundary between overlying parallel to sub-parallel continuous seismic package and the underlying sub-parallel, less continuous reflectors of high amplitude. The H15-H14 interval has an average thickness of 230 m which coincides with the thickness of Abeih and Mdairej Formations (Figure27b).H13 is a discontinuous reflector that underlies H14 at some places in the middle of the profile, whereas it forms a thin seismic package in the eastern part of the profile, characterized by continuous high amplitude reflectors. The thickness of this unit may be correlated with Chouf formation. H10 and H6 are strong non-continuous reflectors that extend from the centre of the profile eastward, with high impedance contrast. H10 underlies a thick seismic package in the east, below Mount Lebanon, whereas it shows elevation and discontinuity towards the centre.It then thins westward and becomes parallel to H13. H10 corresponds to Kesrouane formation (marly deposits) with average thickness H13-H10 between 810 and 1190 m in the west and thickens eastward.Finally, H6 is more continuous in the central and western parts of the profile marking the base of a similar seismic package. The interval H10-H6 has a thickness between 870 and 1300 m, thickening eastward. It corresponds to Early-Mid Triassic evaporites (Kurrachine anhydrites) considering that the Liassic and Triassic sequences have a total average thickness 1245 m(Nader et al., 2016).

Figure 35 .

 35 Figure 35. (a) Cropped image of the seismic profile, near the studied Kfarhelda outcrop, showing seismic facies and well W1 locations; (b) a cropped image of root mean square (RMS) amplitude and (c) relative acoustic impedance seismic attributes, applied on a section of the profile showing channel facies (circled).

Figure 36 .

 36 Figure 36. Results of well-to-seismic tie using synthetic seismogram, correlated with simplified sedimentological log for the Cenomanian -Turonian succession studied at Kfarhelda [Purple for F1a, dark Brown for F1b, light Brown for F1c, dark Green for F1d, and light Green for F2a]. Synthetic seismic and seismic traces are represented in depth (m). Negative amplitude reflectors are presented in blue, and positive amplitude reflectors are in red. The main seismo-stratigraphic units: (1) Channel facies and (2) Marly limestone zone, are both related to Upper Cenomanian Inner ramp depositional setting.

  ) device. P-wave velocity values were obtained horizontally at 40 kHz frequency with 1 m vertical spacing. The integration of sedimentologic and acoustic properties from outcrop investigation with the petrophysical characterization of samples enabled the generation of a 1D synthetic seismogram convoluted using Ricker wavelet 25 Hz providing a seismic scale resolution. The identified seismic reflectors belong to three groups: (1) high amplitude reflectors resulting from vertical variation in petrophysical properties enhanced by diagenetic features, (2) high-tomoderate amplitude reflectors resulting from a vertical change in acoustic impedance (AI) at the boundary between two facies or FA and (3) low amplitude reflectors corresponding to a highly karstified unit representing homogenized physical properties. The interpretation of the 2D seismic profile, near Kfarhelda outcrop, resulted in better understanding of the subsurface geology. Four seismic facies were identified corresponding to the Early Cenomanian-Turonian Sannine and Maameltain formations. The integration of outcrop and seismic data was done based on synthetic seismogram. The best fit between the synthetic seismogram and the seismic profile resulted in the following conclusions: (1) seismic facies S1 represents the Upper Cenomanian unit of Sannine formation characterized by medium-to-thick bedded limestones with marl intercalations and chert intervals, (2) the main seismic reflectors investigated within S1 are related to the Marly Limestone Zone causing sharp contrast in AI, and the overlying channel facies characterized by bioclastic packstone-floatstone with higher porosity, and (3) near surface reflectors are impacted by noise causing signal distortion. Thus, assessing the geological origin responsible for the reflection and the true thickness of rock unit is less accurate.

  synthetic seismogram is employed to correlate the outcrop and seismic data. Two reflectors are identified representing a zone rich with marly limestone (Marly Limestone Zone) and an overlying porous bioclastic packstone-floatstone unit representing channel facies.

Table 1 .

 1 Thomas et al. (2021) (Table. 1). Facies description of the 2D section from Valanges fm compared to Lithofacies described in[START_REF] Thomas | Contribution of drone photogrammetry to 3D outcrop modeling of facies, porosity, and permeability heterogeneities in carbonate reservoirs (Paris Basin, Middle Jurassic)[END_REF].

	Lithofacies (Thomas et al., 2021)	High Resolution facies	Description
	No facies	1	Hard ground
		2	Fine grainstone with shell debris (bioclasts) and bioturbation
	F2a
		3	Bioturbated fine grainstone
		4	Angular cross-bedded grainstone -fine to coarse grained
	F2b
		5	Flat/fainted cross-bedded grainstone
	F2c	6	Rudstone with large bioclasts
		7	Stylolites
	No facies	8	Fracture/Karst
		9	Vugs

  Figure 14. Photos of different microstructures studied on thin sections: M1 to M5 collected from Valanges section and M6 to M8 from Massangis section. DC: Drusy cement; SOG: Syntaxial overgrowth; BCC: Blocky calcite cement; IP: Intragranular Porosity; GG: Grain-to-Grain contact; InP: Intergranular Porosity; CP: Channel Porosity; VP: Vug porosity.M1 -Ooidal crinoidal grainstone with cemented intergranular porosity and intragranular porosity (F2a) in addition to intense cementation. M2 -Ooidal grainstone with crinoids and gastropods showing intragranular porosity and evidence of grains compaction (F2b). M3 and M4 -Rudstone facies with intragranular and channel porosity (F2c). M5 -Ooid grainstone (F2b) with cement and channel, vug and intragranular porosity. M5 to M6 -packstone (F1c) with important dissolution and vuggy porosity.

Acknowledgements

This thesis work is the result of the codirection between Sorbonne

University, CNRS-Lebanon -National Center for Geophysics, and IFP School. It is co-funded by CNRS-Lebanon through Dawrek'n program, and Campus France (Beirut) as part of SAFAR program. My first thanks go to the previously mentioned establishments which have supervised and funded this thesis work. thank Mr. Cédric Bailly for his contribution to this project, especially in the field work and the petrophysical laboratory measurements. My thanks also go to the Lebanese Petroleum Administration (LPA), for Mr. Wissam Chbat -

Synthetic seismic modelling workflow

Chapter 4: Massangis test case study

Results

Table 2 shows the location of the thin section samples on the outcrop, their corresponding facies, and the description based on field observations. The identified microstructures are presented in Figure 21. The sedimentological investigation of Kfarhelda outcrop is described further in chapter 6. Table 3 represents the classification of Facies Associations (FAs) and their relative facies identified for Kfarhelda outcrop.

Table 2. Characteristics of the analysed thin sections on Kfarhelda outcrop: the elevation on the sedimentary log (Fig. 30), the corresponding sedimentary facies and main the features as described in the field.

Sample Elevation on sedimentary log (m)

Facies Field description F4a Breccia

Table 3. Detailed classification of Facies associations and their relative facies identified for Kfarhelda outcrop (Fig. 28,30).

FA1

Five thin sections are described for the facies associations FA1 representing all the facies types:

F1a, F1b, F1c, and F1d. The sample S1 presents fine crystalline dolomite with iron content forming dense dark mosaic of sub-to planar-s crystals (10 -50 µm). Field observations show laminar intercalations of very fine dolomites, i.e., dolomicrite and iron-rich dolomicrite (Fig. 21). Dolomite facies deposited at the base of the log represent fine crystalline dolomites forming in supratidal (Sabkha) environment prevailing in central-north Lebanon during the Late Cenomanian (Noujaim 1977;Nader et al. 2006).

S2 shows mudstone texture with bioclasts (forams, gastropods). It has mineralogy near to pure calcite and shows small vugs. Similarly, S3 presents mudstone texture, yet it is distinguished by chert content. This sample shows partial dolomite rhombs indicating that dissolution processes have occurred.

The samples S4 and S5 represent the facies F1d (channel facies) characterized by bioclastic content (gastropods, bivalves, rudists). These samples are grain supported; S4 presents packstone microfacies with some rhombic dolomites, and S5 presents rudstone with two types of calcite cement: syntaxial overgrowth predominant during the early stages of burial diagenesis, and blocky calcite cement typically forming during later stages of burial diagenesis.

This sample is also characterized by large vugs suggesting post-sedimentary dissolution phases.

The absence of matrix and other diagenetic processes indicate that the sea level was at its minimum (Salah et al. 2020a).

FA2

The sample S6 represents packstone microfacies (F2a) with high grain content and predominant bioclastic skeletons such as foraminifera, which are mostly well preserved. This sample shows some dissolution porosity as well as cement filled molds. This indicates that a phase of matrix dissolution occurred enhancing the porosity. Dissolution is followed by secondary precipitation resulting in calcite cementation within the molds. The existing microfossils and foraminifera indicate maximum sea level at the time of deposition.

FA3

The samples S7 and S8 represent F3a while S9 and S10 represent F3d. S7 presents rudstone with packstone matrix. Porosity is observed in two forms: microporosity and intergranular porosity resulting from matrix dissolution. Sample S8 presents wackestone/packstone microfacies with development of dolomite rhombs. The rock is partially dolomitized with large vugs resulting from dissolution process.

S9 represents non-planar dolomite crystals with varying crystal size between 50 and 350 µm.

Fragmentation of calcite cement located between crystals can be observed. This facies is characterized by intercrystalline porosity, as well as vuggy porosity resulting from dissolution and erosion of calcite cement within pore spaces. The fragmentation can be related to erosion resulting from the tectonic processes affecting the platform towards the Late Turonian.

Nonplanar dolomite can occur as replacement dolomite. The texture is usually an indicator of development under increasing temperature in burial conditions [START_REF] Folk | Stratigraphy of the Pre-Simpson Paleozoic Subsurface Rocks of Texas and Southeast New Mexico University of Texas[END_REF][START_REF] Radke | On the formation and occurrence of saddle dolomite[END_REF]. The non-planar crystal arrangement can be also an indicator of calcitization process [START_REF] Győri | Dolomitization of shallow-water, mixed silicilastic-carbonate sequences: The Lower Triassic ramp succession of the Transdanubian Range, Hungary[END_REF].

FA4

Finally, the sample S11 represents breccia with bioclastic content. This sample exhibits calcite cementation (syntaxial overgrowth and equant calcite cement), and important dissolution which enhances the porosity by creating large vugs.

Chapter 6: Lebanon study case From 180 to 218 m, FA2 is associated with low porosity and velocities centred between 3800 and 5000 m/s. Between 219 and 231 m, a unit of bioclastic rudstone to grainstone (F3a) is characterized by higher porosity (8%-16%), and velocities lower than 4600 m/s. The velocity is centred between 4000 and 5100 m/s up to 300 m, along with the sedimentary facies' alternation between F3b and F3c. Stylolites are common within F3c, whereas intense fracturing is observed up to 330 m. The porosity appears almost homogenous between 300 and 380 m (∼4.8%-7%), whereas the P-wave velocity shows a scattered pattern. Finally, at the top of the sedimentary log, F4a and F4c present velocity values between 3200 and 6000 m/s, whereas F4b

(bioclastic rudstone to floatstone) present velocities centred between 5100 and 5900 m/s.

Along the previously described sedimentary log, the AI shows a vertical trend similar to that of P-wave velocity. AI is then used to calculate the reflection coefficient and generate a 1D

Seismic facies analysis -cropped section near Kfarhelda

The proposed classification of seismic facies is based on reflection configuration, amplitude characteristics and the continuity of seismic reflectors (Figure 34). The seismic facies type S1 represents continuous parallel reflections with moderate amplitude. The analysis of amplitude suggests a unit of stratified deposits with significant lithological contrast. This can be explained by the presence of limestone layers (high-impedance) intercalated with marls (lower impedance) or marl-limestone alternations within thin beds [START_REF] Słonka | Seismic characteristics and development of the upper Jurassic Carbonate Buildups from the Miechów Trough (Southern Poland)[END_REF]. Such a unit can be related to the Upper Cenomanian unit of Sannine formation characterized by bedded limestones with chert intervals (Nader, 2014;Walley, 1997).

S2 seismic facies type represents semi-continuous wavy parallel reflections with moderate-tohigh amplitude. This type is identified at more than 300 m and the impedance contrast suggests that this unit is related to the massive, bedded limestones (with cherts) of Middle Cenomanian unit of Sannine formation (Nader, 2014;Walley, 1997). The type S3 seismic facies represents a mound-shaped semi-continuous to discontinuous reflection geometry with moderate amplitude.

This lack of continuity is related to carbonate deposits forming reef bodies in a high-energy system [START_REF] Veeken | Seismic stratigraphy and depositional facies models[END_REF]. S3 is identified at 550-640 m which can be related to the reef limestones of Lower Cenomanian unit of Sannine formation.

Finally, seismic facies type S4 overlies the reflector H15 marking the base of Sannine formations at around 650 m depth. S4 represents chaotic and low amplitude seismic reflectors that could be linked to deposits with karst features related to Early Cenomanian massive dolomitic rocks defined as the Hammana-Sannine transition unit. Karst features have been interpreted in terms of seismic facies as chaotic seismic reflections with low amplitude (Burberry et al., 2016;Embry et al., 2021;Hendry et al., 2021;[START_REF] Hu | Quantitative characterization of deep fault-karst carbonate reservoirs: a case study of the Yuejin block in the Tahe oilfield[END_REF]Sayago et al., 2012). This can be related to the petrophysical properties of karstified rocks often characterized by lower AI values compared to the surrounding rock units (Fournillon et al., 2021).

In Kfarhelda outcrop, seismic facies type S1 is dipping westward. It reaches down to 1.15 s (Figure 35a). The interpretation of surface geology, as well as the reflection characteristics, confirms that S1 was observed in other locations to the west of the seismic profile where the Turonian Maameltain formation outcrops. In the Lebanese study case, the interpretation of the 2D onshore seismic profile is completed focusing on a section of the profile representing the studied outcrop. The interpretation is associated with seismic facies and attribute analysis. The results highlight the importance of incorporating the geological and sedimentological knowledge of the outcrop in making robust seismic facies analysis [START_REF] Lanteaume | Testing geologic assumptions and scenarios in carbonate exploration: Insights from integrated stratigraphic, diagenetic, and seismic forward modelling[END_REF]).

In the final step, the correlation of outcrop and seismic data is based on the synthetic seismogram. The position of the studied outcrop is different than that of the 2D onshore seismic profile (Chapter 6, Fig. 35a), where the outcrop is located to the north of the seismic profile in which the area is fault-affected. Consequently, the calibration between the 2D seismic profile and the 1D synthetic seismic appears to be challenging. While it is possible to correlate the seismic reflectors in each case, the prediction of the precise depth and thickness of each layer is not entirely accurate.

The processing of the seismic profile is completed by Spectrum Geo Ltd. following Kirchhoff Pre-stack Time Migration (PSTM). The applied processing techniques including PSTM, noise attenuations, deconvolution, velocity model building, etc., aims to improve the image and enhance the seismic reflections from deep layers. Thus, the processing is mainly dedicated to picture the deepest part of the profile and not the top-most part. The near-surface part of the profile appears to have less image quality and is not precisely adapted to be calibrated with outcrop data. It is therefore recommended that a new processing workflow is completed for the seismic profile dedicated to improving the image quality of the first few hundred meters.

Some of the processing techniques that can be applied include static corrections, near surface modelling, and spectral enhancement. Applying the static corrections to the velocity and elevation differences for the near surface results in better positioning of seismic reflectors [START_REF] Cox | Static Corrections for Seismic Reflection Surveys[END_REF]Mousa and Al -Shuhail 2021).

Near surface modelling such as reflection tomography (described in methodology, Chapter 3) is efficient for accurately imaging the near-surface layers. Finally, applying deconvolution and spectral enhancement techniques helps improving the amplitude and resolution of near-surface reflectors in which they become more distinguishable [START_REF] Choi | Deep learning spectral enhancement considering features of seismic field data[END_REF][START_REF] Jo | Machine learning-based vertical resolution enhancement considering the seismic attenuation[END_REF].

Indeed, these techniques, among others, can be utilized in seismic data processing to enhance