The purpose of this study is to investigate the Upper Tournaisian substage within the Carboniferous carbonate deposits of the Aladag Unit in the Hadim region (Central Taurides) based on foraminiferal diversity and to study the meter scale cyclicity in order to explain the sequence stratigraphic evolution of the carbonate succession. In this study, a 27.01 m thick stratigraphic section consisting of limestones and shales was measured and 89 samples, collected along this section, were analyzed. Micropaleontological analyses are based on benthic foraminifera. According to the benthic foraminiferal assemblages, two biozones were identified as Zone Ut1 and Zone Ut2 within the Upper Tournaisian. Zone Ut1 is characterized by a poor foraminiferal assemblage while the Zone Ut2 consists of a diverse Upper Tournaisian foraminiferal fauna. In order to construct a sequence stratigraphic framework and appreciate depositional environmental changes, microfacies studies were carried out. Seven microfacies types were recognized and depending on the stacking patterns of these microfacies types, two fundamental types of cycles, A and B, were identified. Through the measured section, twenty-five shallowing-upward meter scale cycles and two sequence boundaries were determined. Quantitative analysis of benthic foraminifera was used to demonstrate the biological response to cyclicity. Since foraminifers are very sensitive to sea level changes, the abundance of benthic foraminifera displays a good response to sedimentary cyclicity. In order to apply a worldwide sequence stratigraphic correlation, the sequence boundaries and the meter scale cycles of this study were compared with those described in South China and Western European platform and the Moscow Syneclise. An Early Tournaisian transgression was followed by a major fall in relative sea level during the Late Tournaisian. Two sequence boundaries recognized in the measured section correspond to global sea level falls in the Late Tournaisian.

The SACROC unit is an isolated carbonate platform style of reservoir that typifies a peak icehouse system. Icehouse carbonate platforms are one of the least well understood and documented carbonate reservoir styles due to the reservoir heterogeneities they embody. The current study is an attempt to recognize carbonate rock types defined based on rock fabrics by integrating log and core based petrophysical analysis in high-frequency cycle (HFC) scale sequence stratigraphic framework and to improve our ability to understand static and dynamic petrophysical properties of these reservoir rock types, and there by, improve our understanding of heterogeneity in the middle early to late early Canyon (Canyon 2) high frequency sequence (HFS) in the Northern Platform of the SACROC Unit. Based on core descriptions, four different sub-tidal depositional facies were defined in the Canyon 2 HFS. Identified depositional facies were grouped into three different reservoir rock types in respect to their rock fabrics in order for the HFC scale petrophysical reservoir rock type characteristic analysis. Composed of succession of the identified reservoir rocks, twenty different HFCs were determined within the HFC scale sequence stratigraphic framework. The overall trend in the HFCs demonstrate systematic coarsening upward cycles with high reservoir quality at the cycle tops and low reservoir quality at the cycle bottoms. It was observed in terms of systems tracts described within the cycle scale frame work that the overall stacking pattern for high stand systems tracts (HST) and transgressive systems tracts (TST) is aggradational. And, the reservoir rocks representing the HST are more porous and permeable than those of TST. In addition to that, it was detected that the diagenetic overprint on the HST reservoir rocks is more than that of the TST. According to the overall petrophysical observations, the grain-dominated packstone deposited during HST was interpreted as the best reservoir rock. Upon well log analysis on the identified reservoir rocks, some specific log responses were attributed to the identified reservoir rocks as their characteristic log signatures. / text

This study aims to enlighten microfacies evolution and micropaleontological properties of the Tournaisian &amp / #8211 / Visean boundary in Aladag Unit (Central Taurides, Turkey). Two sections comprising dark shale and dark limestone alternations, including a fairly dolomitized part towards their top are measured. The microfacies analysis suggests a subtidal depositional environment. Foraminiferal assemblages were distinguished at Section AP and biozonation was documented. The biozonation separates the measured section into three zones, described as A, B and C. Zone A is scarce foraminifera fauna, and mainly contains Earlandia sp. Zone B is defined by appearance of a diversified foraminifera fauna and the first appearance of Lugtonia monilis (Malakhova, 1955) with Eoparastaffella sp. (morphotype 1). Zone C is defined according to the first appearance of Eoparastaffella simplex (Vdovenko, 1964) (morphotype 2) and foraminifers Laxaendothyra ex. gr. laxa. Tournaisian &amp / #8211 / Visean boundary is defined at the 60th sample, due to appearance of Eoparastaffella simplex (Vdovenko, 1964) (morphotype 2). Seven microfacies types in section AP, and six microfacies types in section PA are identified and, the intensely sampled part of the measured section AP is separated into 13 shallowing upward meter-scale cycles. These cycles, showing subtidal character are detected by both repetitions of microfacies and changes in abundance of foraminifers. A contrasting evaluation of the Tournaisian &amp / #8211 / Visean boundary of Taurides with Guangxi, South China and Dinant, Belgium is presented. The Chinese stratotype contains a diverse, more complete fauna of Tournaisian - Visean foraminifera, while the Belgium and Turkish sections are scarcer and most probably facies controlled.

Through a discipline termed “comparative sedimentology”, modern carbonate depositional environments have been used extensively as analogs to aid in the interpretation of equivalent fossil systems. Using field samples, GIS and remote sensing data for three isolated carbonate platforms in the Pacific, this thesis seeks to examine relationships between grain texture and grain type and their environment of deposition. The motivation is to highlight relationships that have the potential to better understand facies relations on carbonate platforms, and thereby reduce uncertainty and increase accuracy of subsurface exploration. The results of this study show that on Raivavae, Tubuai, and Bora Bora: French Polynesia grain texture and type of collected sediment samples could be used to predict water depth and relative distance lagoonward from the reef rim with ≥ 73% and ≥ 67% accuracy, respectively. The predictive relationships; however, were largely site specific. The exception being that the same relationship between water depth and the abundance of mud and coral could be used on both Raivavae (accuracy = 81%) and Tubuai (accuracy = 78%). Additionally, the abundance of coral and Halimeda in sediment samples were able to classify samples as belonging to either the platform margin or platform interior environments on Raivavae, Tubuai, and Bora Bora with 75%, 65%, and 65% accuracy, respectively. Overall, the results of this study suggest that the abundance of coral holds potential to be utilized as a proxy for distance from the reef rim on modern and ancient isolated carbonate platforms dating back to the Miocene geological epoch.

Sediment on Cay Sal Bank (CSB) is characterized by its coarse-grain size, poor sorting, predominance of skeletal fragments, and relatively depleted d18O isotope values. CSB is an incipiently drowned platform in close proximity to the Great Bahama Bank (GBB), a carbonate platform which is not incipiently drowned and characterized by fine-grained, non-skeletal sediment. The GBB has locally well-developed oolitic grainstone facies and coral reef margins, which are both lacking on CSB. Platform-top water depths on the GBB are typically 10 m or less, but CSB depth ranges between 7 and 30 m. CSB is devoid of mud, whereas mud-supported depositional texture on GBB comprises 28% of the dataset. Dominant non-skeletal grains are grapestones and pelletoids, and the latter display evidence of micritization. Non-skeletal types on GBB are primarily grapestones and ooids. Surficial sediments from both platforms are primarily composed of aragonite, but high-magnesium calcite is slightly more prevalent on CSB. Similar to other incipiently drowned platforms in the Caribbean, CSB has been subject to rapid Holocene flooding. Common features between these three platforms are a thin sedimentary cover, a dominance of Halimeda plates, and micritized cryptocrystalline grains. Increased nutrient levels have been shown to be related to platform drowning as well as the reduction of coral and algal growth on Serranilla Bank, but rapid Holocene flooding has been more likely for CSB, and appears to be in the second of a three-stage drowning process, ultimately culminating in carbonate platform “turn off”, preventing further carbonate and reef development at the level of GBB.

An appreciation of the extent of syndepositional fracturing, faulting, and cementation of carbonate platform margins is essential to understanding the role of early diagenesis and compaction in margin deformation. This study uses integrated lidar and outcrop data along the Capitan Reef from an area encompassing the mouths of both Rattlesnake and Walnut Canyons. Mapping geomorphic expressions of syndepositional faults and fractures at multiple scales of observation was the main approach to delineating zones of syndepositional fractures. Ridge- groove couplets visible in exposures of the Capitan Reef throughout the Guadalupe Mountains were targeted because the ability to identify these as signs of syndepositional fracture development would have implications for the entire reef complex. Results show that these ridgegroove couplets are the product of differential weathering of syndepositional as well as burial-related fractures. Recessive grooves have an average syndepositional fracture spacing of ~13 m whereas ridges have a spacing of ~33 m. vi Smaller (~5-20 m-wide) scale erosional lineaments common in the study area and mappable on airborne lidar are formed by differential erosion of planes of syndepositional faults. Maps of these fault lineaments on the lidar show that syndepositional faults extend laterally for 300 m - 2000 m and relay near the terminations of the faults at each end. Faults can be further grouped into fault systems consisting of sets of faults connected by fault relays that extend for at least the entire length (~12 km) of the study area. Although vertical displacement along faults is typically less than 11 m, syndepositional faults result in changes in structural dip domain of 1-6 degrees across an individual fault. Even smaller erosional lineaments (10 cm-1 m) are visible on the airborne lidar that form as a result of differential erosion of individual fractures. Larger fractures (> 20 cm) can be reliably mapped on the lidar, but smaller features (< 20 cm) cannot be reliably mapped with currently available data and can only be captured using field studies. Fracture fill types are heterogeneous along strike as shown by comparisons of field study locations. Siliciclastic-dominated fills are likely sourced from overlying siliciclastic units of the shelf, which, in this area, were from the Ocotillo Siltstone. These silt-filled fractures are broadly distributed, indicating preferential development and infill of syndepositional fractures during the deposition of the Ocotillo Siltstone in the G27/28 high-frequency sequences. Development of early fractures is also shown to have been influenced by mechanical stratigraphy with changes in fracture spacing between massive to thick-bedded shelf-margin (~17 m fracture spacing) and outer-shelf facies tracts versus thin-bedded outer-shelf and shelf-crest (~28 m fracture spacing). Ultimately, this study demonstrated that the Capitan shelf margin was ubiquitously overprinted by syndepositional fracturing and faulting and that this nearsurface structural modification influenced early diagenetic patterns and internal vii sedimentation throughout the reef margin. Before this study, the extent and nature of syndepositional fracture/fault development within the margin were largely unquantified. Here, by integrating field observations and surface weathering reflections of these fractures as observed in the lidar, we can demonstrate a widespread impact of early fracturing more akin to analogous early-lithified margins such as the Devonian of the Canning Basin of Australia. / text

Au Crétacé inférieur, l'intense activité magmatique due à la dislocation du super-continent Pangée influence fortement les conditions environnementales globales. Au Barrémien terminal et Aptien basal, période géologique dont fait l'objet cette étude, le bassin Vocontien, puis Bédoulien, recouvre le Sud-Est de la France, sous un climat chaud et humide. Sur les bordures de ces bassins, des plateformes carbonatées se mettent en place. Les sédiments qui se déposent sur ces plateformes sont à l'origine de la formation urgonienne. Afin d'étudier cette formation, une charte biostratigraphique, principalement basée sur les Orbitolinidés, et un modèle de faciès ont été développés. Les assemblages faunistiques, la succession des faciès, les observations de terrain ainsi que l'étude de signaux géochimiques ont permis le découpage séquentiel de la série urgonienne le long de 54 coupes et puis, répartis sur l'ensemble du Sud-Est de la France. Les corrélations induites par cette étude stratigraphique ont mis en évidence d'importantes variations d'épaisseur et d'environnements de dépôt au sein même de la plateforme urgonienne. Ces variations sont expliquées par le jeu de failles syn-sédimentaires qui ont compartimentées la plateforme urgonienne en blocs. Sur la bordure sud du bassin Vocontien, ces failles d'orientation N30° et N110° délimitent six blocs basculés. Au sommet du Barrémien terminal, la subsidence des blocs situés le plus au sud s'amplifie jusqu'à provoquer l'ouverture du bassin de la Bédoule au sud du secteur d'étude. Cette théorie d'évolution a ensuite été testée par l'élaboration d'un modèle numérique en trois dimensions de l'Urgonien du Sud-Est de la France. Sa cohérence avec les données acquises tout au long de cette étude d'une part, et sa cohérence géométrique d'autre part, valide les théories avancées. Des analogues de l'Urgonien sont répartis dans le monde entier et notamment au Moyen-Orient où ils représentent d'importants réservoirs pétroliers. Être capable de caractériser les facteurs ayant influencé l'architecture de l'Urgonien du Sud-Est de la France permet par la suite une meilleure exploitation de ses ressources énergétiques. / During the Early Cretaceous epoch, intensive magmatic activity due to the dislocation of the super-continent Pangaea, highly influenced global environmental conditions, which were characterized by a warm and generally humic climate. In this context, carbonate platforms were important in tropical and subtropical shallow-water regions, and especially during the late Barremian and early Aptian, platform carbonates of so-called Urgonian affinity are widespread. In southeastern France, the Urgonian platform was part of the northern Tethyan margin and bordered the Vocontian and the Bedoulian basins. The goal of this thesis was the systematic study of the Urgonian Formation in this region, and in order to achieve this goal, a biostratigraphic chart and a facies model were developed. The faunistic assemblages, the facies succession, the field observations and the study of geochemical signals lead to a sequential subdivision of the Urgonian series along 54 sections and wells allocated in five different regions in southeastern France (Gard, Ardèche, Vercors, Vaucluse and Provence). Correlations from this stratigraphic study highlight important variations in thickness and depositional environments of the Urgonian series. These variations are explained by relative movements induced by syn-sedimentary faults, which divided the Urgonian platforms into blocks. On the southern border of the Vocontian basin, these faults, oriented N30° and N110°, delineate six tilted blocks. At the top of the upper Barremian carbonates, subsidence of the two southern blocks accelerated leading to the opening of the Bedoulian basin. The reconstruction of the sequence-stratigraphic and paleoenvironmental evolution of the Urgonian platforms was then tested by the construction of a 3D numerical model of the Urgonian formation of southeastern France. Firstly, its consistency with the data collected during this study, and secondly, its geometrical coherence validate the proposed theory. Urgonian analogs exist all over the world and particularly in Middle East where they constitute important oil reservoirs. The exact reconstruction of the major factors, which influenced the architecture of these formations, will allow for a better exploitation of these energy resources.

Remote sensing has transformed coral reef science in the last decades. It is now possible to audit reef health and geomorphology at global scale and very high spatial resolution. This work utilizes the vast and no-cost archive of imagery housed within Google Earth (GE). GE was used to interrogate the morphometric properties (size, shape, complexity, etc) of the components that combine to yield a reef environment (reef structures, sediment sheets, and so forth). The data populated a morphometric database for reefs globally that are partitioned by their architecture. The database has been investigated using information theory. The aim of the work is to identify whether motifs of carbonate platforms within these reef types are predictable on the basis of environmental parameters. The results are relevant to assess depositional patterns to develop rules for predicting how facies are distributed in modern systems and ancient reservoirs.

Spur and groove (SaG) morphology is a common ornamentation of reef-armored Holocene carbonate platform margins. Composed of margin-normal promontories constructed of coral framestone, termed “spurs”, interleaved with similarly orientated gullies, “grooves”, this morphology varies based on a host of physical controls. Primarily, the surrounding oceanographic conditions as well as the size and shape of the platform the SaG is encompassing, directly influence the development and organization of SaG. Since grooves act as conduits for carbonate sediment transport, this study seeks to examine the relationship between SaG organization dictated by platform size and shape and how that in turn influences platform-top sedimentation. The analysis reveals trends that suggest platform shape plays a larger role than platform size in allowing highly organized SaG to develop on multiple margins around the platform. In turn, those trends would suggest these sites to have more stable platform top sediment deposits. However, many variables go in to the creation and maintenance of platform top cays. While this study enhanced the current understanding of how oceanographic conditions influence SaG development and organization, expanding on the concepts and results found in this study coupled with coring data of SaG and platform-top cays, could further link the connection between SaG and sediment transport.

Les objectifs de cette thèse sont (1) de définir les facteurs contrôlant le développement à grande échelle des plateformes carbonatées intracratoniques et (2) de relier la diagenèse précoce des discontinuités avec les paléoenvironnements et les modèles de stratigraphie séquentielle. L’évolution de la plateforme carbonatée de l’ouest de la France a été reconstituée de l’Aalénien à l’Oxfordien (17 millions d’années). La topographie du socle contrôle la répartition latérale des bathymétries jusqu’au Bathonien moyen. La tectonique régionale favorise ou empêche localement la production carbonatée. À l’échelle des bassins ouest-téthysiens, des phases généralisées de disparition et de croissance des plateformes carbonatées sont contrôlées par les variations du climat d’une période de 9 millions d’années. La production carbonatée est faible pendant les périodes humides et importante au cours des périodes sèches perturbées par de courtes moussons. Des analyses isotopiques (δ18O et δ13C) à haute résolution ont été réalisées sur des ciments précoces variés localisés sous des discontinuités, permettant de reconstituer l’histoire paléoenvironnementale aboutissant à leur formation. Les ciments en dents de chien ainsi que les ménisques et enveloppes micritiques analysées ont précipité directement en calcite faiblement magnésienne dans l’eau de mer. Un nouveau modèle reliant architecture, stratigraphie séquentielle, faciès et diagenèse précoce est proposé pour une bordure de plateforme oolithique. Sur la plateforme interne, les discontinuités passent latéralement de surfaces subaériennes à des hardgrounds marins, dont l’érosion aboutit au dépôt de niveaux à intraclastes sur la bordure de plateforme. La cimentation précoce est uniquement localisée sous les discontinuités et est absente dans la bordure de plateforme où la sédimentation est continue. / The objectives of this thesis are (1) to characterize the factors controlling the large-scale development of intracratonic carbonate platforms and (2) to link early diagenesis of discontinuities with palaeoenvironments and sequence stratigraphy models. The evolution of the western France carbonate platform is reconstructed from the Aalenian to the Oxfordian (17 million years). The basement topography controls bathymetries until the mid-Bathonian. Regional tectonics promotes or prevents locally carbonate production. General stages of carbonate platform growth and demise in western Tethyan basins are controlled by 9 million years’ climatic variations. Carbonate production is low during humid intervals and high during dry intervals disturbed by short periods of intensive rainfall. High resolution isotopic analyses(δ18O and δ13C) were performed on various early cements located below discontinuities to reconstruct the palaeoenvironmental conditions leading to their formation. Dogtooth cements, micritic meniscus and envelopes precipitated in low-magnesium calcite directly in seawater. A new model, linking architecture, facies, sequence stratigraphy and early diagenesis is proposed for an oolitic platform wedge. On the inner platform, discontinuities change laterally from subaerial surfaces to marine hardgrounds, whose erosion leads to the deposit of an intraclasts level on the platform wedge. Early cements are only located under discontinuities and are absent in the platform wedge because of a continuous sedimentation rate.