The late Middle Jurassic (Callovian) Entrada Sandstone has been divided into two general facies associations consisting primarily of eolian sandstones in eastern Utah and "muddy" redbeds in central Utah. Sedimentary structures within the redbed portion are explained by the interfingering of inland sabkha, alluvial, and eolian depositional systems. A complete succession from the most basinward facies to the most terrestrial facies in the Entrada Sandstone consists of inland sabkha facies overlain by either alluvial or eolian facies. Where both alluvial and eolian facies interfinger, alluvial facies overlain by eolian facies is considered a normal succession. Sequence boundaries, often identified by more basinward facies overlying more landward facies, are observed in the Entrada Sandstone and are extrapolated for the first time across much of Utah, including both the eolian-dominated and redbed-dominated areas. Using these sequence boundaries as well as recent tephrochronologic studies, three time correlative surfaces have been identified in the Entrada. Based on the facies interpretations at each surface, five paleogeographic reconstructions and five isopach maps have been created, illustrating two major intervals of erg expansion and the location of the Jurassic retroarc foreland basin's potential forebulge. Eolian (erg-margin) sandstones pinch-out into muddy redbeds creating combination traps, as evidenced by dead oil (tar) and bleached eolian sandstone bodies within the Entrada. The Entrada Sandstone is a world-class analog for similar systems, such as the Gulf of Mexico's Norphlet Sandstone, where eolian facies grade into muddy redbed facies.

O Subgrupo Itararé apresenta o registro sedimentar mais expressivo da glaciação que assolou a Bacia do Paraná durante o Neopaleozóico. Próximo à borda leste da bacia, em especial na área do estudo, entre os municípios de Sorocaba e Itapetininga, este registro é caracterizado basicamente por depósitos glaciomarinhos, representativos de períodos de mar relativamente mais baixo intercalados com registros de mar relativamente alto. Através da definição e análise de fácies foi possível identificar, na área do estudo, 15 (quinze) unidades faciológicas: Diamictito maciço compactado, Diamictito maciço não compactado, Diamictito maciço compactado deformado, Diamictito tabular, Diamictito lenticular, Arenito maciço tabular, Arenito maciço lenticular, Arenito com estratificação gradacional, Arenito com estratificação cruzada e granodecrescência ascendente, Arenito com estratificação cruzada de baixo ângulo e truncamentos, Siltito maciço, Siltito maciço com clastos dispersos, Folhelho ou argilito maciço, Folhelho ou argilito maciço, com clastos dispersos e Interlaminado. A análise dessas fácies, bem como seu agrupamento em associações diagnósticas (AF1, AF2, AF3 e AF4), permitiu o reconhecimento de tratos de sistemas deposicionais, TSMB, TST, TSMA e TSRGi, os quais, por sua vez, levaram à identificação de 9 (nove) seqüências de 3ª ordem, que permitiram o estabelecimento um arcabouço cronoestratigráfico para os sedimentos do Subgrupo Itararé, ao longo do perfil selecionado na área do estudo. Para se realizar a correlação pretendida entre os sedimentos do Subgrupo Itararé na área do estudo e os aflorantes na região localizada ao sul do Arco de Ponta Grossa no Paraná e Santa Catarina, foram identificados planos ou horizontes que podem ser utilizados, segundo suas características, como datum litoestratigráfico e datum bioestratigráfico. Os resultados das análises palinológicas, bem como os próprios dados físicos de superfície, demonstraram confiabilidade e viabilidade de correlação. A análise petrográfica efetuada em quatro amostras de arenitos revelou porosidades da ordem de 8 a 13%, o que permitiu caracterizar esses sedimentos como potencialmente bons para reservatórios relativamente a hidrocarbonetos ou aqüíferos. / The Itararé Subgroup (Carboniferous-Permian) of the Paraná Basin of southeastern Brazil contains the thickest, most extensive and one of the longest records of late Paleozoic glaciation in all of the Gondwana supercontinent. In the studied area, situated between the cities of Sorocaba and Itapetininga, São Paulo State, this record is characterized by glaciomarine sediments depicting intercalation of periods of high and low relative sea-level. Facies analysis of the glacigenic sediments allowed the identification of 15 lithofacie units: compact massive diamictite, massive non compact diamictite, massive non compact deformed diamictite, tabular diamictite, lenticular diamictite, massive tabular sandstone, massive lenticular sandstone, sandstone with gradational bedding, sandstone with cross bedding and normal grading, sandstone with low angle cross bedding and truncations, massive siltstone, massive siltstone with clasts, massive shale or mudstone, massive shale or mudstone with dispersed clasts and laminites. The analysis of facies and their clustering into the associations AF1, AF2, AF3 and AF4 enabled the identification of the systems tracts TSMB, TST, TSMA and TSRGi and 9 sequences of 3rd order. These provided the base to set up a local chronostratigraphic framework for the Itararé Subgroup in the studied area. In view of the possibility of correlation between the sediments of the studied area and those outcropping in the south of the Ponta Grossa arch, in the States of Paraná and Santa Catarina, some datum planes were determined. The results of the palinological analysis as well as the surface data surveyed pointed out that this correlation is feasible. Petrographic analysis of 4 samples of sandstones indicated porosities between 8 and 13 % which characterize them as potentially reservoirs for water and hydrocarbon.

A influência da tectônica do supercontinente Gondwana é registrada no Gráben Arroio Moirão (RS), um relicto sedimentar associado ao Triássico da seção contínua da Bacia do Paraná, preservado sobre o Escudo Sul-Riograndense. Entretanto, o gráben dista 150 km da seção contínua e não apresenta nenhuma correlação estratigráfica clara. Baseado em novos dados sedimentológicos, paleontológicos e em abordagem de estratigrafia de sequências nova, se propõe um arcabouço estratigráfico para o Gráben Arroio Moirão e a sua correlação com a seção contínua da Bacia do Paraná. O gráben é composto pelo empilhamento de sequências de alta frequência, com granodecrescência ascendente, definido como flood units em um modelo de leques terminais. O conteúdo fossilífero corresponde à Sequência Candelária de idade Carniana, e estratigraficamente corresponde aos depósitos proximais da bacia triássica relacionados ao Escudo. As unidades do gráben estão em contato direto com o embasamento e está superfície representa um pulso de soerguimento, que erodiu as sequências anteriores, seguido por um rebaixamento que registrou a Sequência Candelária. A reativação das estruturas herdadas do embasamento é relacionada à orogenia triássica na margem sudoeste do Gondwana e responsável pelo controle deposicional dentro do Gráben Arroio Moirão. / The influence of Gondwana tectonics in the Triassic is registered in the Arroio Moirão Graben, a relict sedimentary unit associated with the Triassic section of Paraná Basin, preserved over the Sul-Riograndense Shield. However, this graben is 150 km far from the Paraná Basin and has no clear stratigraphic correlation with the main Triassic outcropping area. Based on new sedimentological, paleontological and sequence stratigraphy analysis, we propose a sequence stratigraphy framework for the graben units and correlation with the Triassic section of Paraná Basin. The graben has a stacking of high-frequency sequences with fining upward trend, defined as flood units in a Terminal Splay model. The fossil content corresponds to the Hyperodapedon assemblage zone with Carnian age. These sequences are correlated with Candelária Sequence from Paraná Basin and represent a more proximal facies-association related with a source-area from the shield. The graben units are directly overlying the basement units and this surface registers an uplift that eroded the previous sedimentary record of Paraná basin followed by a Middle Triassic basin wide subsidence. The reactivation of inherited structures from the basement was related to the southern Gondwana orogeny in Middle to Late Triassic that controlled the deposition in the Arroio Moirão Graben.

The aim of this study is to investigate the Upper Visean substages, delineate the Visean - Serpukhovian boundary with calcareous foraminifera and interpret the foraminiferal evolution and sequence stratigraphical framework by using sedimentary cyclicity across the boundary section. For this purpose a 59,61 m thick stratigraphic section consisting of mainly limestone and partly sandstone and shale is measured in the Aziziye Gedigi and Oru&ccedil / oglu Formations in the Pinarbasi Region of Eastern Taurides. A detailed micropaleontological study has revealed presence of important foraminiferal groups namely, parathuramminids, earlandiids, endothyroids, archaediscids, biseriamminids, fusulinids, loeblichids, tournayellids and paleotextularids and 145 species and three biozones. The biozones are, in ascending order, Eostaffella ikensis &ndash / Vissarionovella tujmasensis Zone (Mikhailovsky / Late Visean), Endothyranopsis cf. sphaerica &ndash / Biseriella parva Zone (Venevsky / Late Visean) and Eostaffella pseudostruvei &ndash / Archaediscids @ tenuis stage Zone (Taurssk / Early Serpukhovian). A detailed microfacies analysis was carried out in order to understand the depositional history and sedimentary cyclicity and construct the sequence stratigraphic framework of the studied area. Three main depositional environments consisting of open marine, shoal or bank and tidal flat environments were interpreted based on the analysis of 12 major microfacies and 11 sub-microfacies types. Based on the vertical association of microfacies twenty-six cycles, two sequence boundaries and three sequences were recognized in the studied section and these two sequence boundaries, which correspond to the Mikhailovsky and Venevsky horizons, are the records of the global sea level changes during the Late Paleozoic Ice Age. Within this context Visean &ndash / Serpukhovian boundary falls in the transgressive system tract of the third sequence. The duration of cycles are calculated as 117 ky and interpreted as orbitally induced glacioeustatic cycles.

Linking diagenesis to depositional facies and sequence stratigraphy enables better prediction of spatial and temporal distribution of diagenetic alterations, and thus of evolution of reservoir quality in sandstones. This thesis demonstrates that employing this approach is possible because depositional facies and sequence stratigraphy can provide useful information on parameters controlling the near-surface diagenesis, such as changes in: (i) pore-water chemistry, (ii) residence time of sediments under certain geochemical conditions, (iii) detrital composition and proportion of extra- and intra-basinal grains, and (iv) types and amounts of organic matter. Evidence from four case studies enabled the development of conceptual models for distribution of diagenetic alterations and of their impact on evolution of reservoir quality in sandstones deposited in paralic, shallow marine and fluvio-lacustrine environments. Diagenetic alterations that have been constrained within the context of depositional facies and sequence stratigraphy include: (i) carbonate cement (microcrystalline and equant calcite spars dolomite over poikilotopic calcite), pyrite and glaucony are most abundant in progradational braid-delta fan sequences, particularly along the topsets (i.e. maxiumum flooding surface, MFS) and along parasequences boundaries in the deltaic facies of the early highstand systems tract HST, (ii) cementation by coarse spar calcite, dolomite, and the formation of moldic porosity by the dissolution of framework carbonate grains are most abundant in the aggradational fan deltas sequences, (iii) eogenetic kaolinitization of framework silicates is largely restricted to the fluvial and paralic HST sandstones, whereas telogenetic kaolinite may occur in the transgressive systems tract TST sandstones too, (iv) formation of goethite ooids in the TST sediments, (v) formation of glaucony, siderite spherules, and extensive grain-coatings, grain-replacing and ooidal berthierine, more in the TST than in the HST sediments, particularly below the transgressive surface TS and MFS, (vi) cementation by calcite with (δ18OV-PDB = -11.5‰ to -5.4‰) and Fe-dolomite/ankerite (δ18OV-PDB = -10.8‰ to -9.6‰) occurs in both TST and HST sandstones, (vii) syntaxial quartz overgrowths are most extensive in the HST sandstones owing to the presence of incomplete grain-coating berthierine/chlorite, (viii) greater amounts of micro-porosity in the TST sandstones than in the HST sandstones are related to the greater amounts of berthierine/chlorite in the former sandstones, and (ix) chlorite rims around quartz grains retarded the precipitation of quartz overgrowths, and hence prevented a greater loss of primary intergranular porosity in fluvio-lacustrine sandstones. Therefore, constraining the distribution of diagenetic alterations in the contexts of depositional facies and sequence stratigraphic context is a powerful approach to be used in hydrocarbon exploration.

An integrated micropaleontological, mineralogical and sequence stratigraphical investigation was carried out across the Cretaceous/Paleogene (K/P) boundary in the Haymana basin, Turkey. A 29.41 m thick boundary section consisting of limestones and marls was measured and 90 samples were analyzed. Biostratigraphic and chronostratigraphic works are based on the planktonic foraminifera. 64 planktonic species were identified and 5 biozones were established. The biozones are, in ascending order, Planoglobulina acervulinoides zone, Racemiguembelina fructicosa zone, Pseudoguembelina hariaensis zone for the Late Maastrichtian / Guembelitria cretacea (P0) zone and Parvulorugoglobigerina eugubina (P1a) zone for the Early Danian. In order to detect the mineralogical changes across the boundary bulk and clay minerals were analyzed using X-ray diffractometry (XRD). Calcite, quartz,feldspar and the clay minerals composed of smectite (montmorillonite) and chlorite are the main components of the rocks. A decrease in calcite and an increase in the detrital minerals (quartz, feldspar) and the clay minerals were detected in the boundary beds. In order to find out the depositional history of the area a detailed microfacies study was performed and 10 microfacies type were determined. The microfacies types defined correspond to slope to basin environment. Based on microfacies analyses, the sequence stratigraphic framework of the boundary beds was constructed. K/P boundary beds were recorded in the transition of transgressive systems tract to highstand systems tract, coinciding with a maximum flooding surface. These beds show a similar pattern with many other K/P boundary beds in different locations of the world indicating eustatic sealevel variations overprint the tectonic control in the basin.

The aim of this study is to establish the planktonic foraminiferal biozonation, to construct the sequence stratigraphical framework and to determine the foraminiferal response to sedimentary cyclicity in the sedimentary sequence spanning Upper Cretaceous-Paleocene in the Haymana basin (Central Anatolia, Turkey). In order to achieve this study, the stratigraphic section was measured from sedimentary sequence of the Haymana, Beyobasi and YeSilyurt formations. The sedimentary sequence is mainly characterized by flyschoidal sequence that is composed of alternating of siliciclastic and carbonate units. On the account of the detailed taxonomic study of planktonic foraminifers, the biostratigraphic framework was established for the Maastrichtian-Paleocene interval. The biozonation includes 7 zones / Pseudoguembelina hariaensis, P&amp / #945 / , P1, P2, P3, P4 and P5 zones. The Cretaceous-Paleogene (K/P) boundary was delinated between the samples HEA-105 and 106. In order to construct the sequence-stratigraphical framework, the A, B, C and D-type meter-scale cycles were identified. Based on the stacking patterns of them, six depositional sequences, six third and two second order cycles were determined. Third order cycles coincide with the Global Sea Level Change Curve. On the account of the conducted petrographic analysis sandstone, mudstone, marl, limestone and muddy-limestone lithofacies were recorded in the studied samples. In order to demostrate the response of foraminifers to cyclicity, quantitative analysis has been carried out by counting the individuals of planktonic, benthonic foraminifers and ostracods. The best response to sedimentary cyclicity was revealed from planktonic foraminifers. The average abundance of planktonic foraminifers increases in the transgressive systems tract and decreases in the highstand systems tract.

The Upper Devonian-Lower Mississippian Bakken Formation has recently become a prolific producer of light gravity oil in southeastern Saskatchewan since the advent of horizontal drilling and multi-stage hydraulic fracture technologies, which has resulted in an increase in geological studies within the area. However, the Bakken Formation of west-central Saskatchewan has been producing heavy oil since the 1950s, and has comparatively received much less attention than its southeastern counterpart. The Bakken Formation is the youngest member of the Three Forks Group and unconformably overlies the Big Valley Formation. In west-central Saskatchewan, the Bakken Formation can be conformably overlain by the Mississippian carbonates of the Madison Group or unconformably overlain by the Lower Cretaceous Mannville Group. A tripartite subdivision is applied to the Bakken Formation, with a mixed clastic/carbonate Middle Member deposited between Lower and Upper Black Shale Members. Based on detailed core description, eight facies have been defined for the Bakken Formation of west-central Saskatchewan: Facies 1 (Lower and Upper Black Shale members), Facies 2 (bioturbated siltstone/sandstone), Facies 3 (wave-rippled sandstone), Facies 4 (bioclastic grainstone), Facies 5 (interbedded mudstone, siltstone, and very fine-grained sandstone), Facies 6 (very fine- to fine-grained sandstone), Facies 7 (bioturbated siltstone/sandstone), and Facies 8 (massive and brecciated siltstone). Deposition of the Bakken Formation in west-central Saskatchewan occurred under either open-marine or marginal-marine conditions. Facies association 1 (open-marine interval), which is made up of F1 through F4, is characterized by the distal Cruziana Ichnofacies. It was deposited within a wave-dominated shallow-marine depositional environment. Facies association 2 (marginal-marine interval), which is comprised of F5 through F8, shows scarce biogenic structures, most likely as a result of brackish-water conditions. Geological mapping (structure surface and isopach) of the facies and facies associations has aided in illustrating their lateral distribution. However, mapping of the overlying Mississippian carbonates and sub-Mesozoic unconformity shows that post-Mississippian erosion was a controlling factor in the distribution and preservation of Bakken Formation deposits, which creates uncertainty when interpreting geological maps and stratigraphic cross-sections. Although post-Mississippian erosion causes problems when reconstructing the depositional history and stratigraphic architecture of the Bakken Formation, it illustrates the importance of not performing stratigraphic studies within a vacuum, only focusing on the formation of interest. Rather, underlying and overlying units must be studied to see whether or not the unit of interest’s deposition and distribution has been affected by pre- and post-depositional events.

Three studies on Cordilleran foreland basin deposits in the western U.S.A. constitute this dissertation. These studies differ in scale, time and discipline. The first two studies include basin analysis, flexural modeling and detailed stratigraphic analysis of Upper Cretaceous depocenters and strata in the western U.S.A. The third study consists of detrital zircon U-Pb analysis (DZ U-Pb) and thermochronology, both zircon (U-Th)/He and apatite fission track (AFT), of Upper Jurassic to Upper Cretaceous foreland-basin conglomerates and sandstones. Five electronic supplementary files are a part of this dissertation and are available online; these include 3 raw data files (Appendix_A_raw_isopach_data.txt, Appendix_C_DZ_Data.xls, Appendix_C_UPb_apatite.xls), 1 oversized stratigraphic cross section (Appendix_B_figure_5.pdf), and 1 figure containing apatite U-Pb concordia plots (Appendix_C_Concordia.pdf). Appendix A. Subsidence in the retroarc foreland of the North American Cordillera in the western U.S.A. has been the focus of a great deal of research, and its transition from a flexural foreland basin, during the Late Jurassic and Early Cretaceous, to a dynamically subsided basin during the Late Cretaceous has been well documented. However, the exact timing of the flexural to dynamic transition is not well constrained, and the mechanism has been consistently debated. In order to address the timing, I produced new isopach maps from ~130 well log data points that cover much of Utah, Colorado, Wyoming and northern New Mexico, producing in the process, the most detailed isopach maps of the area. These isopach maps span the Turonian to mid-Campanian during the Late Cretaceous (~93–76 Ma). In conjunction with the isopach maps I flexurally modeled the Cordilleran foreland basin to identify when flexure can no longer account for the basin geometry and identified the flexural to dynamic transition to have occurred at 81 Ma. In addition, the dynamic subsidence at 81 Ma is compared to the position of the hypothesized Shatsky Oceanic Plateau and other proposed drivers of dynamic subsidence. I concluded that dynamic subsidence is likely caused by convection over the plunging nose of the Shatsky Oceanic Plateau. Appendix B. The second study is a detailed stratigraphic study of the Upper Cretaceous, (Campanian, ~76 Ma) Sego Sandstone Member of the Mesaverde Group in northwestern Colorado, an area where little research has been done on this formation. Its equivalent in the Book Cliffs area in eastern Utah has been rigorously documented and its distal progradation has been contrastingly interpreted as a result of active tectonism and shortening in the Cordilleran orogenic belt ~250 km to the west and to tectonic quiescence, flexural rebound in the thrust belt and reworking of proximal coarse grained deposits. I documented ~17 km of along depositional dip outcrops of the Sego Sandstone Member north of Rangely, Colorado. This documentation includes measured sections, paleocurrent analysis, a stratigraphic cross section, block diagrams outlining the evolution of environments of deposition through time, and paleogeographic maps correlating northwest Colorado with the Book Cliffs, Utah. The sequence stratigraphy of the Sego Sandstone Member in northwest Colorado is similar to that documented in the Book Cliffs area to the south-southwest, sharing three sequence boundaries. However, flood-tidal delta assemblages between fluvio-deltaic deposits that are present north of Rangely, Colorado are absent from the Book Cliffs area. These flood-tidal-delta assemblages are likely caused by a large scale avulsion event in the Rangely area that did not occur or was not preserved in the Book Cliffs area. In regards to tectonic models that explain distal progradation of the 76 Ma Sego Sandstone Member to be caused by tectonic quiescence and flexural rebound in the thrust belt, the first study shows that at 76 Ma, flexural processes were no longer dominant in the Cordilleran foreland, so it is inappropriate to apply models driven by flexure to the Sego Sandstone Member. Dynamic processes dominated the western U.S.A. during the Campanian, and flexural processes were subordinate. Appendix C. In order to test the tectonic vs. anti-tectonic basin-filling models for distal coarse foreland deposits mentioned above, the third study involves estimating lag times of Upper Jurassic to Upper Cretaceous conglomerates and sandstones in the Cordilleran foreland basin. Measuring lag time requires a good understanding of both the stratigraphic age of a deposit and the thermal history of sedimentary basin. To further constrain depositional age, I present twenty-two new detrital zircon U-Pb (DZ U-Pb) sample analyses, spanning Upper Jurassic to Upper Cretaceous stratigraphy in Utah, Colorado, Wyoming and South Dakota. Source exhumation ages can be measured using thermochronology. To identify a thermochronometer that measures source exhumation in the North America Cordillera, both zircon (U-Th)/He, on eleven samples, and apatite fission track (AFT) thermochronology, on eleven samples was performed. Typically, the youngest cooling age population in detrital thermochronologic analyses is considered to be a source exhumation signal; however, whether or not these apatites are exhumed apatites or derived from young magmatic and volcanic sources has been debated. To test this, I double dated the detrital AFT samples, targeting apatites with a young cooling age, using U-Pb thermochronology. Key findings are that the maximum depositional ages using DZ U-Pb match existing biostratigraphic and geochronologic age controls on basin stratigraphy. AFT is an effective thermochronometer for Lower to Upper Cretaceous foreland stratigraphy and indicates that source material was exhumed from >4–5 km depth in the Cordilleran orogenic belt between 118 and 66 Ma, and zircon (U-Th)/He suggests that it was exhumed from <8–9 km depth. Double dating apatites (with AFT and U-Pb) indicate that volcanic contamination is a significant issue; without having UPb dating of the same apatite grains, one cannot exclude the possibility that the youngest detrital AFT population is contaminated with significant amounts of volcanogenic apatite and does not represent source exhumation. AFT lag-times are 0 to 5 Myr with relatively steady-state to slightly increasing exhumation rates. We compare our data to orogenic wedge dynamics and subsidence histories; all data shows active shortening and rapid exhumation throughout the Cretaceous. Our lag-time measurements indicate exhumation rates of ~.9–>>1 km/Myr.

L’intervalle Aptien-Albien inférieur de la marge sud-téthysienne est mal connu en raison de successions souvent incomplètes et de difficultés à les dater. Le Bassin d’Essaouira-Agadir (BEA), au Maroc, présente de nombreuses coupes, bien exposées et accessibles du Crétacé inférieur. Le but de ce travail est de (1) établir un cadre stratigraphique intégré de la série apto-albienne, basé sur (a) la biostratigraphy haute résolution des ammonites et des nannofossiles calcaires, (b) l’identification des discontinuités sédimentaires et (c) la stratigraphy isotopique du carbone; (2) reconstituer l’évolution paléoenvironnementale pendant cet intervalle, par l’étude des facies sédimentaires et l’analyse qualitative et quantitative des nannofossiles, et (3) proposer un modèle de fonctionnement de la plateforme-rampe mixte, carbonate-clastique, du BEA.Dans le BEA, le Barrémien supérieur est défini par la zone d’ammonites à sarasini et par la zone de nannofossiles NC5. La limite Barrémien-Aptien est définie par les ammonites. L’Aptien inférieur est déterminé par les zones d’ammonites à desahayesi jusqu’à furcata, et est limité par un premier minimum de 13C à la base, et par un premier maximum à la limite Aptien inférieur-moyen. L’Aptien supérieur est défini par quatre zones d’ammonites (martini, melchioris, nolani et jacobi), deux surfaces de discontinuité, quatre maxima et minima de 13C, et comprend la partie supérieure de NC6, NC7 et la base de NC8. La limite Aptien-Albien est placée dans la discontinuité D4 (base de la zone d’ammonites à Leymeriella tardefurcata), en accord avec la première occurrence (FO) des nannofossiles Prediscosphaera columnata et Hayesites albiensis, et par une diminution des valeurs de 13C. L’Albien inférieur est daté par les zones d’ammonites à tardefurcata et mammillatum, par la FO du nannofossile Hayesites albiensis, et par des valeurs minimales de 13C.Les faciès et environnements de dépôt des sédiments aptien à Albien inférieur ont été déterminés par leur lithologie, les figures sédimentaires, leur contenu faunique et les microfaciès. Ils ont permis d’identifier (1) quatre types de surface liées à des érosions subaériennes ou sous-marines, (2) quatre faciès sédimentaires carbonatés dans l’Aptien, correspondant à des environnements de rampe interne à distale, et (3) quatre faciès sédimentaires argilo-gréseux dans l’Albien inférieur, représentant des dépôts de rampe médiane à hémipélagiques. Ces faciès reflètent des milieux adjacents et passant de l’un à l’autre. L’intervalle Aptien-Albien inférieur du BEA a été subdivisé en deux cycles, soulignés par deux surfaces d’érosion majeures. Le cycle Barrémien terminal-Aptien est souligné par une surface karstifiée et erosive et comprend quatre séquences de dépôt de troisème ordre. Le cycle Albien surmonte une surface majeure d’érosion sous-marine, et contient au moins quatre sequences de dépôt. Dasns chaque cycle, l’évolution vertical des faciès indique un approfondissement ds milieux de depot liée à une hausse eustatique.Dans le BEA, production carbonatée est plus élevée à l’Aptien qu’à l’Albien inférieur, en raison d’un climat chaud, une lente montée du niveau de la mer, un milieu de dépôt peu profond et de faibles apports détritiques. L’abondance totale absolue des nannofossiles décroît entre l’Aptien et l’Albien inférieur, en raison d’un taux de sedimentation plus élevé associé à une subsidence plus rapide. L’apport en nutriments, la fertilité et la production primaire sont plus élevés à l’Albien inférieur qu’à l’Aptien, et sont principalement contrôlés par la montée du niceau de la mer et les courants d’upwellings. La transition Aptien terminal-Albien inférieur est marquée par l’abondance de taxons d’eau froide et par la migration de faunes cosmopolitaines du domaine boréal vers le domaine téthysien, qui pourrait traduire un événement climatique froid, voire glaciaire. / The Aptian-Early Albian interval of the southern Tethyan margin is poorly understood since sedimentary successions are frequently incomplete and dating is difficult. The Essaouira-Agadir Basin (EAB), Morocco, presents numerous, very good and accessible outcrops of the Early Cretaceous series. The aim of this work is to (1) establish an integrated stratigraphic framework of the Aptian-Albian series based on (a) high-resolution ammonites and calcareous nannofossil biostratigraphy, (b) identification of sedimentary discontinuities and (c) carbon isotope stratigraphy; (2) reconstruct the paleoenvironmental evolution during this interval through both sedimentary facies evolution and qualitative and quantitative nannofossil analyses, and (3) propose a functioning model for the sedimentation on the mixed, carbonate/clastic ramp of the EAB.In the EAB, the Late Barremian is defined by the sarasini ammonite zone and the NC5 nannofossil zone. The Barremian/Aptian boundary is defined by ammonites. The Early Aptian is defined by the deshayesi to furcata ammonite zones, and is bounded by a first minimum 13C value at the base and a first maximum value at the Early/Late Aptian Boundary. The Late Aptian interval, is defined by four ammonite zones (martini, melchioris, nolani and jacobi), two discontinuity surfaces, four maximum and minimum 13C values, and by the upper part of the NC6, the NC7 and the lowermost part of the NC8 nannofossil zones. The Aptian/Albian boundary is placed within the discontinuity D4 (base of the Leymeriella tardefurcata ammonite zone), supported by the First Occurrence (FO) of the Prediscosphaera columnata and Hayesites albiensis nannofossil taxa, and by decreasing 13C values. Early Albian times are represented by the tardefurcata and mammillatum ammonite zones, the FO of Hayesites albiensis, and by minimum 13C values.The facies and depositional environments of the Aptian-Early Albian rocks are identified based on their lithology, sedimentary structures, fossil content and microfacies. These allowed to identify (1) four types of key surfaces related subaerial or submarine erosion, (2) four sedimentary carbonated facies in the Aptian corresponding to outer to inner ramp depositional environments, and (3) four Early Albian sedimentary facies, represented by sandstones and shales, of basin to middle ramp depositional setting. These facies reflect deposition in adjacent and gradational paleoenvironments. The Aptian-Early Albian stratigraphic interval of the EAB, has been subdivided into two major cycles, floored by two major erosional surfaces. The latest Barremian-Aptian cycle is underlined by a major karstified-erosional surface and consists of four third-order depositional sequences. The Early Albian cycle, overlies a major submarine erosional surface, and also contains four depositional sequences. In each cycle, the vertical changes in facies indicates a deepening upward trend related to sea level rise.The carbonate production in the EAB is higher in the Aptian than during the Early Albian, due to warm conditions, slow rise of sea level, shallow depth of the basin, and little detrital influx. The nannofossil total absolute abundance decreases from the Aptian to the Early Albian, due to increasing sedimentation rate, associated with rapid subsidence. The nutrient input, fertility and calcareous nannofossil primary productivity is higher in the Early Albian with respect to the Aptian, and are mainly controlled by rising sea level and upwelling currents. The Latest Aptian-Early Albian period is characterized by a high abundance of cold taxa, and the migration of cosmopolitan biota from Boreal realm into the Tethyan realm, which may reflect the occurrence of a glacial climatic event.