The Cretaceous Almond Formation, located in the Greater Green River Basin, records deposition of coastal plain fluvial sandstones and shallow marginal-marine sandstones in a net-transgressive sequence along the western margin of the Cretaceous Interior Seaway (CIS) from the late Campanian to early Maastrichtian. The Almond Formation is an important hydrocarbon reservoir, with development mainly along the Wamsutter Arch and the northeast margins of the Washakie Basin. Previous studies have primarily focused on outcrops along the eastern flank of the Rock Springs Uplift and subsurface data targeting the Wamsutter Arch. Further development of the Almond petroleum system requires extending our understanding of lateral facies changes and sequence stratigraphic architecture away from areas that have been previously studied. The aim of this research is to build a predictive model of lateral and temporal facies transitions and associated reservoir character along the Cherokee Arch in southern Wyoming. This structural feature marks the southern margin of the Washakie Basin and is roughly perpendicular to the shoreline of the CIS. Outcrop examination at either end of the arch shows that lower Almond strata along the western margin of the Washakie Basin transition from coastal plain facies associations to time-equivalent shallow-marine strata to the east, while the upper Almond strata transition from shallow-marine sands to offshore and prodeltaic muds across the ~125 km separating the two outcrop localities. This reveals clear facies associations shifts at the basin scale, which are difficult to interpret using only well data. The preservation of shoreface strata and related near-shore, fluvio-deltaics across large distances in the dip direction shows the large magnitude of shoreline migration. This also suggests that the system gradient was likely very gentle, leading to wide facies belts, and that reservoir continuity could be complex over significant distances. Stacking patterns observed in outcrop, core, and log curves demonstrate an early progradational sequence across the basin from the west to east. This time equivalent strata suggests sediment supply outpaced accommodation during deposition of the lower Almond and equivalent basinward strata, leading to progradation and eventually to some aggradation before relative sea-level rose. This is significant as the Almond is thought primarily as an overall retrogradational system. Within the upper Almond and basinward equivalent strata, stacking patterns reveal a well preserved retrogradational sequence as accommodation outpaced sediment supply during the final transgression of the Mesaverde Group. Core and outcrop analysis to the east at this time show facies associations that potentially represent an inundated, estuarine deltaic environment of deposition transitioning to deltaic depofacies to the west. Clinoformal geometry and an additional sand found in the subsurface of a cluster of only southern wells corroborate a deltaic interpretation. This sand is interpreted as a lobate deposit flanked by shale to the north. Shorelines span a short distance in the east and a much broader distance to the west with a clear facies shift in between allowing for marine shale to directly overlay coastal plain facies. Outcrop, core, and subsurface datasets have led to a better understanding of sediment partitioning and preservation during this transgressive phase of the CIS in the western United States. A better understanding of these spatial and temporal patterns will help to remove risk associated with exploration along this trend, as well as serve as an analogue for other transgressive deposits. Additional data would increase knowledge of this system and lead to solidification of new ideas presented for the Almond Formation along the Cherokee Arch.

Le Début Glaciaire peut être conservé à la faveur d’une protection par les loess postérieurs et la progradation des versants. Les dépôts de fonds de vallée antérieurs aux Weichselien sont rencontrés sous trois formes : (a) des nappes graveleuses accumulées en piedmont du haut-pays, (b) des dépôts eemiens isolés et à faible profondeur (c) des dépôts fluviatiles du Saalien et de l’Eemien à une vingtaine de mètres de profondeur dans la plaine de la Lys et dans la partie aval de la Deûle et de la Marque. Il s’agit alors du comblement de la «vallée flamande». La chronostratigraphie et les variations des pentes longitudinales du bed rock suggèrent une morphogenèse récente (depuis le Saalien). Une attention particulière a été portée aux enregistrements pléniglaciaires d’activités fluviatiles sur versant et dans les extrémités amont du réseau de talwegs. Les périodes du Pléniglaciaire inférieur et moyen weichseliens sont mal documentées. Des indices indirects suggèrent une forte activité fluviatile pendant le Pléniglaciaire inférieur. Quelques formations limoneuses enfouies dans les plaines sont attribuées au Pléniglaciaire Moyen. La base du Pléniglaciaire supérieur est érosive. La période se divise en : (a) une phase d’activité fluviatile intense, (b) à partir d’environ 22 ka, une forte rétractation du réseau hydrographique actif et un remblaiement fluvio-éolien massif. Un modèle d’évolution de petite vallée en zone loessique à la fin du Pléniglaciaire supérieur weichselien est proposé. Le Tardiglaciaire est principalement connu à travers les enregistrements complémentaires d’Houplin-Ancoisne et de Dourges. / Early Glacial layers can be preserved in favor of protection of the subsequent loess and progradation of slopes. The valley bottoms deposits anterior to the Weichselian can be of three different natures: (a) accumulations of gravel layers at the foot of hight country, (b) shallow isolated Eemian deposits, (c) Saalian and Eemian fluvial layer about twenty meters deep in the Leie river plain or in downstream section of the Deûle and Marque rivers. In this case, they fill the “Flemish valley”. The chronostratigraphy and changes of longitudinal bed rock slopes suggest a recent morphogenesis (since Saalian) propbablu related to the paleogeographic evolution of the North sea basin. Particular attention has been paid to records of fluvial activity on slopes and in the upstream extremities of the talwegs network. The lower and middle pleniglacial weichseliens are poorly documented. Indirect evidences suggest a strong fluvial activity during the Lower Pleniglacial. Some buried silt formations are attributed to the Middle Pleniglacial, without certainty. The lower limit of the Upper Pleniglacial is erosive. The Upper Pleniglacial is divided into: (a) a phase of intense fluvial activity, (b) from about 22 ka, a severe shrink of the active hydrographic network and a massive fluvio-aeolian filling. We propose a modele for the morphosedimentary evolution of a small valley in loess area context during the Weichselian Upper Pleniglacial. Lateglacial is mainly known through the complementary records of Houplin-Ancoisne and of Dourges.

Bedrock islands add variation to the estuarine system that results in deviations from typical unconfined estuarine sediment transport patterns. Limited literature exists regarding the dynamics of seabed morphology, delta formation, sediment divergence patterns, and sedimentary facies classifications of non-fjordic bedrock confined systems. Such knowledge is critical to address coastal management concerns adequately. This research presents insights from the Skeena Estuary, a macrotidal estuary in northwestern Canada with a high fluvial sediment input (21.2-25.5 Mtyr-1). Descriptions on sub-environments, stratification, and sediment accumulation within the Skeena Estuary utilize HydroTrend model outputs of riverine sediment and discharge, Natural Resources Canada radiocarbon-dated sediment cores and grain size samples, and acoustic Doppler current profiler and conductivity-temperature-depth measurements from three field campaigns. Research findings delineate a fragmented delta structure with elongated mudflats and select areas of slope instability. Variations from well-mixed water circulation to lateral stratification, govern the slack tide flow transition and sediment transport pathways within seaward and landward passages of the estuary. Fostering a comprehensive understanding of bedrock confined estuary and delta systems has implications for the assessment of coastal management strategies, the productivity of ecological habitats, and the impacts of climate change within coastal areas. / Graduate