Integrated facies analysis and stratigraphic architecture of Cretaceous McMurray Formation and Wabiskaw Member of the Clearwater Formation, Ells River Paleovalley, NE Alberta, Canada

The McMurray Formation and Wabiskaw Member of the Clearwater Formation within the Ells River Paleovalley of the Athabasca Oil Sands Region represent a geologic study on marginal marine to shallow marine strata, and in the context of the Wabiskaw Member, an economic resource. This thesis provides a concise overview of the facies associations and stratigraphy of these units. The McMurray Formation, primarily of middle to late Aptian age, consists predominantly of unconsolidated to weakly consolidated sands, silts, and clays, which were deposited in a fluvial-deltaic setting. These deposits are strikingly heterogenous due to the interplay of sedimentary processes during their deposition. The stratigraphy of the McMurray Formation in the Ells River Paleovalley is characterized by lateral variations in facies, with fluvial channel sands, floodplain silts and clays, and estuarine muds forming a complex mosaic. These sediments were deposited in response to changing environmental conditions during the Aptian Period, including fluctuations in sea level and shifts in fluvial dynamics. Consequently, the distribution of bitumen-bearing sands within the formation is intricately tied to paleoenvironmental variations. The Albian-aged Wabiskaw Member of the Clearwater Formation stands out as a distinctive stratigraphic unit within the Ells River Paleovalley. It typically consists of laterally extensive fine to medium-grained sands with muddy silt interbeds. The Wabiskaw Member is recognized for its relatively high bitumen content and has been the focus of extensive hydrocarbon exploration and production activities in the study area. Understanding the facies and stratigraphy of the McMurray Formation and Wabiskaw Member is crucial for refined paleoenvironmental interpretations, as it informs exploration and production strategies. Additionally, this knowledge has broader implications for paleogeographic reconstructions and our understanding of ancient fluvial, embayment, and shoreface-deltaic systems. Future research in this region will continue to refine our understanding of these formations, aiding in sustainable resource management and environmental preservation.