Detrital Quartz Provenance of the Turner Sandstone

Geology can provide solutions to energy security and climate change issues by promoting informed practices within the fossil fuel industry, supporting efficient extraction strategies that minimize overall environmental impact. Efficient drilling techniques begin with a thorough understanding of the reservoir, which can be characterized through various methods, including provenance analysis to identify the sediment origins and depositional environments. Interpreting sediment provenance is crucial for refining paleogeography and revealing Earth’s past environments, climates, and tectonics. My research focuses on reconstructing the provenance and paleogeography of the Late Cretaceous Turner Sandstone, a significant hydrocarbon reservoir in the Powder River Basin (PRB), WY. The hypothesis is that the Black Hills, located along the eastern margin of the PRB, particularly the earlier Cretaceous Newcastle Sandstone, served as the sediment source for the Turner Sandstone. To test this, samples were collected from outcrops in the Black Hills for petrographic analysis. I utilized a Panochromatic Cathodoluminescence detector attached to a Scanning Electron Microscope and conducted traditional point counting to identify grain composition. Additionally, quartz-typing techniques were used to distinguish three distinct groups of quartz, each linked to different source areas around the Black Hills. My research findings show a strong correlation between Turner and Newcastle composition and quartz type, indicating that the Black Hills were at a structural high during the deposition of the Turner Sandstone(~93.9-89.8 ma). This suggests that the PRB sediments originated from the east, challenging the current view that sediment transport during this period was from the west.