From abstract: This report describes Cambrian through Mississippian rocks in the Powder River Basin representing five depositional sequences that reflect both the biological evolution and the tectonic development of western North America.
From introduction This report describes large-scale depositional units referred to as architectural elements, interpreted from outcrops of three distinct fluvial sandstone units of the Lakota Formation in the southwestern Black Hills area of Custer and Fall River Counties, South Dakota. These fluvial deposits formed near the end of an episode of continental deposition that began when the Jurassic Sundance sea regressed from the region and ended when the Early Cretaceous Skull Creek sea encroached from the north in Albian time.
From abstract: This report contains complete Bouguer anomaly, isostatic residual anomaly, and horizontal gradient anomaly gravity maps of the Powder River Basin and surrounding areas in southeastern Montana, northeastern Wyoming, and western South Dakota were compiled using gravity data from 21,528 stations. A total-intensity anomaly aeromagnetic map with 3 mile spaced east-west flight-lines is also presented. Also included is an analysis of these maps and data, focusing on gravity and aeromagnetic studies.
From abstract: The uppermost Cretaceous Lance Formation was studied in the Powder River Basin and nearby basins of Wyoming and Montana. The Lance Formation is overlain by the continental Paleocene Fort Union Formation. This report is a petrography and stratigraphy study on these basins.
From abstract: This report is a study on the history of sedimentology and deposition of the lower Paleocene Tullock Member of the Fort Union Formation, Powder River Basin, Wyoming and Montana while looking at the geometry and sedimentary structures.
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