Date of Award
Master of Science (MS)
The Newcastle Formation (Albian) in North Dakota is composed primarily of fine grained sandstone, mudstone and shale. This study examined the Newcastle within the eastern two thirds of North Dakota, with the goal of determining the various depositional environments, the depositional history, and the hydrocarbon potential of the unit. A total of 2191 geophysical well logs and 21 lithologic cores were examined. Isopach maps of the Newcastle Formation and the Skull Creek Shale were generated, as was a structural top map of the Mowry Shale.
The depositional history of the unit is directly linked to the regression and subsequent transgression of the Cretaceous Interior Seaway during the mid to late Albian. The regression of the Skull Creek Seaway exposed the underlying shales to erosion, thereby allowing incision of at least one major drainage system, and possibly several smaller tributary systems in the western part of North Dakota. Sand was eroded from one or more sources, including the Dakota Sandstone, Sioux Quartzite, and Precambrian Shield, all exposed in eastern South Dakota or western Minnesota. These elastics were transported to western North Dakota and eastern Montana, and were deposited as nearshore bars and deltas, as well as channel fill.
Following a brieflowstand, the sea again transgressed over the study area, redistributing the sediments as thin sheet sandstones. Once a new highstand position was established, nearshore and deltaic sediments accumulated along the eastern and southeastern borders of the state. These were often capped by fluvial deposits.
Again the sea transgressed, inundating the recently deposited Newcastle sediments. Deeper, quieter water conditions allowed for the deposition of the Mowry Shale on top of the Newcastle Formation.
Estimates of the hydrocarbon potential of the Newcastle Formation with Time Temperature Indices (TTI) calculations indicate that the unit is not thermally mature enough to produce hydrocarbons within the study area.
McCloskey, Gerald G., "Depositional history, environments of deposition, and hydrocarbon potential of the Newcastle Formation (Lower Cretaceous) of eastern North Dakota" (1995). Theses and Dissertations. 194.