Date of Award
Master of Science (MS)
The Lower Cretaceous Newcastle Formation of the Black Hills has been traced, through the use of well logs, from near the type section in eastern Wyoming into the subsurface of the Williston Basin. In the Basin, the Newcastle Formation is a very fine to medium grained, gray to white, quartzose sandstone, which overlies the Skull Creek Shale and underlies the Mowry Shale. In area where the Newcastle is absent the overlying and underlying shales cannot be separated and here are referred to as “undifferentiated Mowry-Skull Creek”.
Newcastle deposition occurred mainly in the eastern one-third and western quarter of North Dakota. Correlation of these sandstones is possible through northern South Dakota and along a 100-mile by 25-mile wide belt of siltstones and very fine grained sandstone through south-central North Dakota.
The Newcastle is probably largely marine sandstone that was deposited in a near-shore environment. In eastern North Dakota, it occurs as a blanket sandstone which thickens toward the east where is it overlain unconformably by Tertiary and Pleistocene deposits. A large thickened area of Newcastle in southeastern North Dakota suggests a possible delta complex. Newcastle thicknesses in western North Dakota are variable and deposition was controlled by offshore currents.
Possible oil producing stratigraphic traps in the Newcastle may occur along normal depositional limits in the western part of the Williston Basin where the sandstone occurs downdip, or in sandstone pinchouts against or along structures along the east side of the basin.
Reishus, Mark, "The Newcastle formation in the Williston Basin of North Dakota" (1967). Theses and Dissertations. 241.