Abstract: Landsat Expression of Lithosphere Block Margins in the Southern Williston Basin, USA
SHURR, GEORGE W., St. Cloud State University
Landsat images in southwestern North Dakota and eastern Montana show long linear features concentrated in two lineament zones that are interpreted to be the margins of major structural blocks of continental lithosphere. The linear features correspond with linear stream segments, elongate and aligned buttes, and drainage divides. Regional subsurface patterns of lithofacies and thickness suggest that these block margins have experienced paleotectonic activity and large oil fields are located within both lineament zones. The northwest-trending Cedar Creek Anticline is found along one lineament zone; it has had a long history of oil and gas production. A northeast-trending lineament cuts the southern end of the anticline and it includes the horizontal Red River play in Bowman County, ND, and the Lodgepool fields in Stark County, ND.
Landsat images, high altitude photos, and topographic quadrangles are used to map the northeast lineament zone. It is about 15 mi (24 km) wide and extends along strike for more than 150 mi (240 km). Populations of linear features within the border areas of the lineament zone are different than those within the interior or those on lithosphere blocks outside the zone. Geologic structures found in outcrops at four widely-spaced localities along the lineament zone demonstrate that Laramide deformation falls into three separate domains. At the intersection of the northeast lineament zone and Cedar Creek Anticline, there was compression; to the southwest into Montana there was right-lateral displacement; to the northeast into North Dakota there was left-lateral displacement with a significant component of extension.
AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah