ABSTRACT: Landsat Expression of Laramide Deformation in the Williston Basin, Southwestern North Dakota

SHURR, GEORGE W., St. Cloud State University, St. Cloud, MN

Linear features visible on Landsat images document Laramide deformation in the intracratonic Williston basin. Black and white, multispectral scanner images in bands 5 and 7 and at a scale of 1:1,000,000 have been employed to map linear features in Dunn, Stark, Billings, and Golden Valley Counties in southwestern North Dakota. Dominant modes are northwest and northeast with minor numbers of linear features also trending north-south and east-west. Linear features are concentrated in corridors trending northwest and northeast; these lineament zones have greater tectonic significance than individual linear features.

Subsurface stratigraphic data are essential in assessing the importance of lineament zones. Cretaceous thickness and facies patterns document paleostructures and structure contours show postdepositional features trending parallel to and oblique with lineament zones.

Observations in exposures conform with structural patterns in subsurface and Landsat data. Joint measurements in Tertiary sandstones along the Little Missouri River show the same modes as Landsat linear features. A large Tertiary outlier in Stark County is located along the axis of a syncline that corresponds with a northwest-trending lineament zone.

Integration of Landsat linear features with subsurface and surface observations demonstrates that lineament zones are localized zones of deformation that separate larger blocks with relatively minor deformation. Dip slip on basement faults would produce structures parallel to lineament zones and strike-slip displacement components would produce oblique structures. The style is a hallmark of tectonism in continental lithosphere, and block movements are probably controlled by movement of the North American plate.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)