ABSTRACT

Linear features have been observed on enhanced Landsat images in an area of more than 130,000 km2 near the northern Black Hills. The study area includes the southeastern part of the Williston Basin (Montana, North Dakota and South Dakota) and the northwestern part of the Powder River Basin (Wyoming). Lineaments are interpreted as areas in which short linear features less than 8 km long are concentrated; the areas are bounded by individual linear features greater than 32 km long. Lineaments are domains of linear features observed on satellite images.

The geological significance of Landsat features is established by comparing maps of linear features and lineaments with other types of geologic data. Linear features correspond to monoclines in the vicinity of the Black Hills and to specific structures interpreted from seismic records. Landsat lineaments correspond to variations in joint sets and to lineaments interpreted from aerial photographs and stratigraphic data. Landsat lineaments are believed to reflect fault zones bounding structural blocks in the Precambrian basement and linear features representing constituent faults within the zones.