Lineament Analysis Based on Landsat Imagery, Texas Panhandle

Analysis of seven frames of Landsat imagery covering the Texas Panhandle and adjacent areas revealed linear physiographic features including stream channels, stream valleys, scarps, and aligned playa-lake depressions. These lineaments show preferred orientations of 300°-320°, 030°-050°, and, 0°-020°. The 300°-320° orientation of aligned playas and shallow surface drainage is best developed on the surface of the Southern High Plains. The orthogonal 030°-050° orientation is less well represented. Lineaments oriented 0°-020° are most readily detected in the dissected terrain of the Roiling Plains in the eastern Texas Panhandle; a secondary orthogonal trend oriented 270°-280° is also present. Lineament orientations are similar to orientations of joints measured in the field and to regional structural trends, which suggests that development of physiographic lineaments is controlled or influenced by geologic structure. Few surface faults are mapped in the region; therefore, joints rather than widespread faults are a likely structural geologic control, Joints may provide paths of weakness along which surface drainage might develop preferentially. Joint intersections provide potential sites for downward percolation of water, possibly enhancing playa development, as suggested by dissolution of caliche beneath playas. Thus, joints probably exert an important control on the geomorphology of the region.