Structural interpretations based on ERTS-1 imagery, Bighorn Region, Wyoming-Montana

Structural analysis is being carried out on bands MSS 5 and 7 of scene 1085-17294. Geologic strucutre is primarily revealed in the topographic relief and drainage. Topographic linears are particularly well developed in the bighorn uplift. Many of these occur along known faults and shear zones in the Precambrian core; several have not been previously mapped. These linears, however, do not continue into the younger rocks of the flanks or do so in a much less marked manner than in the core. Linears are far less abundant in the basin or are manifested only in very subtle tonal contrasts and somewhat straight drainage segments. Some of the linears are aligned along trends previously postulated on the basis of surface mapping to be lineaments. The imagery reveals little or no evidence of strike-slip displacements along these lineaments.