| Analysis and interpretation of geological and geophysical data available for the central Bighorn Basin suggest the presence of an E-W-trending wrench fault zone in the vicinity of Tatman Mountain, referred to as the Fenton Pass Fault Zone (FPFZ). A NW-trending seismic profile, oriented at a high angle to the wrench fault, displays a positive flower structure with a series upward and outward branching faults connected to a zone of sub-vertical faults which appear to offset Precambrian basement along a zone approximately 6.4 to 8 km (4-5 miles) wide. The zone of basement wrench fault offset appears to be located beneath and parallel to the four E-W-trending Pleistocene terraces of Tatman Mountain. These observations correlate with the E-W-trending anomalies interpreted from residual aeromagnetic data acquired for the central basin area. A series of NE-trending faults initially field mapped in this area appears to be genetically related to the existence of the E-W-trending wrench fault zone. Additional mapping over a wider area, using Landsat Thematic Mapper imagery, indicates a pattern of interconnected surface faults which resemble the geometry of R, R... |
