The Amarillo-Wichita Uplift and related structures of the Texas Panhandle and southern Oklahoma are characterized by significant vertical basement offsets. However, stratigraphic and structural evidence indicate that this vertical offset formed in response to even larger lateral offsets.

Stratigraphic evidence of strike-slip deformation includes the juxtaposition of dissimilar basement terranes and inconsistent facies and isopach trends in pre-Pennsylvanian strata across the uplifts. Structural evidence includes en echelon folds and faults, simultaneous development of both extensional and compressional tectonics within the same structural belt, and abrupt vertical changes along faults.

Strike-slip faulting along the axis of the former or Southern Oklahoma Aulacogen formed during the Pennsylvanian. Erosional edges of older units, which sub-crop beneath the Mississippian, provide "piercing points" which

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demonstrate offset of 120 km in a left-lateral sense along the axis of the Amarillo-Wichita uplift, Pre-Mississippian units located in the Hardeman Basin of southwestern Oklahoma originally aligned with those in the western Anadarko Basin of the Texas Panhandle. Restoration to the pre-faulting configuration also realigns offset Precambrian basement terranes. Although there has been recurrent deformation along the structural trend since the Precambrian, the orientation of strike-slip and reverse faults and related folds indicate northeast-southwest directed compression during the Pennsylvanian.

* (Study conducted at University of Texas, Bureau of Economic Geology under contract to the U.S. Department of Energy)

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