NEW KINEMATIC MODEL OF THE SOUTHERN UTAH VIRGIN ANTICLINE THROUGH NEW 3-D STEREOSCOPIC AND TRADITIONAL FIELD METHODS

Detailed analysis of the Quail Creek Reservoir and Little Purgatory Dome along the Virgin Anticline in southern Utah reveals evidence for a new structural kinematic model of the region. New 3D mapping software, used in concert with field work methodology and observations, makes it possible to create maps with a higher degree of accuracy in a shorter period of time.

The Virgin Anticline area was analyzed using Cardinal Systems 3-D remote sensing stereoscopic software as well as traditional field methods. Thrust faulting has been observed on either side of the anticline through the repetition of bedding, thickened members of the Chinle formation, nonlinear contacts, asymmetrical drainage patterns, visual displacement, the morphology of known thrust faulting, and the presence of back thrusts. A 1:24,000 scale map comprising Quail Creek Reservoir and the Little Purgatory Dome shows the overall structure of the anticline, while a larger scale map at 1:12,000 shows the detailed northern edge of the Little Purgatory Dome. These maps show how thrust faulting associated with anticlinal formation along this particular portion of the Virgin Anticline helps to accommodate contractional strain likely related to the Sevier Orogeny.