WILLIS, GRANT C., MICHAEL L. ROSS, and HELLMUT H. DOELLING, Utah Geological Survey, Salt Lake City, UT

ABSTRACT: Results of Detailed Mapping in the Northern Paradox Basin and Southeastern Uinta Basin Energy and Metal Resource Area, Grand and Uintah Counties, Utah

The Utah Geological Survey is conducting a concentrated, 1:24,000-scale geologic mapping program in the northern Paradox and southeastern Uinta basins of east-central Utah. The region is an important producer of energy and metal resources and exploration interest remains high. Eleven 7.5-min quadrangle geologic maps (650 sq mi) have been mapped and five more quadrangles are in progress. Major mapped features include the North Mountain laccolithic center of the LaSal Mountains; dissolution-collapsed, salt-cored anticlines in Moab-Spanish, Cache, Castle, and Fisher Valleys; crystalline basement-sedimentary cover relationships in the Westwater Canyon area; parts of the Sego coal field in the southern Book Cliffs; parts of the Bartlett Flat (Kanes Springs unit), Greater Cisco, Bryson Cany n, Westwater, Fence Canyon, and Middle Canyon oil and gas fields, and the PR Springs bituminous sandstone (tar sand) area.

Major contributions include new constraints on the intrusive history of the laccoliths; refined correlations of subsurface and surface units; more detailed documentation of folding, faulting, and structural and stratigraphic thinning and thickening (some related to salt diapirism or dissolution); improved correlation of coal seams and bituminous sandstone beds; new dating and correlation of Quaternary deposits; and new constraints on the Quaternary history of this part of the Colorado Plateau.

AAPG Search and Discovery Article #90993©1993 AAPG Rocky Mountain Section Meeting, Salt Lake City, Utah, September 12-15, 1993.