Print this pageABSTRACT: Gravity Studies in Southwestern Wyoming: Evidence for a Buried East-West-Trending Uplift North of Rock Springs
Viki Bankey, E. A. Merewether
Recent gravity mapping of southwestern Wyoming has delineated an east-west-trending, 10- to 20 milliGal positive gravity anomaly north of, and perpendicular to, the Rock Springs uplift. This 170 km long anomaly separates negative anomalies associated with the Great Divide and Washakie basins east of Rock Springs and bifurcates the Green River basin west of Rock Springs. It nearly parallels the southeastern part of the Wind River Range uplift and the western part of the Granite Mountains uplift and parallels the Uinta Mountains uplift and the Cherokee Ridge arch.
The positive gravity anomaly is thought to indicate a buried uplift involving the Precambrian basement. Similarities in trends of other foreland structures, as well as its spatial relationship to the Moxa arch and Rock Springs uplift, suggest that this feature is related to westtrending Precambrian structures that were reactivated and formed structural highs in the Late Cretaceous and Tertiary. The structure causing the gravity anomaly was probably forming in the Eocene and Oligocene. Formations overlying this buried uplift are known producers of oil and gas elsewhere in this region. Further studies may deem this a favorable structure for petroleum exploration.
AAPG Search and Discovery Article #91002©1990 AAPG Rocky Mountain Section Meeting, Denver, Colorado, September 16-19, 1990