Gravity Study of the Fumarole Butte Area, Juab and Millard Counties, Utah

A gravity survey was made in 1973 of the Fumarole Butte area, including the Crater Springs KGRA (Baker Hot Springs), located approximately 39 km (22 miles) NW of Delta, Utah. About 500 stations were taken as part of a study of geothermal exploration techniques. The region of investigation includes portions of both Juab and Millard Counties and incorporates parts of the Desert, McDowell and Drum Mountains. A simple Bouguer gravity anomaly map was computed and two-dimensional geologic models were prepared for two east-west gravity profiles. The analysis of the gravity data, in conjunction with the known geology and the results from other geophysical studies, led to the following interpretations: 1) the indication of two buried intrusive bodies - one a north north westward-trending dike lying beneath the Baker Hot Springs and the eastern margin of the Fumarole Butte lava flows and another several miles southwest of Desert Mountain; 2) the delineation of previously ' unpublished Basin and Range faults and associated grabens; and 3) the existence of a basement flexure with postulated fractures that served as conduits for the upwelling magma to reach the surface at Fumarole Butte.