ABSTRACT
Close-order gravity and magnetic surveys were conducted to locate concealed faults in Mapleton, Utah County, Utah, a developing city along the Wasatch Front, eighty kilometers south of Salt Lake City, Utah. Regional trends were calculated using trend analysis, and residual data were modeled using self-consistent iterative modeling. Ambiguities in the subsurface models were reduced by (1)incorporating data from previous geophysical surveys, surface mapping, and well data; (2)integrating the gravity and magnetic data; and (3)correlating the modeled cross sections. The modeled profiles and integrated 3-D interpretation indicate that there are four major fault blocks beneath the Mapleton area. These faults are potential earthquake threats, especially for possible surface rupture.
