Dipole-dipole resistivity delineation of the near-surface zone at the Roosevelt Hot Springs KGRA. Technical report. Volume 76-1

Abstract

Recent dipole-dipole resistivity surveys using 100 m and 300 m dipoles at Roosevelt Hot Springs KGRA, near Milford, Utah have suggested that the north-south length of the convective hydrothermal system may be as great as 20 km. Tertiary granite of the Mineral Mountain pluton seems to be intensely fractured along a narrow (500 m.) sinuous zone trending north and coinciding in part with the Dome Fault. This north-south fracture zone is crosscut by numerous east-west and some northwest-southeast faults. The brine in the fractures and alternation of feldspars to clay both result in lowered resistivities. Leakage of brine westward from the Dome Fault fracture zone is still a realistic interpretation of low resistivity values several kilometers west of the Dome Fault.