Effects of Subsurface Topography and Hydrogeology on Gunung Talang Hot Water Systems, Sumatra, Indonesia: an Analysis Based on Gravity Data

Abstract

Administratively Gunung Talang geothermal field lies in Solok Regency- West Sumatra Province. Low gravity anomaly (bouguer and residual) occured around Cupak and Gabuo hot water complexes, whilst high gravity anomaly (bouguer and residual) are found in the south SW of the survey area (around Mt. Talang) and is considered as the heat source of the geothermal system in the area. The gravity anomaly leneament trending NW-SE coincident with regional trend of Sumatra Fault. A-B and C-D x-sextion show concave-like shape and getting deeper to the north, this condition reflect the hydrogeology in the area flow from the south to the north and caused the dillution of hot water in the north (normal pH), whilst to the south the hot water has acid type (acid pH).