Geochemical data for geothermal exploration on Grao Sakti, Jambi, Indonesia

Abstract

Sumatra has more than 20 geothermal areas the associated with Sumatra Fault System and volcanic system along Barisan Range. Grao Sakti is a geothermal area in Renah Kemumu, Jangkat District, Merangin Regency, Jambi, such a characteristic. Geochemical data is a part of early geothermal exploration for identification fluid type, estimating temperature geothermal reservoir, and assessment geothermal system. We used two geothermal fluids manifestation sample for geochemical analyzed. These three methods for determining fluids geothermal characteristic, including of geothermal fluids type, geothermal of partial chemical equilibrium, and solute geotermometers. Geothermal manifestation is consist of geyser and hot spring with temperature about 66.8°C - 91.5°C. The result analysis Cl-SO4−HCO3 to show chloride fluid type, as indicated of fluid geothermal reservoir. Geothermal fluid of Na-K-Mg on partial chemical equilibrium as clue geothermal fluids of boiling condition. Solute geotermometers used to approach silica geotermometer about 146.50°C - 172.24°C, while solute sodium-potassium geothermometer about 203.19°C - 206.18°C. Geothermal fluids of geochemical analysis as hint geothermal reservoir temperature and the geothermal reservoir was classified medium temperature, which is potential for geothermal energy resource and electricity with binary system. The review of geological setting, this area is classified as a volcano-tectonic geothermal system with liquid dominated reservoir.