| Abstract |
Kampar-Kuantan Singingi, Riau Province and Tanjung Jabung TImur, Jambi Province, Sumatera are ones of non volcanic geothermal areas at back arc basin, in central Sumatera basin (Riau) and South Sumatera Basin (Jambi), Indonesia. The geothermal manifestations are only hot springs (Kepanasan, Gunung Sahilan, Sungai Pinang, Pandan Sejahtera, and Bandar Jaya). The temperatures are about 46.8-64.5oC with neutral pH. In general the structure of the area followed the pattern of regional structure of Sumatera island trending northwest-southeast and the lithology of the area dominated of sedimentary rocks and alluvial. All of them are bicarbonate type and immature waters but only Kepanasan hot springs reached partially equilibrium. The temperature of geothermal reservoir is about 138oC (Kepanasan), 90oC (Gunung Sahilan), 83oC (Sungai Pinang), and . 100oC (Geragai), These areas are classified into low to medium temperature. |