Tectonic and Structural Setting of Geothermal System in Southern Thailand

Abstract

The tectonic and structural setting in Southern Thailand dominated by the strike-slip systems of the Ranong and Khlong Marui faults systems. These fault zones are oriented in the NE-SW from the Gulf of Thailand to the Andaman Sea through the Thai Peninsula. They cut across Paleozoic to Cenozoic sedimentary units and Mesozoic granitic bodies. More than 31 low- to medium-enthalpy hot springs are located along these strike-slip systems. The orientations of the fracture systems were extracted by remote sensing interpretations and field observations before being statistically analyzed in the rose diagram. Four lineament directions, orientated in the NE-SW, NW-SE, N-S, and E-W are interpreted according to the Riedel shear system of the NE-SW left-lateral shearing of the Ranong and Khlong Marui faults ultimately caused by the Indian-Eurasia collision. We expect that this tectonic and structural setting controls the non-volcanic geothermal system of Southern Thailand, however in what manner remains to be determined.