Stratification characteristics of subsurface rock structure geothermal manifestations at Telaga Tujuh Warna Bukit Daun, Bengkulu, Indonesia using magnetic methods

Abstract

Geothermal energy is one of the mainstay of future alternative energy in Indonesia. One area that is believed to have geothermal potential is Telaga Tujuh Warna Village in Lebong Regency, Bengkulu Province, Indonesia. Manifestations of hot springs, hot mud pools, geysers, sulfur, and the presence of steam around the lake are our beliefs about the existence of geothermal sources in the area. The purpose of this study was to determine the stratigraphic characteristics of the subsurface rocks of the Telaga Tujuh Warna geothermal manifestation area. Magnetic method was used to determine the subsurface rock stratification of the Telaga Tujuh Warna area. The magnetic method is carried out based on the measurement of geomagnetic anomalies caused by differences in the contrast of the magnetic susceptibility or permeability of the surrounding area. Based on 2D modeling of the subsurface lithology the area was compiled by of volcanic breccia (0 SI), basalt (1.03 SI, 0.205 SI, 0.2 SI, 0.23 SI, 0.207 SI), altered tuff-breccia rock (-0.041 SI), andesite rock (0.12 SI, 0.13 SI), altered tuff (-0.001 SI, -0.01 SI), and breccia-andesite rock (0.156 SI, 0.049 SI), tuff (0.027 SI), and altered andesite (-0.004 SI).