The Application of Electrical Resistivity Tomography using Wenner-Schlumberger Arrays Configuration to Identify the Geological Structure in Kancah Warm Spring, West Java Indonesia

Abstract

Kancah warm spring is located in the southern part of Tangkuban Perahu Volcano, in West Java Indonesia. This warm spring has a temperature 470 C and a pH of 3 and it is used as a source of water for nearby tourist attractions. This warm spring has a large discharge, with the source thought to be from subsurface water associated with Tangkuban Perahu Volcanic complex. Knowing the source and geological control of this warm spring is one way to further identify the Tangkuban Perahu geothermal system, especially its permeability. For that reason, this research aims to using Electrical Resistivity Tomography (ERT) method to identify the geological structure that controls the appearance of geothermal manifestation using the resistivity method with Wenner – Schlumberger arrays configuration. The study starts with lineament study using DEM to identify the structure in surface and then determine the geometry of subsurface geological structures are using the electrical resistivity tomography (ERT) method using the Wenner - Schlumberger configuration. with a length 320 meters of each line and the electrode spacing is 10 m. The results of the interpretation of satellite images show that there is a lineament which is interpreted as a fault structure with a NE-SW direction that is right at the location of the discharge of the warm spring. There are 3 - 4 faults identified in each profile, some of the faults identified beneath the Kancah spring and may controlled the warm spring. These faults are a permeable that flows hydrothermal fluids from the subsurface to the surface in the form of warm spring..The lithology beneath of Kancah warm spring are dominated by breccia pyroclastics, clays, and a small amount of andesite igneous rocks.