LAUSR

Gunung Endut, which is located in Banten Province, Indonesia, holds considerable geothermal energy potential. Besides the existence of the Cikawah (CKW) and Handeuleum (HDL) hot springs, alteration mineral revealed on the surface as a result of contact with heat source are scattered in a relatively wide area to the west of the peak of the volcanic mountain. A geoelectrical method is an essential tool for mapping low resistivity distributions that infers the distribution of mineral alteration. Such an investigation had been conducted in 2006, however, the interpretation of the DC resistivity method was only based on its apparent results which could not precisely image the actual subsurface situation. In this study, we perform audiomagnetotelluric (AMT) technique to obtain resistivity variations at deeper depths. Based on the interpretation results of all the geoelectrical methods, the distribution of impermeable zone with low resistivity is detected in the eastern part of the study area, approximately 3 km to the west of Gunung Endut’s peak and 2 km east of the CKW hot spring. The discovery of alteration minerals in these regions supports the interpretation results. The existence of this strong alteration is likely to be controlled by a trending NW-SE fault structure, estimated from the striking analysis and is augmented with both geochemistry analysis and relative gravity study carried out previously. These facts lead to the conclusion that the existence of a geothermal reservoir is estimated between the manifestations of the CKW hot spring and peak of Gunung Endut.