Geothermal Geophysical Study of Mt. Papandayan, Garut District, West Java Indonesia

Abstract

Papandayan volcanic complex (1,100 - 2,665 m asl) is dominated by young Quaterary andesitic rocks, showing cones, faults, dome and collapse structures. Extensive alteration of inner and outer volcanic flank with high tempearature fumaroles (80–150oC), indicates that H2S gases affect on fresh rocks. The gas geothermometry shows 250oC or higher subsurface temperature, suggesting the low temperatur gas may take place below the older Tegal Alun-Alun volcanics. Magneto-telluric (MT) survey results for the north and north-east slopes of Papandayan indicates resistivity variations of conductive and resistive layers. Low frequency (1000 Ohm-m) presumably indicates deep hard rocks, as a part of heat source media.