Hydrothermal Alteration Study in Malabar Area, Northern Part of the Wayang Windu Geothermal Field, Indonesia

Abstract

The Malabar area, northern part of the Wayang Windu geothermal field is situated in the West Java province of Indonesia. Hydrothermal alteration study were conducted in the Malabar area to characterize surface and subsurface hydrothermal alteration. Rock samples were collected from surface and subsurface, subjected to petrographic observations, X-ray diffraction and fluid inclusion analyses.
New data of surface hydrothermal alteration was identified in the Malabar area. These manifestations could indicate an extension of geothermal potential in northward from the developed area. The hydrothermal alteration is spatially associated with faults and fractures. The surface hydrothermal alteration can be grouped into two types: propylitic and advanced argillic alteration. While three types of hydrothermal alteration including advanced argillic, subpropylitic and propylitic alteration was observed in the subsurface of MBA-2 and MBB-1 wells.