| Title | Regional Structure Control on Geothermal Potency in West Java, Indonesia |
|---|---|
| Authors | Ahmad FAUZI, Haryadi PERMANA, Sri INDARTO, E, Gaffar |
| Year | 2015 |
| Conference | World Geothermal Congress |
| Keywords | Regional Structure, Geothermal, West Java, Fault |
| Abstract | Indonesia has been recognized to have large geothermal potential, possibly up to 4000 MWe. The resources are distributed at 256 geothermal areas and among of them, 40 locations are located in West Java Indonesia. Geothermal installed capacity in West Java is 839 MWe out of 1197 MWe of all geothermal capacity in Indonesia. Regional structure is very important in the geothermal system in providing conduits for magma ascent. In addition, the structure also provides the secondary permeability for the hydrothermal fluids, meteoric water, to be migrated, interacted and finally accumulated in the geothermal reservoir. Unlike geothermal fields in Sumatra that are controlled by the Sumatra Fault Zone, the geothermal locality in Java seems to be distributed randomly. No single regional structure has been associated with geothermal system in West Java. However, the enhanced regional Bouger anomaly of Java compiled with Regional Geology show that there are major structures, which are associated with the geothermal fields in West Java. The major structures in West Java that controlled the geothermal system are a Major Arc Parallel structure of West Java Fault trending at NW-SE and circular structures. These major structures controlled and associated with volcano-magmatic product in West Java. Those structures also correlate spatially with recent active hydrothermal activity, and also correspond with a fossilized geothermal system as indicated by hydrothermal mineralization occurrences in West Java associated with the structures. The kinematic analysis of regional structure reveals the extensional condition in West Java at NNW-N-NNE trending. The consistency of extensional setting in active and fossil geothermal system indicates that the structure control in geothermal system in West Java, is driven by regional structure. |