Abstract:
Kamojang geothermal field is located in a 1.2 to 0.452 Ma, Quarternary volcanic caldera system. Around the geothermal field, there are several volcanoes (cinder cones) which include: Gunung sanggar, Gunung ciharus, Gunung jawa, Gunung pasir jawa and Gunung cakra (here “gunung” means “mount”). The activity of this volcanic complex contributes greatly to the presence of Kamojang geothermal field, which forming steam dominated system with high temperature around 250°C. The system has capacities of 260 MWe and 140 MWe. Volcanic rocks found around the geothermal field have been altered in general and some of them are difficult to be identified their initial character. Thus, it is necessary to study alteration rocks and lithogeochemistry of a geothermal field. Based on this idea, this study uses some methods consisting of: petrographic, geochemical and alteration box plot analysis. The analyses have been conducted for the surface samples and alteration rocks of cutting from Well KMJ-49. This study is expected to improve the understanding on the characteristics of Kamojang geothermal field. Al and CCPI calculation results indicate that the surface samples have a value ranging from 20 to 34 Al and CCPI ranges from 63 to73. While subsurface samples have Al values around 15-46 and CCPI ranges from 68 to 86. The relations of CPPI and AT will be reflected in the texture and mineralogy of the type and condition of the rock.
Page(s):
21-32
DOI:
DOI not available
Published:
Journal: International Journal of Economic and Environmental Geology, Volume: 3, Issue: 2, Year: 2012