GEOLOGI DAN GEOKIMIA AIR PANASBUMI DAERAH BUMIAYU DAN SEKITARNYA, KABUPATEN BREBES, JAWA TENGAH

• Main Author: Sumpena, Lindawati
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/34286
• Institution: Institut Teknologi Bandung

Kata kunci : Bumiayu, geokimia air, panasbumi, kontrol struktur ii ABSTRACT The research was conducted at Bumiayu and Bantarkawung District, Brebes Regency, Central Java on UTM 49 S Zone with coordinate 268,000 – 274,000 mE and 9,192,000 – 9,201,000 mS, i.e. 54 km2 (9 x 6 km2). Geological mapping was conducted on the scale basis 1 : 25,000 to understand geological setting. Geochemistry analysis of geothermal surface water was done to characterize the geothermal system of the research area. The research area was identified to have geological structure-related geothermal system hosted on sedimentary rock. Geomorphology units are divided into 4 units, i.e. Bantarkawung Fault Zone Hills, Bantarkawung Fold Hills, Pangebatan Intrusion Hills, and Pemali Alluvial Plain. Geological units, from old to young, are Sandstone-Siltstone Intercalation Unit, Sandstone Unit, Pyroxene Andesite Unit, and Alluvial Deposit. Primary structures of geology are sedimentary structures, meanwhile secondary structures consist of the WNW – ESE to N – S trending reverse faults, the W – E to N – S trending folds, and the NE – SW trending strike-slip faults. Surface manifestations are warm to hot springs with temperature 40° - 71°C. The research area is interpreted to have 3 reservoirs controlled by geological structures, i.e. Pangebatan, Buaran, and Paguyangan. The reservoirs are interpreted to have similar temperatures ranging between 120° and 130° C in Sandstone Unit below 500 m depth. Total geothermal resources are from 17 to 18 MW.