#TITLE_ALTERNATIVE#

• Main Author: JAYA PERMANA , GANDA
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/13489
• Institution: Institut Teknologi Bandung

The research area is part of the East Java Southern Mountains Zone. Geomorphology of the research area consists of three units : volcanic hills, intrusion hill and karst hills. The shape of the river valleys in the research area resembles “V” shape with straight and rectangular flow patterns and genetic types of the river is dominated by consequent river. Stratigraphic of the research area consists of four lithological units, from old to young: pyroclastic unit (Late Oligocene-Early Miocene) equivalent to the Mandalika Formation, andesite intrusion unit (Early Miocene) equivalent to the intrusive rock unit, limestone unit (Middle Miocene) equivalent to the Wonosari Formation and alluvial deposit unit (Recent) equivalent to the Alluvium Deposit (not mappable on 1:12500 scale). Geological structures found in the research area consists of three right strike slip fault trending northwest-southeast and four left strike slip fault trending northeast-southwest which cut limestone unit or younger than Middle Miocene. Strike of the rock layer in the research area generally trending east-west with slope rock layer trending to the south. Hydrothermal alteration zone present in the research area are (1) quartzalunite- pyrophyllite-diaspore zone, (2) quartz-kaolinite-illity-dickitemontmorilonite zone, (3) quartz-feldspar-actinolite-epidot-chlorite-calcite zone, (4) quartz-sericite-pyrite zone and (5) silisification zone. Hydrotermal mineral assemblages temperatures range from 140-320oC which is within range of epithermal system. Vuggy silica texture, disseminated mineralization pattern and the presence of alunite, pyrophyllite, dickite and diaspore minerals showed that the research area is part of high sulphidation epitermal system.The formation of feldspar, actinolite, epidot, chlorite, calcite and the apperance of comb texture in quartz veins indicates a change of the system to low slphidation epitermal system.