CHARACTERIZATION OF HYDROTHERMAL ALTERATION AND METAL ORE MINERALIZATION IN NAWANGAN, PACITAN, EAST JAVA, INDONESIA

• Main Author: Clementine Da Costa, Janice
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/63720
• Institution: Institut Teknologi Bandung

Pacitan region located in Southern Mountains extend along the southern coast of Java Island has many intrusions and geological structures that allow the presence of metalbearing ore mineralization which manifested as exposed hydrothermal alterations in the surface. The aim of this study is to identify hydrothermal alteration minerals dan metalbearing ore minerals in the study area. The research samples came from hand specimens from the results of exploration mapping that had been carried out before this research. Laboratory analysis carried out in this study are mineralogy analysis consisting of X-ray diffraction analysis, ore microscopy and petrographic analysis and spectroscopy analysis also a geochemical analysis conducted through X-ray flourescene analysis. Based on the mineralogical and geochemical analysis, the hydrothermal alteration observed in the study area consisted of propylitic alteration (mineral assemblage: calcite + serisite + quartz + epidote), seristic alteration (mineral assemblage: quartz+serisite) which developed in andesite-dacite rock units and sub-propylitic alteration (mineral assemblage: quartz+albit). which develops in basalite rock units. The ore minerals are chalcopyrite, spalerite, galena, magnetite and pyrite.