Karakteristik Mineralisasi Endapan Epitermal Pada Prospek Arinem Di Kabupaten Garut, Jawa Barat

Abstract

The Arinem prospect is from the Sunda magmatic arc (Sunda Arc) which is located in the Indonesian archipelago on the south side of the Sundaland and the Eurasian plate. In exploration of mineral ore deposits, it is important to have an understanding of minerals. This study aims is to identify the mineralization characteristics of the epithermal deposits of the Arinem prospect in the form of texture, morphology, size and presence of ore minerals which can assist to interpretate the paragenesis afterward. The study was carried out by observing the surface outcrop samples as well as from the DH-0055 drill hole level 170-210 meters. A total of 16 samples of surface outcrops and 12 core drilling samples were analyzed by megascopic and microscopic refractive-reflection polarization and 4 of the 12 selected core drilling samples, crushed into clay-sized fractions and analyzed using the x-ray diffraction method to detect clay minerals and other altered mineral associations. Quartz textures that presented at the study site were based on megascopic observations, generally dominated by saccharoidal, colloform, comb, lattice bladed, and banded textures. The identified ore minerals were generally dominated by base metal minerals with paragenesis respectively, pyrite chalcopyrite, galena, sphalerite, limonite, jarosite and malazite. Alteration at the research location is characterized by the presence of quartz-chlorite-epidote-calcite as a feature of the propylitic zone, and quartz-kaolinite-illite which characterizes the argillic zone. The results of the study concluded that the type of mineralization in the Arinem prospect was a low sulfidation epithermal type.