ALTERATION AND MINERALIZATION IN DEEP MILL LEVEL ZONE (DMLZ) LEVEL 2700 M, ERTSBERG DISTRICT, MIMIKA REGENCY, PAPUA

• Main Author: Permanik Isma Putri, Sarah
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/47261
• Institution: Institut Teknologi Bandung

Deep Mill Level Zone (DMLZ) is one of underground mining site belongs to PT Freeport Indonesia, located at Ertsberg Distric, Mimika Regency, Papua. Research area located in the underground mining site of Deep Mill Level Zone at coordinate 737.150–737.875 mE and 9.548.725–9.549.450 mN level 2700 m. This study use borehole data at 2650m-2750m level. Petrographic and mineragraphic analysis have been done respectively. Moreover, secondary data such as geochemical assay and quantitative XRD data also used in this study to get better understanding in alteration and mineralization in this study. The lithology in the study areas occupied by three rock units, Hornfels Unit, Marble Unit, and Diorite Unit. Alteration zone of this study area can be divided into six zones: (1) Felspar-Biotite-Anhydrite Zone, (2), Garnet-Pyroxene-Quartz Zone, (3) Epidote-Actinolite-Garnet Zone, (4) Magnetite-Talc Zone, (5) Magnetite-Anhydrite-Talc Zone, and (6) Diopside-Anhydrite-Forsterite Zone. Thus, mineralization zone in the study area comprised of three zones: (1) Magnetite-Chalcopyrite-Pyrite Zone, (2) Magnetite-Pyrite Zone, and (3) Magnetite-Bornite-Chalcopyrite Zone. As a result, zone of alteration and mineralization have been combined with geochemical data which can be conclude that it can be concluded that high grade Cu-Au in study area can be found in Magnetite-Talk Zone and also in Magnetite-Bornite-Chalcopyrite Zone.