STUDY OF ALTERATION, MINERALIZATION, AND CHARACTERISTICS OF RAMBA JORING GOLD ORE, HIGH SULPHIDATION EPITHERMAL DEPOSIT OF MARTABE AREA, BATANGTORU SUB-DISTRICT, SOUTH TAPANULI REGENCY, NORTH SUMATERA PROVINCE

• Main Author: Saraswani, Risa
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/69854
• Institution: Institut Teknologi Bandung

The study was conducted on Ramba Joring Prospect, at Martabe Gold Mine owned by PT. Agincourt Resources at Batangtoru Sub-District, South Tapanuli Regency, North Sumatera Province. This research aims to determine the alteration, mineralization, distribution of gold, and characteristics of gold ore and its relation to the value of gold recovery in the study area. The methods used in this research include core logging, petrographic and mineragraphic analysis, size-by-size assay test, diagnostic leaching test, and pulverized bottle roll test. From the analysis, the lithological units identified consist of Andesite Hornblenda Unit and Phreatomagmatic Breccia Unit. The alteration zones developed in the study area are massive-vuggy silica zone, advanced argillic zone, and argillic zone. Furthermore, the study area was divided into three sulfide sulfur zones, including low sulfide sulfur zone (SCIS <2%), the medium sulfide sulfur zone (2% <SCIS <5%), and the high sulfide sulfur zone (SCIS >5%). Mineralization that occurred in each sulfide sulfur zone shows the presence of different ore minerals depending on the alteration zone. Gold ore is distributed in rocks with massive-vuggy silica alterations and advanced argillic alterations. According to its sulfide sulfur zone, gold ore is dominantly distributed in the low sulfide sulfur zone and the least in the high sulfide sulfur zone. Gold ore in the study area is dominantly distributed in very fine size particles, associated with sulfide, carbonate, and silicate minerals. Recovery value is affected by alteration, mineral association, percentage of sulfide sulfur, and gold texture.