Remote Sensing-Based Analysis of Potential Epithermal Gold Mineralization in the Sunda Arc Region of Bogor Regency
Silmi Afina Aliyan*1, Nikolas Anggi Putra Panjaitan2, Shafira Himayah1

1) Sains Informasi Geografi, Fakultas Pendidikan Ilmu Pengetahuan Sosial, Universitas Pendidikan Indonesia
2) Survey Pemetaan dan Informasi Geografis, Fakultas Pendidikan Ilmu Pengetahuan Sosial, Universitas Pendidikan Indonesia

Abstract

The Sunda magmatic arc that passes through the island of Java has played a role in the formation of gold deposits, particularly in the formation of low-sulfidation epithermal deposits in the Pongkor region, Bogor Regency. Currently, PT Antam Tbk. through its Gold Mining Business Unit (UPBE) manages an underground gold mine that produces pure gold and silver as its main products. Since 2016, UPBE Pongkor has experienced a decline in gold ore production, and various efforts have been made to explore and produce gold ore. Remote sensing technology, with the utilization of multispectral imagery, was used in this study to detect suspected zones of potential epithermal gold mineralization. This study used several geological indicators related to epithermal gold formation, such as the presence of propylitic and agrilic alteration minerals, lineament, and lithological characteristics. The processing techniques used in this study were Sabin^s Ratio algorithm and Crosta^s Directed Principal Component Analysis (DPCA). Both techniques were used to obtain information on the presence of surface minerals resulting from hydrothermal alteration, such as chlorite and smectite-illite minerals. This study integrates the indicators using the weight of evidence (WOE) method. The results of the study indicate that the presence of chlorite minerals is positively associated with the presence of gold deposits in the mining business permit (IUP) area of UBPE PT. Antam Pongkor has a value of 0.1492. The presence of lineaments is positively associated with gold deposits, with a value of 0.4726 at the lineament buffer class value of 0-100 meters. While the lithology of volcanic rocks is positively associated with gold deposits at values of 0.4760 and 0.3486. The results of the analysis show that epithermal gold deposits in Bogor Regency are associated with propylitic alteration types, with a distance buffer from the lineament of 0-100 meters, and are found in volcanic rocks in the form of basalt, andesite, and tuff. This association shows the distribution of suspected zones of potential epithermal gold mineralization in 5 areas around Bogor Regency, namely Parung Panjang, Cigudeg, and Jasinga sub-districts.

Keywords: Remote Sensing, Epithermal Gold Deposit, Sabin^s Ratio, Crosta^s Directed PCA, Weight of Evidence

Topic: Topic B: Applications of Remote Sensing