Geology and ore characteristics of low sulfidation epithermal gold prospect in Cihaur Region, Simpenan, Sukabumi, West Java, Indonesia

• Main Authors: Laksana, Bayu Aji Dwi, Idrus, Arifudin, Husein, Salahuddin, Faruqi, Muhammad Dzulfikar, Sukadana, I. Gde
• Format: Conference Proceeding
• Language: English
• Subjects: Andesite; Base metal; Breccia; Calcite; Clay minerals; Covellite; Galena; Gangue; Geology; Gold; Illite; Kaolinite; Mineralization; Minerals; Petrography; Quartz; Sulfidation; Tuff; X-ray diffraction; Zincblende
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0126121

The study area is located in Cihaur Village, Sukabumi, West Java, occupied by Jampang Formation which hosts numerous gold mineralization in West Java. This paper discusses the geology and ore characterization based on field mapping, thin section petrography, and X-Ray Diffraction (XRD) to define the rock and hydrothermal alteration, and ore microscopy to identify the type of ore minerals. The geology of the research area consists of tuff breccia, andesite, and dacite units, with three alteration zones, such as silicification, argillic, and propylitic. The alteration characterized by quartz as a dominant secondary mineral (silicification), clay minerals such as kaolinite and illite (argillic), chlorite, albite, calcite, and minor secondary quartz (propylitic), based on petrography and XRD analysis. The area mineralization is dominantly controlled by quartz vein with N 3300 E orientation, showing crustiform, comb, chalcedony, saccharoidal, acicular, cockade, and stockwork textures corresponding to the low sulfidation epithermal system. On surface (about 720 – 740 masl), mineralization is characterized by gold with quartz and oxide manifested as gangue mineral, while mineralization below the surface (about 640 – 680 masl) characterized by base metal with ore minerals such as galena and sphalerite, and supergene minerals such as covellite.