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Journal : Journal of Geoscience, Engineering, Environment, and Technology

The Metamorphic Rocks-Hosted Gold Mineralization At Rumbia Mountains Prospect Area In The Southeastern Arm of Sulawesi Island, Indonesia Hasria, Hasria; Idrus, Arifudin; Warmada, I Wayan
Journal of Geoscience, Engineering, Environment, and Technology Vol 2 No 3 (2017): JGEET Vol 02 No 03 : September (2017)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (963.108 KB) | DOI: 10.24273/jgeet.2017.2.3.434

Abstract

Recently, in Indonesia gold exploration activities  are not only focused along volcanic-magmatic belts, but also starting to shift along metamorphic and sedimentary terrains. The study area is located in Rumbia mountains, Bombana Regency, Southeast Sulawesi Province. This paper is aimed to describe characteristics of alteration and ore mineralization associated  with metamorphic rock-related gold deposits.  The study area is found the placer and  primary gold hosted by metamorphic rocks. The gold is evidently derived from gold-bearing quartz veins hosted by Pompangeo Metamorphic Complex (PMC). These quartz veins are currently recognized in metamorphic rocks at Rumbia Mountains. The quartz veins are mostly sheared/deformed, brecciated, irregular vein, segmented and  relatively massive and crystalline texture with thickness from 1 cm to 15.7 cm. The wallrock are generally weakly altered. Hydrothermal alteration types include sericitization, argillic, inner propylitic, propylitic, carbonization and carbonatization. There some precious metal identified consist of native gold and ore mineralization including pyrite (FeS2), chalcopyrite (CuFeS2), hematite (Fe2O3), cinnabar (HgS), stibnite (Sb2S3) and goethite (FeHO2). The veins contain erratic gold in various grades from below detection limit <0.0002 ppm to 18.4 ppm. Based on those characteristics, it obviously indicates that the primary gold deposit present in the study area is of orogenic gold deposit type. The orogenic gold deposit is one of the new targets for exploration in Indonesia
Analysis of Content, Source and Impact of Heavy Metals in Sombori Island, Central Sulawesi, Indonesia Hasria, Hasria; Usman, Ida; Saeri, Karim; Nasaruddin; Sara Septiana; Rais, Mohammad; Harisma, Harisma; Musrajab, Silo
Journal of Geoscience, Engineering, Environment, and Technology Vol. 11 No. 1 (2026): JGEET Vol 11 No 01 : March (2026)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jgeet.2026.11.1.23856

Abstract

A study was conducted on Sombori Island, Central Sulawesi. The purpose of this study was to determine the content of heavy metals and the origin of contamination and the impact of heavy metal contamination. Seawater samples totaling 30 stations were analyzed in the form of total suspended solids (TSS), pH, salinity and heavy metal content of hexavalent chromium (Cr6+) and nickel (Ni) using Atomic Absorption Spectrometry (AAS) analysis. The heavy metals chromium (Cr) and nickel in the sediment were analyzed using flame Atomic Absorption Spectrometry (AAS). The results of the study showed that heavy metals in seawater in the form of Ni are still safe for the marine ecosystem of the research area. However, the heavy metal Cr6+ has contaminated several marine waters stations because it has exceeded the established quality standards so that it can have a negative impact on the marine ecosystem including humans through the food chain. The content of heavy metal Cr in marine sediments has not passed the established sediment quality standards. However, for heavy metal Ni in sediment, it has exceeded the established sediment quality standards so that it has had a negative impact on the marine ecosystem that lives and feeds around/on the sediment including humans through the food chain. Sources of contamination of heavy metals in water and sediment are from the weathering of ultramafic rocks containing heavy metals, mining activities, shipping activities using fossil fuels, the use of ship paint containing heavy metals, solid waste from ships containing heavy metals and domestic waste.