Mineral Identification of Iron Ore Deposits in Menggamat, South Aceh through Mineralogical Analysis

Abstract

Iron ore mineralization in the Menggamat area, Kluet Tengah District, South Aceh Regency, has been exploited by local communities; however, detailed mineralogical studies remain limited. This study aims to identify the main ore minerals, associated minerals, microscopic textures, and paragenetic sequence of iron ore deposits using an integrated mineralogical approach. Field investigations were conducted in Simpang Dua and Simpang Tiga villages, where 31 rock samples were collected through channel sampling, chip sampling, and grab sampling methods. Macroscopic observations were followed by petrographic and mineragraphic analyses using reflected and transmitted light microscopy. The results indicate that magnetite and hematite are the dominant iron ore minerals, accompanied by sulfide minerals such as pyrite and chalcopyrite. Gangue and alteration minerals include quartz, garnet, and carbonate minerals. Mineragraphic observations reveal abundant replacement, crosscutting, intergrowth, and inclusion textures, indicating a multistage mineralization process. Magnetite represents the earliest mineral phase, subsequently replaced by hematite through oxidative alteration, followed by metasomatic replacement by garnet and late-stage quartz veining. These mineralogical characteristics and textural relationships suggest that the iron ore deposits in the study area are genetically related to skarn-type mineralization associated with hydrothermal and metasomatic processes. The results provide essential baseline data for sustainable mineral resource management and preliminary environmental assessment in South Aceh.