ALTERASI HIDROTERMAL ENDAPAN SINABAR DAERAH BUKIT TEMBAGA, IHA – LUHU, PULAU SERAM, MALUKU
HYDROTHERMAL ALTERATION OF CINNABAR DEPOSIT IN TEMBAGA HILL, IHA – LUHU - SERAM ISLAND, MALUKU
Abstract
Iha – Luhu area is located in the western part of Seram Island, which is about 59.2 km from city of Piru. Geographically, it is located at 128o0’35” to 128o2’42”East Longitude and 3o20’40” s.d 3o22’05”South Latitude and is included in Huamual sub-district, West Seram Regency, Maluku. Stratigraphy of Iha – Luhu is composed of metapelitic rock and low grade metamorphic lithologies, namely meta quartz – muscovite sandstone units and quartz – muscovite phyllite unit and is unconformaby covered by alluvial deposits.
Research area consists of three hydrothermal alteration zones which are mentioned as illite±kaolinite alteration zone, illite±chlorite alteration zone and Illit±smectite±kaolinite alteration zone. Illite±kaolinite alteration zone is characterized by assemblage of clay minerals, presumably illite and kaolinite. This alteration is associated with quartz-muscovite meta-siltstone and dominant occurred to quartz-muscovite meta-sandstone. Intensity of alteration is moderate to strong altered which mainly describing percentage of alteration mineral presence more than 75%. Based on assemblage of kaolinite and illite alteration minerals thus illite±kaolinite alteration zone was formed at temperatures <220o-300o C. Illite±chlorite alteration zone is associated with fracture-related mineralization and disseminated enrichment of cinnabar ore deposits where alteration pattern is a pervasive alteration show. This zone is characterized by presence of mica (illite) clay mineral and chlorite and quartz as well. Illite±chlorite alteration is more dominantly associated with quartz-muscovite phyllite and quartz-muscovite meta-siltstone and spread over in the middle of Bukit Tembaga. Formation Temperature of this alteration zone is estimated at 250o – 300o C.
Illite±smectite±kaolinite alteration zone spread widely on top of Bukit Tembaga to lowlands and reaching area of > 9.6 Km2. This alteration covers illite ± chlorite and illite ± kaolinite alterations with pervasive alteration pattern and strong altered alteration. Clay in this zone occurred due to alteration of muscovite/sericite and plagioclase minerals. Presence of smectite in this alteration zone reflects vertical depth that is relatively far from ore zone or at top of formation with temperature tend to be lower than illite and kaolinite minerals. Formation temperature of this alteration zone is estimated at 220o-300o C.
Downloads
References
Corbett, G.J. dan Leach, T.M., 1996. Southwest Pacific Rim Gold-Copper System: Structure, Alteration and Mineralization SEG Special Publication No.6.Auckland, New Zealand.
Kemp, G., Mogg, W., 1992. A re-appraisal of the geology, tectonics and prospectivity of Seram Island, Eastern Indonesia. Proceedings of Indonesian Petroleum Association 21st Annual Convention, 521–552
Kingston Morrison, K., 1995. Important Hydrothermal Minerals and Their Significance. Geothermal and Mineral Services Division, Kingston Morrison Limited.
Lawless, J.V., White, P.J., 1997. Important Hydrothermal Minerals and Their Significance. Geothermal and Mineral Services Division, Kingston-Morrison Ltd., 7th edition.
Patria, A., Hall, R. 2018. Oblique Intraplate Convergence of the Seram Trough, Indonesia. Bulletin of the Marine Geology, 33, 41 - 58
Pownall, J.M., Hall, R. and Watkinson, I.M. 2013. Extreme extension across Seram and Ambon, eastern Indonesia: evidence for Banda slab rollback. Solid Earth, 4: 277–314.
Reyes, A.G., 1990. Petrology of philipine geothermal systems and the application of alteration mineralogy to their assessment. Journal of volcanology and geothermal research, 43, 279-330.
Samalehu, H., 2021. Geologi, karakteristik dan mineralisasi hidrotermal batuan metamorf kompleks Tehoru dan Taunusa di Pulau Seram, Indonesia. Disertasi. Universitas Gadjah Mada, Yogyakarta.
Thompson, A.J.B, dan Thompson, J.F.H. 1996. Atlas of Alteration A Field and Petrographic Guide to Hydrothermal Alteration Minerals. Geological Association of Canada, Mineral Deposits Division, Department Of Earth Sciences, 118p.
Tjokrosapoetro, S., Achdan, A., Suwitodirdjo, S., Rusmana, E.,Abidin, H.Z., 1993. Pemetaan Geologi lembar Ambon sekala 1 : 250.000. Pusat Penelitian dan Pengembangan Geologi, Bandung.
Tjokrosapoetro, S., Budhitrisna, T., 1982. Geology and tectonics of the northern Banda Arc. Bulletin of the Indonesian Geological Research and Development Centre, 6, 1–17.
White, T.L., 1996. Cryogenic Alteration of Clay and Silt Microstructure, Implication for Geotechnical Properties. Ottawa: Carleton University.
Copyright (c) 2022 Buletin Sumber Daya Geologi
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Penulis yang naskahnya diterbitkan menyetujui ketentuan sebagai berikut:
Hak publikasi atas semua materi naskah jurnal yang diterbitkan/dipublikasikan dalam situs Buletin Sumber Daya Geologi ini dipegang oleh dewan redaksi dengan sepengetahuan penulis (hak moral tetap milik penulis naskah).
Ketentuan legal formal untuk akses artikel digital jurnal elektronik ini tunduk pada ketentuan lisensi Creative Commons Attribution-ShareAlike (CC BY-SA), yang berarti Buletin Sumber Daya Geologi berhak menyimpan, mengalih media/format-kan, mengelola dalam bentuk pangkalan data (database), merawat, dan mempublikasikan artikel tanpa meminta izin dari Penulis selama tetap mencantumkan nama Penulis sebagai pemilik hak cipta.
Naskah yang diterbitkan/dipublikasikan secara cetak dan elektronik bersifat open access untuk tujuan pendidikan, penelitian, penyelidikan, dan perpustakaan. Selain tujuan tersebut, dewan redaksi tidak bertanggung jawab atas pelanggaran terhadap hukum hak cipta.
