KARAKTER DAN TIPE MINERALISASI HIDROTERMAL DI WILAYAH BOMBANA BERDASARKAN STUDI MINERALOGI DAN GEOKIMIA

I. Setiawan, S. Indarto, AF. Ismiyanto, Sudarsono Sudarsono

Abstract


Bombana gold mineralization occurs within metamorphic rocks hosted environment, and it's not yet reported having connection with magmatisme/volcanisme. Therefore most ore mineral deposits have to be related with volcanisme bearing metallic mineralization. The aim of this study is to explain the character and types of gold deposit using petrography, mineragraphy, fluid inclusions, AAS, and geochemistry methods.
Bombana area formed by orogenic activities which is composed by metamorphic rocks mainly consists by greenschist facies and ultra mafic rocks. Petrographically rocks called as garnet glaukofane amphibol schist, peridotite, serpentinite, sandstone meta, limestone meta, andesite meta, and altered rocks. While based on major elements composition, their parent rocks has ultrabasic-acidic rocks composition, formed peridotite to andesite.
Gold mineralization of Bombana area indicates an epithermal-mesothermal type, which is exhibited by hydrothermal evidences such as crosscut veins after foliation and alteration at vicinity of quartz/calcite veins. These indicate that mineralization resulted by hydrothermally process and formed after metamorphism.
Ore minerals consisted of gold, pyrite, chalcopyrite, goethite, lepidocrocite and cinabar and commonly associated with quartz veins as mineralized fluids suggested as low salinity (0,18-1,78)% NaCl equivalent and water rich mineralized fluid, at (210-350)ºC temperatur ranges.


Keywords: Bombana, volcanic rocks, epithermal, metamorphism


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References


Barnes H.L., 1979. Geochemistry of Hydrothermal Ore Deposits, Second Edition. A Willey Interscience Publication, John Willey and Sons

Bateman, A.M., 1951. The Formation of Mineral Deposits, Economic Mineral Deposits, Second Edition, , John Willey and Sons, Inc, ISBN 0 471 0577 8

Carlile, J.C. and Mitchell.A.H.G., 1994. Magmatics arcs and Associated Gold and Copper Mineralization in Indonesia. In T.M. van Leeuwen, J.W. Hedenquist, L.P. James and J.A.W.S. Dow (Editors), Indonesian Mineral Deposits-Discoveries of the Past 25 Year. Jour. Geochem. Explo.,50: 91-142

Garwin, S., Hall, R., Watanabe, Y., 2005. Tectonic Setting, Geology, and Gold and Copper Mineralization inCenozoic Magmatic Arcs of Southeast Asia and the West Pacific. Society of Economic Geologists, Inc., Economic Geology 100th Anniversary VolumE, pp. 891–930

Groves D.I., Condie K. C., Goldfarb R.J., Hronsky J. M.A., Vielreiche R. M., 2005. Secular Changes in Global Tectonic Processes and Their Influence on the Temporal Distribution of Gold-Bearing Mineral Deposits, 100th Anniversary Special Paper, 2005 Society of Economic Geologists, In Economic Geology, v. 100, pp. 203–224

Grooves D.I., R.J. Goldfarb, M. Gebre Mariam, S.G. Hagemann, and F. Robert, 1998. Orogenic gold deposit: A proposed classification in the context of their crustal distribution and relationship to other gold deposit types. Ore Geology Reviews. Elsevier

Hall R.,The Eurasian SE Asian Margin As A Modern Example Of An Accretionary Orogen, 2009, Earth Accretionary Systems in Space and Time. The Geological Society of London,Special Publication.

Hamilton W. (1979). Tectonics of the Indonesian region. US. Geol. Surv., Prof. Pep. 1078.

Hedenquist, J.W., Izawa E., Arribas A., White N.C., 1996. Epithermal Gold Deposits: Styles, Characteristics and Exploration. Resource Geology Special Publication Number 1, Published by The Society of Resource Geology

Idrus A., Fadlin, Prihatmoko S., Warmada I.W., Nur I., Meyer F.M., 2012. The Metamorphic Rock-Hosted Gold Mineralization At Bombana, Southeast Sulawesi: A New Exploration Target In Indonesia, Vol No.1, Maret 2012, ISSN 182905819

Idrus A., Warmada I. W., Nur I, Sufriadin, Imai A., Widasaputra S., Marlia S.I., Fadlin, Kamrullah., 2010. Metamorphic Rock-Hosted Orogenic Gold Deposit Type As A Source Of Langkowala Placer Gold, Bombana, Southeast Sulawesi, Indonesia. Proceedings PIT IAGI Lombok , The 39th IAGI Annual Convention And Exhibition

Kisman, Ernowo dan Suwargi E.,, Prospeksi Endapan Emas di Kabupaten Bombana Provinsi Sulawesi Tenggara, dalam http://psdg.bgl.esdm.go.id/ didownload 08/02/2012.

Miyashiro, A. (1974). Volcanic Rock Series In Island Arcs And Active Continental Margins. American Journal of Science, 274: 321–355.

Setiawan I., Zulkarnain I, Indarto S., Sudarsono dan Ismayanto A.F., 2010, Mineralisasi pada batuan pra Tersier: Kasus Bombana. Laporan teknis penelitian, tidak dipublikasikan.

Simandjuntak T.O., Surono, dan Sukido., 1994. Geologi Lembar Kolaka, Sulawesi, skala 1: 250.000, Pusat Penelitian dan Pengembangan Geologi Bandung.

Surono dan Tang H.A.,2009. Batuan Pembawa Emas Primer Dari Endapan Emas Sekunder Di Kabupaten Bombana, Sulawesi Tenggara, Berdasarkan Interpretasi Inderaan Jauh. Proceedings PIT IAGI Semarang, The 38th IAGI Annual Convention And Exhibition

Surono, 1998. Geology and Origin of The Southeast Sulawesi Continental Terrane, Indonesia. Media Teknik No. 3 Tahun XX

Surono, 2010. Geologi Lengan Tenggara Sulawesi, Publikasi Khusus, Badan Geologi, Kementrian Energi dan Sumberdaya Mineral.

William H., Turner F.J., Guilbert C.M., 1954. Petrography, An Introduction to the Study of Rocks in Thin Section, University of California, Berkeley, W.H. Freeman and Company.




DOI: http://dx.doi.org/10.33332/jgsm.geologi.v22i3.115

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