Indikasi mineralisasi epitermal emas bersulfi da rendah, di Wilayah Kecamatan Bonjol, Kabupaten Pasaman, Sumatera Barat

Hamdan Z. Abidin, Bhakti H. Harahap


Bonjol gold prospect, known as Old Dutch Gold mine, consists of several ore bodies (Malintang, Balimbing, Lubang Sempit, Lubang Belanda and Lubang Perak). The deposit hosts within the altered volcanic rocks known as Gunung Amas Formation of Early Miocene age (9.3 ± 0.4 - 11.9 ±1.0 Ma). This formation consists of various rock types such as rhyolitic tuff, volcanic breccia, dacitic tuffs and rhyolites. These rocks are moderate to strongly alter. Mineralogy of the deposit consists of gold and silver with minor pyrite, sphalerite and galena. Besides this, hematite, jarosite and manganese are also present as supergene minerals. Ore minerals are found within quartz veins ranging from few centimetres to tens of metres thick. The veins are characterized by crustiform, comb, vuggy, botroyidal, layering and bladed. Quartz is a dominant mineral as hydrothermal alteration in addition to illite, dickite, monmorillonite, kaolinite, chlorite, smectite, natrolite, nontronite, calcite, halloysite, palygorskite, muscovite, sepiolite, analcime, heulandite, clino-chlor, zircon, zoisite, laumontite, alunite, biotite and erionite. The presence of these secondary minerals could be classifi ed into prophylitic, argillic and advanced argillic types. Analytical result of gold–bearing quartz vein indicates higher content of gold (0.3%) and silver (400 ppm). In contrast, the content of sulphide minerals (Cu, Pb, and Zn) is very low (< 100 ppm). Combined geology, mineralogy, textures and alteration minerals, it is concluded that gold deposit in the area shows an indication of a low sulphidation epithermal type within Gunung Amas Formation.



gold; low sulphidation; epithermal type; gunung amas; Bonjol


Abidin, H.Z. dan Harahap, B.H., 2005. Laporan penelitian geologi dan petrologi di daerah Bonjol dan sekitarnya. Pusat Survei Geologi. Tidak terbit.

Abidin, H.Z., Harahap, B.H., dan Elhami, Y., (dalam proses). Pb-Zn-Ag deposit at Tanjung Balit, Limapuluh Kota Regency, West Sumatra. Joint Convention Bali 2007. The 32th HAGI and IAGI Annual Convention and Exhibition. Patra Bali, 19-22 November 2007.

Almaden Minerals, 2007. Vein systems and types of deposits.

Bambang, S. dan Yudawinata, K., 2001. Review of mineralization along the Sunda - Banda magmatic arc. International on marginal field development Seminar. Sheraton Hotel, Bandung. Direktorat Inventarisasi Mineral. h. 1-12.

Basuki, A., Aditya S.D., and Sinambela, D., 1994. The Gunung Pongkor gold-silver deposit. West Java, Indonesia. J. Geochem. Explor. 50. h. 371-391.

Berger, B.R. and Henley, R.W., 1989. Recent advances in the understanding of epithermal gold-silver deposts-with special reference to the western United States. Econ. Geol. Monograph, 6, h. 405-423.

Berger, B.R. and Bonham, H.F., Jr., 1990. Epithermal Au- Ag deposits in the western United States. J. Geochem. Explor. 36, h. 103-142.

Bonham, H.F., Jr.,1986. Models for volcanic-hosted epithermal precious metal deposits:Areview: Proceedings Symp. 5: Volcanism hydrothermal systems and related mineralization, I.A.V.C.E.I., Hamilton. h. 13-18.

Brian, L., Martin, J., and Bronto, S., 2004. The Purnama gold deposit in the Martabe District of North Sumatera, Indonesia. Dalam persiapan. Laporan Internal PT. Horas Nauli. Tidak terbit.

Bronto, S. dan Hartono, U., 2003. Strategi penelitian emas berdasarkan konsep pusat Gunung Api. Prosiding Kolokium Energi dan Sumber Daya Meneral 2003, Balitbang ESDM, Bandung, h. 172-289.

Bronto, S. dan Hartono, U., 2006. Potensi sumber daya geologi di daerah cekungan Bandung dan sekitarnya. Jurnal Geologi Indonesia, 1, h. 9-18.

Carlile, J.C. and Mitchell, A.H.G., 1994. Magmatic areas and associated gold and copper mineralization in Indonesia. In T.M. Van Leeuwen, J.W. Hedenquist, L.P. James and J.A.S. Dow (eds.). Indonesian Mineral Deposits- Discoveries of the past 25 years. J. Geochem. Explor., 90, h. 91-142.

Corbett, G.J. and Leach, T.M., 1995. S.W. Pacifi c Rim Au/ Cu Systems: Structure, Alteration and Mineralization. 148 h.

Crow, M.J. and Van Leeuwen, T.M., 2005. Metallic mineral deposits. Sumatra, geology, Resources and Tectonic evolution. Geol. Surv. Memoir, 31, h. 147-174.

Grey, D.W.J., 1935. Note on Balimbing Mine, west coat of Sumatra. Bull. Inst. of. Mining and Metallurgy, h. 1-2.

Hamilton, W. 1979. Tectonic of the Indonesian Region, U.S.G.S. Prof. Paper 1078.

Haiba, D.O., Bethke, P.M., Heald, P., and Foley, N.K., 1985. Geologic, Mineralogic, geochemical characteristics of volcanic-hosted epithermal precious metal deposits. In Geology and Geochemistry of epithermal Systems; eds.

Berger, B.R. and Bethke, P.M. Reviews in Economic Geology, Soc. Econ. Geol., 2, h.129-168.

Harris, L., 1986. Structural control of epithermal gold mineralization in the Mangani and Balimbing areas, Sumatra, Indonesia. 246 Barker Road Subiaco 6008, Western Australia. Tidak diterbitkan.

Heald, P., Foley, N.K., and Hayba, D.O., 1987. Comparatine anatomy of volcanic –hosted epithermal deposits: acid sulfate and adularia-sericite types. Econ. Geol. 82, h. 1-26.

Henley, R.W., 1985. Ore transportation and deposition in epithermal environments. Proceeding Symposium on stable isotope and fluid processes in mineralization. Geol. Soc. Aust. Spec. Publ. 33h.

Henley, R.W. and Hoffman, C.F., 1987. Gold: sources. Proc. Pacifi c Rim Congress 87. Aust. Inst. Min. Met. h. 159-168.

Henley, R.W., 1991. Epithermal gold deposits in volcanic terranes in Gold Metallogeny and Exploration. Ed. R.P/ Foster. Blackie, h. 133-159.

Sillitue, R.H., 1989. Gold deposits in western Pacifi c island arcs: the magmatic connection. In: Geology Monograph 6, The Geology of Gold deposits: The Prospective in 1988: h. 274-291.

Izawa, E., Urashima, Y., Ibaraki, K., Suzuki, R., Yokohama, T., Kawasaki, K., Koga, A., and Taguchi, S., 1990. The Hishikari gold deposit: high grade epithermal veins in Quaternary volcanics of Southern Kyusha, Japan. In Epitehermal gold mienralization of the Circum Pacifi c eds. Hedenquist, White and Siddeley. J. Geochem. Explor. v. 35, No. 1-3, h. 1-56.

Jobson, D.H., Boulter C.A., and Foster, R.P., 1994. Structural control and genesisi of epithermal gold-bearing breccias at Lebong Tandai mine, Western Sumatra, Indonesia. J. Geochem. Explor. V. 50, h. 409-428.

Kastowo, Leo, G.W., Gafoer, S. dan Amin, T.C., 1996. Peta Geologi Lembar Padang Sumatera, skala 1:250.000. Puslitbang Geologi, Bandung.

Katili, J.A., 1973. Volcanism and plate tectonics in the Indonesian Island Arc. Tectonophysics, 26, h. 165-188.

Kavalieris, I., 1986. Geology of Balimbing. C.S.P. Ltd Report (Unpubl.).

Kavalieris, I., Turney, D.J., and Heesterman, I.J., 1987. The geology and mineralization of the Mangani mine, Sumatra, Indonesia. In: Pacific Rim Congress 87. Aust. IMM, Parkville, h. 221-225.

Lawless, J.V., White, P.J., and Bogie, I., 1995. Tectonicfeatures of Sumatra and New Zealand in relation to active and fossil hidrotermal systems: a comparison. Pacrim95. Proceedings International Congress on Earth Science, Exploration and mining around Pacifi c Rim. AIMM., p. 311-1316.

Marcoux, E. and Milesi, J.P., 1994. The epithermal gold deposits in West Java, Indonesia: geology, age and crustal source. In: T.M. van Leeuwen, J.W. Hedenquist, L.P. Jams and J.A.S Dow (eds.). Indonesian Mineral Deposits- Discoveries of the past 25 years, Journ. Geochem. Explor. 50. h. 393-408. Ag- (Mn) deposit of Pongkor (West Java, Indonesia). Indonesia Mining Journal, Vol. 2, No. 3. h. 1-14.

Marcoux, E., Milesi, J.P., Sitorus, T. and Simanjuntak, M., 1996. The epithermal Au-Ag- (Mn) deposit of Pongkor (West Java, Indonesia). Indonesia Mining Journal, Vol. 2, No. 3. h.1-14.

Moore, G.F. and Karig, D.E., 1982. Structural geology of Nias Island, Indonesia: Implications for subduction and tectonics. Amer. J. Sci. 280, p. 193-223.

Morisson, G.W., Rose, W.J., and Jaireth, S., 1990. Geological and gechemical controls on the silver content (fi enness) of gold in gold–silver deposits. Ore Geology Reviews, 6, p. 333-364.

Noble D.C., McCormack, J.K., McKee, E.H., Silberman, M.L., and Wallace, A.B., 1988. Time of mineralization in the evolution of of the McDermitt caldera complex, Nevada-Oregon and teh relation of Middle Miosen mienralization in the nortehrn Great Basin to cueval regional basaltic mamgatic activity. Econ. Geol. 83, p. 859-863.

PT. Robertson Utama Indonesia, 1996. An Introduction to Geothermal Systems: Notes to Accompany Lecture Course in Assosiation with PT Robertson Utama Indonesia, Kingston Morrison Ltd., Jakarta.

Rock, N.M.S., Aldiss, D.T., Aspden, J.A., Clarke, M.C.G., Djunuddin, A., Kartawa, W., Miswar, Thompson, S.J., dan Whandoyo, R., 1983. Peta Geologi Lembar Lubuksikaping, Sumatera, skala 1:250.000. Puslitbang Geologi, Bandung.

Steven, T.A. and Lipman, P.W., 1976. Calderas of the San Juan volcanic fi eld, Southwestern Colorado. US Geol. Surv. Prof. Papper 958, 35h.

Steven., T.A. and Eaton, G.P., 1975. Environment of ore deposition in the Creede mining district, San Juan Mountain, Colorado: Geologic, hydrologic and geophysical setting. Econ. Geol. 70, h.1023-1030.

Tarmizi, S., and Saad, H., 1986. Balimbing gold and silver prospect, Bonjol, West Sumatra, Republic of Indonesia. Indonesian Mining Industry Conference, Paper 22.

Thompson, J.F.H., Abidin, H.Z., Both, R., Martosuroyo, R., Rafferty, W.J. and Thompson, A.J.B, 1994. Alteration and epithermal mineralization in the Masupa Ria volcanic center, Central Kalimantan, Indonesia. In. : T.M. van Leeuwen, J.W. Hedenquist, L.P. James and J.A.S. Dow (editors), Indonesian Mineral Deposits-Discoveries of the Past 25 years. J. Geochem. Explor., 50: 429-455.

Van Bemmelen, R.W., 1949. The Geology of Indonesia. Government Printing Office, The Hague, 732h.

Van Leeuwen, T.M., 1994. 25 Years of mineral exploration and discovery in Indonesia. In. : T.M. van Leeuwen, J.W. Hedenquist, L.P. James and J.A.S.

Dow (editors), Indonesian Mineral Deposits-Discoveries of the Past 25 years. J. Geochem. Explor., 50 : 13-90.

White, N.C. and Hedenquist, J.W., 1990.Epithermal environments and styles of mineralization: Variations and their causes, and guidelines for exploration: J. Geochem. Explor., 36, p. 445-474.

Woods, B.G.M., 1985. The mechanic of progressive deformation in crystal plate: A waning modal from Southeast Asia. Geol. Soc. Malaysia Bull. 18, h. 55-99.

Westeveld, J., 1952. Phases of mountain building and mineral provinces in the East Indies: Internat. Geol. Congr. Report 8th session. Great Britain 1948, Part XIII. H. 245-255.

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