HYDROTHERMAL ALTERATION AND VEIN TYPES OF THE RANDU KUNING PORPHYRY Cu-Au DEPOSIT AT SELOGIRI AREA, WONOGIRI

  • Sutarto Sutarto Universitas Pembangunan Nasional “Veteran” Yogyakarta
  • Arifudin Idrus
  • Sapto Putranto
  • Agung Harjoko
  • Lucas D Setijadji
  • Franz M Meyer
  • Rama Danny
Keywords: paragenetic sequence, porphyry, veins.

Abstract

Many Tertiary hydrothermal altered dioritic composition intrusive rocks were found at the Randu Kuning area and its vicinity, Selogiri, including hornblende microdiorite, hornblende-pyroxene diorite and quartz diorite. The hydrothermal fluids which responsible for the alteration and mineralization at the area is associated with the occurence of the horblende microdiorite intrusion. The alteration zone at the Randu Kuning area and its vicinity can be divided into
several hydrothermal alteration zones, such as potassic (magnetite-biotite-K feldspar), prophyllitic (chlorite-magnetite-epidote-carbonate), phyllic (quartz-sericite-chlorite) and argillic (clay mineral-sericite). The alteration pattern in the Randu Kuning porphyry Cu-Au deposit is tipically a diorite model characterising by the domination of potassic alteration and prophyllitic zone. Phyllic and argillic alteration types are restrictive found within the fault zones. A lot of porphyry vein types were found and observed at the Randu Kuning area, and classified into at least seven vein types. The paragenetic sequence of those veins from the
earliest to the latest respectively are 1). Magnetite-chalcopyrite±quartz-biotite veinlets, 2). Quartz±magnetite (A type) veins, 3). Banded/Laminated quartz-magnetite (M type) veins, 4). Quartz±K feldspar (B type)veins, 5). Quartz with thin centre line sulphide (AB type) veins, 6). Pyrite±chalcopyrite (C type) veinlets, and 7). Pyrite-quartz+chalcopyrire+carbonate (D type) veins. Gold and copper mineralisation of the Randu Kuning Porphyry Cu-Au deposit, mostly related to the presence of quartz veins/veinlets containing sulfide i.e. Quartz with thin centre line sulphide veins, Pyrite±chalcopyrite veinlets, and Pyrite-quartz+chalcopyrire+carbonate veins.

References

Bemmellen, van, R.W, 1949, The Geology of Indonesia, and Adjacent Archipelagoes, Vol. IA, Gov. Print. Office, Martinus Nijhoff, the Hague.

Carlile, J.C. dan Mitchell, A.H.G., 1994, Magmatic Arcs and Associated Gold and Copper Mineralisation in Indonesia, Journal of Geochemical Exploration, Elsevier Science,Amsterdam, 50: 92-142.

Corbett, G., 2011, Comments on The Exploration Potential of The Wonogiri Porphyry Cu-Au Project, Central Java, Indonesia, Corbett Geological Services Pty. Ltd., Unpublished,27 p.

Corbett, G., 2012, Further Comments on The Wonogiri Porphyry Cu-Au Project Central Java, Indonesia, Corbett Geological Services Pty. Ltd., Unpublished, 37 p.

Corbett, G., and Leach, T.M.,1996, Southwest Pacific Rim Gold Copper Systems: Structure, Alteration, and Mineralization, Workshop Manual for Exploration Workshop presented at Jakarta August 1996, 186 p.

Gustafson, L.B. dan Hunt, J.P. 1975, The Porphyry Copper Deposit at El Salvador, Chile, Economic Geology, v 70:pp. 857-912.

Hartono, G., 2010, The Role of Paleovolcanism in The Tertiary Volcanic Rock Product Setting at Gajahmungkur Mt., Wonogiri, Central Java, Dissertatio in UNPAD, Unpublished, 190 p.

Idrus, A., 2008, Transport and Deposition of Copper and Gold in Porphyry Deposit: A Constraint From Microthermometry and Hydrothermal Biotite Chemistry, Media Teknik No.3 Tahun XXX Edisi Agustus 2008 ISSN 0216-3012 p.276-283.

Imai, A., Shinomiya, J., Soe, M.T., Setijadji, L.D., Watanabe, K., and Warmada, I.W., 2007, Porphyry-Type Mineralization at Selogiri Area, Wonogiri Regency, Central Java, Indonesia, Resources Geology, vol.57, no. 2:230-240.

Isnawan, D., Sukandarrumidi and Sudarno, I., 2002, Kontrol Struktur Geologi Terhadap Jebakan Tembaga Sebagai Arahan Eksploitasi di Daerah Ngerjo dan Sekitarnya Kecamatan Tirtomoyo, Kabupaten Wonogiri Propinsi Jawa Tengah, Gama Sains IV (2) Juli 2002, p.149-157.

Katili, J. A., 1989, Evolution of the Southeast Asian arc complex, Geol. Indon. Jakarta, 12:113-143. Leeuwen, van, T.M., 1994, 25 Years of Mineral Exploration and Discovery in Indonesia, Jornal of Geochemical Exploration, Elsevier Science, Amsterdam, 50: 13-89.

Maryono, A., Setijadji, L.D., Arif, J., Harrison, R., Soeriaatmadja, E., 2012, Gold, Silver and Copper Metallogeny of the Eastern Sunda Magmatic Arc Indonesia, Proceeding of Banda and Eastern Sunda Arcs 2012 MGEI Annual Convention, 26-27 November 2012, Malang, East Java, Indonesia, p.23-38.

Muthi, A., Basten, I.G., Suasta, I.G.M., and Litaay, N.E.W., 2012, Characteristic of Alteration and Mineralization at Randu Kuning-Wonogiri Project, Proceeding of Banda and Eastern Sunda Arcs 2012 MGEI Annual Convention, 26-27 November 2012, Malang, East Java, Indonesia, p. 117-132.

Pirajno F., 1992, Hydrothermal Mineral deposits, Principles and Fundamental Concepts for the Exploration Geologist, Springer-Verlag, Berlin, Heidelberg, New York, London, Paris, 709 p. Pirajno, F., 2009, Hydrothermal Processes and Mineral Systems, Springer-Geological Survey of Western Australia, 1250 p.

Setijadji, L.D., Kajino, S., Imai, A., and Watanabe, K., 2006, Cenozoic Island Arc Magmatism in Java Island (Sunda Arc, Indonesia): Clues on Relationships between Geodynamics of Volcanic Centers and Ore Mineralization, Resources Geology, vol.56, no.3,267-292.

Sillitoe, R.H., 2010, Porphyry Copper System, Economic Geology v.105, pp.3-41, 2010.

Smyth, H.L., Hall, R. and Nichols, G., 2008, Cenozoic Volcanic Arch History of East Java Indonesia: The Stratigraphic Record of Eruption on An Active Continental Margin, The Geological Society of America Special Paper No. 436, p. 199-221.

Soeria-Atmadja, R., Maury,R.C., Bellon,H., Pringgoprawiro,H., Polvé,M., and Priadi,B., 1991,The Teriary Magmatic Belt in Java, Proceeding of the Silver Jubilee Symposium On the Dynamics of Subduction and Its Products,Yogyakarta: p. 98-121.

Soeria-Atmadja, R., Maury,R.C., Bellon,H., Pringgoprawiro,H., Polvé,M., and Priadi,B., 1993, Tertiary Magmatic Belt in Java, Journal of Southeast Asian Earth Science, 9, 13-27.

Suasta, I.G.M and Sinugroho, I.A., 2011, Occurrence of Zoned Epithermal to Porphyry Type Cu-Au Mineralization at Wonogiri, Central Java, Proceeding of The 36th HAGI and 40th IAGI Annual Convention.

Surono, Toha, B., and Sudarno, I., 1992, Geological map of the Surakarta-Giritontro Quadrangles, Java, Geological Research and Development Centre, Bandung.

Sutanto, Soeria-Atmadja, R., Maury,R.C., and Bellon,H., 1994, Geochronology of Tertiary Volcanism in Java, Prosiding Seminar Geologi dan Geotektonik Pulau Jawa Sejak Akhir Mesosoik Hingga Kuarter, Jurusan Teknik Geologi, Universitas Gajahmada, Yogyakarta, p.53-56.

Sutarto, Idrus, A., Putranto, S., Harjoko, A., Setijadji, L.D., Meyer, M., and Danny, R., 2013, Magmatism and Porphyry Cu-Au Mineralisation at The Randu Kuning Prospect, Selogiri Area, Central Java. Prosiding Seminar Kebumian VIII FTM UPN “Veteran”

Yogyakarta.

Sutarto, Idrus, A., Putranto, S., Harijoko,A., Setijadji,L.D., Meyer, F.M, and Danny, R. 2013, Veining Paragenetic Sequence of The Randu Kuning Porphyry Cu-Au Deposit at Selogiri Area, Central Java. Extended Abstract: CD Proceeding of The 38th HAGI and 42nd IAGI Annual Convention and Exibition Medan, 28-31 October 2013.

Sutarto, Idrus,A., Meyer, M., Harijoko,A., Setijadji,L.D., , and Danny, R. 2013, The Dioritic Alteraation Model of The Randu Kuning Porphyry Cu-Au, Selogiri Area, Central Java. Proceedings International Conference on Georesources and Geological Engineering, December 11-12, 2013 Yogyakarta, ISBN 978-602-14066-5-6. p.122-132.

Prihatmoko, S., Digdowirogo, S., and Kusumanto, D., 2002, Potensi Cebakan Mineral di Jawa Tengah dan Daerah Istimewa Yogyakarta. Prosiding Seminar Geologi Jawa Tengah dan Daerah Istimewa Yogyakarta, Ikatan Ahli Geologi Indonesia Pengda Yogyakarta, p. 87-108.

Published
2014-05-08
Section
Buletin Sumber Daya Geologi