The Hydrothermal Breccias Characteristics of The Tumpangpitu Porphyry Cu-Au-High Sulphidation Epithermal Au Prospect, Banyuwangi, East Java, Indonesia

Authors

  • Sutarto Sutarto
  • Sutanto Sutanto
  • Cicih L
  • Hidayat P
  • Khafarel L P
  • Rigenaji P
  • Kenny L

DOI:

https://doi.org/10.31098/ess.v1i1.177

Keywords:

Hydrothermal Breccias, Alteration-Mineralization, Porphyry, H.S. Epithermal Au

Abstract

The research area is administratively located in the Tumpang Pitu Pit Site, Sumberagung Village, Pesanggaran District, Banyuwangi Regency, East Java Province which is included in the coordinate system of the Universal Transfer Mercator (UTM) WGS 84 zone 50S. Compared with phreatomagmatic activity, which is caused by interaction / direct contact between the body of magma and water, phreatic activity releases less energy, and consequently smaller phreatic breccia dimensions. Phreatic breccia or hydrothermal breccias are quite often misinterpreted as phreatomagmatic structures. Hydrothermal breccias are formed in the hydrothermal system, generally at a depth of 200-300 m, and rarely at a depth of 500-1000 m. Based on geological structure analysis, it can be seen on the structure pattern map in the Tumpang Pitu area, there are 2 major faults in the Northwest - Southeast direction. These 2 major faults are the main controller for the formation of minor faults in the Tumpang Pitu area. There is a structural pattern that develops between these 2 major faults, which is a "metallogentically fertile structure" fault or in this pattern mineralization occurs. Based on field observations, core drilling, ASD analysis, and petrographic analysis, the type of alteration based on the mineral assemblage is divided into five, they are quartz, quartz-alunite, quartz kaolinite, kaolinite-montmorillonite-chlorite, and kaolinite-montmorillonite alteration. Mineralization rocks in the study area are volcanic and volcanic clastic rocks and occur as vuggy replacements and stockworks, disseminated, fractures, and veins. Hydrothermal breccias in the Tumpang Pitu area are characterized by enrichment zones of the hydrothermal system with an abundance of sulfides (Goetite, Hematite and Limonite), with Jigsaw and Crackle breccia textures, the mass in the form of sulfide minerals Goetite, Limonite, Hematite, 50-90% silica content and weak to strong vuggy texture. Veins and veinlet that develop are Sugary quartz - sulphide veins (chalcopyrite, bornite) (A Type), sulphide-center line crystalline veins (B Type), pyrite + quartz-chalcopyrite veins (D Type), early biotite (EB Type), High sulfidation epithermal veins (pyrite- bornite-chalcocite-covellite-tetrahedrite-tennatite-enargite) (HSE type), and Magnetite veins (M Type). Assuming homogenisation temperature is identical to formation temperature, the Tumpang Pitu epithermal gold deposit HS is formed at the intermediate temperature 270?C and 310?C. The average melting temperature is -0.3?C and -0.7?C which correspond to the salinity of hydrothermal fluid of 0.5 to 2% by weight equivalent to NaCl. Paleo depths from shallow and deep samples taken were around 650m and 1220m

Author Biography

Sutarto Sutarto

Sutarto, Sutanto, Cicih, L., Hidayat, P., Khafarel L.P., Rigenaji P., and Kenny, L.

References

Abdissalam, R., Bronto, S., Harijoko, A., and Hendratno, A., 2009. Identifikasi Gunung Api Purba Karangtengah di Pegunungan Selatan, Wonogiri, Jawa Tengah, Jurnal Geologi Indonesia, Vol. 4 No. 4 Desember 2009: 253-267.

Achdan, A. and Bahri, 1993. Geological map of the Blambangan Quadrangle, East Java. Geological Research and Developmen Centre, Bandung.

Bemmelen, van, R.W, 1949, The Geology of Indonesia, Vol. IA, Gov. Print. Office, The Hague Martinus Nijhoff

Bronto, S., Mulyaningsing, S., Hartono, G., and Astuti, B., 2008. Gunung Api Purba Watuadeg: Sumber Erupsi dan Posisi Stratigrafi, Jurnal Geologi Indonesia, Vol. 3 No. 3 September 2008: 117-128.

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.

Clarke, 1992, Granitoid Rock. Hall, A., 1987, Igneous Petrology, Longman Scientific & Technical, New York Harland, W. B. dkk, A Geologic Time Scale, Cambridge University Press, New York.

Gafoer, S. and Samodra, H.,1993. Geological Map of Indonesia, Jakarta Sheet, Scale 1:1.000.000, Geological Research and Development Centre, Bandung.

Hamilton,W.B.1979, Tectonics of the Indonesian Region. Professional Paper 1078,U.S. Geolology Survey, Washington, DC.,345 p.

Hartono, G. And Bronto, S., 2007. Asal-usul Pembentukan Gunung Batur di Daerah Wediombo, Gunungkidul, Yogyakarta, Jurnal Geologi Indonesia, Vol. 2 No. 3 September 2007: 143-158. Hellman,P.L., 2010. Tujuh Bukit Project Report on Mineral Resources, Located in East Java,

Indonesia. Technical Report for Interprid Mines Limited.

http://media.wotnews.com.au/esxann/01120850.pdf

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 Geodinamics of Volcanic

Centers and Ore Mineralisation. Resources Geology, vol.56,no.3,267-292.

Paripurno, E.T. and Sutarto., 1996, Studi Petrokimia Magmatisme Tersier Daerah Merubetiri, Jawa Timur, Prosiding pertemuan Ilmiah Tahunan XXV Ikatan Ahli Geologi Indonesia,

Bandung.

Ratman, N., Suwarti, T., and Samodra, H., 1998. Geological Map of Indonesia, Surabaya Sheet,

Second Edition, Scale 1:1.000.000, Geological Research and Development Centre of Indonesia. 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 Geodinamics of Volcanic

Centers and Ore Mineralisation. Resources Geology, vol.56,no.3,267-292.

Setijadji, L.D., and Maryono, A., 2012. Geology and Arc Magmatism of the Eastern Sunda Arc, Indonesia, Proceeding of Banda and Eastern Sunda Arcs 2012 MGEI Annual Convention, 26-

November 2012, Malang, East Java, Indonesia, p.1-22.

Sapei T., Suganda, A.H., Astadiredja,K.A.S., and Suharsono, 1992, Geological map of the Jember

Quadrangle, East Java. Geological Research and Developmen Centre, Bandung. Soeria-Atmadja, R., Maury,R.C., Bellon,H., Pringgoprawiro,H., Polvé,M., and Priadi,B., 1991, The Teriary Magmatic Belt in Java, The Procceding of the Silver Jubbiles Symposium On the

Dynamics of Subduction and Its Products,Yogyakarta: 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 Sukmandaru Prihatmoko1, Sumardiman Digdowirogo2 , dan Damar Kusumanto, 2005, 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.

Sutanto dkk, 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.

Sutarto, Sutanto, and Salatun Said, 2002 Mineralisasi logam pada busur magmatik Jawa, Buletin

Wimaya, UPN Pres Yogyakarta.

Sutarto, Idrus, A., Harijoko, A., Setijadji, L.,D., and Meyer, F.M. 2015. Veins and Hydrothermal

Breccias of The Randu Kuning Porphyry Cu-Au and Epithermal Au Deposits at Selogiri Area,

Central Java, Indonesia. J.SE Asian App.Geol, 2015, Vol 7(2) pp. 80-99 ISSN 2086-5104. Wilson, M., 1989, Igneous Petrogenesis, A Global Tectonic Approach, Unwin Hyman, London Sillitoe, R.H., 1994., Indonesian mineral deposits – intruductory comments, comparisons and

speculations., Journal of Geochemical Exploration, vol. 50., pp 1-11.

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2020-10-27

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