Indikasi Mineralisasi Tipe Porfiri di Daerah Sumbersari, Kompleks Pengunungan Kulon Progo, Purworejo, Indonesia

Okki Verdiansyah, Damas Muharif, I Gde Sukadana

DOI: http://dx.doi.org/10.17146/eksplorium.2020.41.2.5959

Sari


ABSTRAK Pegunungan Kulon Progo merupakan produk magmatisme Busur Sunda-Banda tersusun atas formasi andesit tua. Daerah Sumbersari merupakan bagian dari gunung api Gajah, batuan gunung api tertua Kulon Progo. Indikasi mineralisasi tipe porfiri ditemukan di daerah ini sehingga menarik untuk diteliti lebih lanjut. Penelitian ini bertujuan untuk mengetahui potensi keterdapatan mineral logam berharga (Cu-Au). Metode penelitian yang digunakan adalah pemetaan geologi, analisis petrografi dan mikroskopi bijih, serta analisis geokimia menggunakan XRF dan ICP-MS. Geologi daerah penelitian terletak pada fasies sentral-proksimal Khuluk Gajah, terususun atas intrusi mikrodiorit, mikrodiorit kuarsa, andesit, andesit basaltik-diorit, dan batugamping. Alterasi hidrotermal berkembang pada batuan beku diorit, mikrodiorit, dan sebagian pada andesit. Alterasi hidrotermal dibagi menjadi beberapa kelompok, yaitu ilit-serisit±biotit sekunder, epidot-aktinolit-kalsit±ilit, epidot-kalsit±ilit, dan ilit-serisit±kuarsa. Beberapa fase mineralisasi berkembang, antara lain fase epidot-aktinolit yang diikuti mineralisasi magnetit-kalkopirit, fase biotit-magnetit-kalkopirit-bornit, dan fase akhir serisit-mineral lempung-pirit menggantikan keseluruhan sistem. Analisis geokimia pada batuan teralterasi menunjukan indikasi mineralisasi Cu-Au dengan kadar 491–1447 ppm (0,14%) Cu dan 0,02–0,3 ppm Au dengan rasio elemen Cu:Au adalah 1,01. Karakter geokimia menunjukkan adanya korelasi kuat Cu terhadap Au.

ABSTRACT Kulon Progo Mountain is Sunda-Banda Arc magmatism product composed of an old andesite formation. Sumbersari Area is part of the Gajah volcanic, which is the oldest rock of Kulon Progo volcanics. Indication of porphyry type mineralisation has been found in the area which makes the area interested for further research. The research methodologies are geological mapping, petrography and ore microscopy, and geochemical analysis using XRF and ICP-MS. Geology of the area located in central-proximal facies of Khuluk Gajah, consist of microdiorite, quartz-microdiorite, andesite, basaltic-dioritic andesite intrusions, and limestone. Hydrotermal alteration is developing into certain groups like illite-sericite ± secondary biotite, epidote-actinolite-calcite ± illite, epidot-calcite ± illite, and illite-sericite ± quartz. Some mineralisation phases are developed like epidote-actinolite followed by magnetite-chalcopyrite mineralisation, biotite-magnetite-chalcopyrite-bornite phase and the late phase of sericite-clay-pyrite replacing the entire system. Geochemical analysis on altered rocks show Cu-Au mineralisation indication ranging from 491-1,447 ppm (0.14%) and 0.02-0.3 ppm respectively, with Cu:Au ratio is 1.01. Geochemical characteristic shows strong correlation of Cu to Au.


Kata Kunci


indikasi; mineralisasi; emas; tembaga; tipe porfiri; Kulon Progo

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Referensi


[1] A. Maryono, R. L. Harrison, D. R. Cooke, I. Rompo, dan T. G. Hoschke, “Tectonics and Geology of Porphyry Cu-Au Deposits along the Eastern Sunda Magmatic Arc, Indonesia,” Economic Geology, 113(1), pp. 7–38, 2018, doi: 10.5382/econgeo.2018.4542.

[2] S. Garwin, “District-Scale Expression of Intrusion-Related Hydrothermal Systems near the Batu Hijau Porphyry Copper-Gold Deposit, Sumbawa, Indonesia,” Proceedings of Banda and Eastern Sunda Arcs 2012 MGEI Annual Convention, pp. 133–158, 2012.

[3] A. S. Ubaidillah, A. Idrus, I. W. Warmada, dan S. Maula, “Geokimia pada Endapan Cu-Au Porfiri Brambang Pulau Lombok, Nusa Tenggara Barat, ” Geosapta, 5(2), pp. 103–113, 2019.

[4] R. L. Harrison, A. Maryono, M. S. Norris, dan B. D. Rohrlach, “Geochronology of the Tumpangpitu Porphyry Au-Cu-Mo and High-Sulfidation Epithermal Au-Ag-Cu Deposit : Evidence for Pre- and Postmineralization Diatremes in the Tujuh Bukit District, Southeast Java, Indonesia,” Economic Geology, 113(1), pp. 163–192, 2018, doi: 10.5382/econgeo.2018.4547.

[5] PT Sumbawa Timur Mining, “Mineral Resource Estimate Statement : Hu’u Project, Onto Copper-Gold Deposit, Nusa Tenggara Barat Province – Indonesia,” 2019.

[6] A. Muthi, I. G. Basten, I. G. M. Suasta, dan N. E. W. Litaay, “Characteristics of Alteration and Mineralization at Randu Kuning - Wonogiri Project,” Proceedings of Banda and Eastern Sunda Arcs 2012 MGEI Annual Convention, pp. 117–133, 2012.

[7] L. D. Setijadji, S. Kajino, A. Imai, dan K. Watanabe, “Cenozoic Island Arc Magmatism in Java Island ( Sunda Arc, Indonesia ): Clues on Relationships between Geodynamics of Volcanic Centers and Ore Mineralization,” Resource Geology, 56(3), pp. 267–292, 2008, doi: 10.1111/j.1751-3928.2006.tb00284.x.

[8] A. Harjanto, E. Suparka, S. Asikin, dan Y. S. Yuwono, “Magmatic Related to Hydrothermal Alteration in Kulon Progo, Central Java, Indonesia,” Proceeding International Interdisciplinary Conference Volcano International Gathering, 2006.

[9] S. Prihatmoko dan A. Idrus, “Low-Sulfidation Epithermal Gold Deposits in Java, Indonesia: Characteristics dan Linkage to the Volcano-Tectonic Setting,” Ore Geology Reviews, 121, p. 103490, 2020, doi: 10.1016/j.oregeorev.2020.103490.

[10] D. Pambudi, T. Winarno, dan Y. Aribowo, “Geologi dan Mineralisasi Logam Daerah Sangon, Kokap, Kulon Progo, Daerah Istimewa Yogyakarta,” Jurnal Geosains dan Teknologi, 1(2), 2018, doi: 10.14710/jgt.1.2.2018.74-80.

[11] L. A. Prasetyo, Fadlin, Siswandi, W. T. Anggoro, dan A. Oktaviany, “Pre-Eliminary Study High Sulphidation Epithermal Gold And Possibility Porphyry System in the Southern Part Of Kulonprogo Dome- Hargerejo- Bagelen- Purworejo,” in JCM HAGI-IAGI-IAFMI-IATMI, 2017.

[12] A. Idrus, I. W. Warmada, dan R. I. Putri, “Mineralisasi Emas di Gunung Gupit, Magelang, Jawa Tengah: Sebuah Penemuan Baru Prospek Emas Tipe Ephitermal Sulfidasi Tinggi pada Rangkaian Pegunungan Kulon Progo-Menoreh,” in Annual Engineering Seminar 2013, Yogyakarta, 2013.

[13] O. Verdiansyah, “A Desktop Study to Determine Mineralization Using Lineament Density Analysis at Kulon Progo Mountains, Yogyakarta and Central Java Province, Indonesia,” Indonesian Journal of Geography, 51(1), pp. 31–41, 2019, doi: 0.22146/ijg.37442.

[14] A. Harjanto, “Petrologi dan Geokimia Batuan Volkanik di Daerah Kulonprogo dan sekitarnya Daerah Istimewa Yogyakarta,” Jurnal Ilmiah MTG, 4(1), 2011.

[15] H. G. Hartono, “Peran Paleovolkanisme dalam Tataan Produk Batuan Gunung Api Tersier di Gunung Gajahmungkur, Wonogiri, Jawa Tengah,” Disertasi Doktor, Fakultas Teknologi Mineral, University Padjadjaran, Bandung, 2010.

[16] W. Rahardjo, Sukandarrumidi, dan H. Rosidi, “Yogyakarta Sheet Geological Map scale 1:100.000,” Bandung: Geological Research and Development Center, 1995.

[17] D. H. Barianto, P. Kuncoro, dan K. Watanabe, “The Use of Foraminifera Fossils for Reconstructing the Yogyakarta Graben, Yogyakarta, Indonesia,” Journal of SE Asian Applied Geology, 2(2), pp. 138–143, 2010, doi: 10.22146/jag.7256.

[18] I. Syafri, E. Budiadi, dan A. Sudradjat, “Geotectonic Configuration of Kulon Progo Area, Yogyakarta Konfigurasi Tektonik Daerah Kulon Progo, Yogyakarta,” Indonesian Journal of Geology, 8(4), pp. 185–190, 2013.

[19] R. Hall, B. Clements, H. R. Smyth, dan M. A. Cottam, “A New Interpretation of Java’s Structure,” Indonesian Petroleum Association-31st Annual Convention Proceedings, 2007, doi: 10.29118/ipa.1077.g.035.

[20] S. Husein dan M. Nukman, “Rekonstruksi Tektonik Mikrokontinen Pegunungan Selatan Jawa Timur: Sebuah Hipotesis berdasarkan Analisis Kemagnetan Purba,” Prosiding Seminar Nasional Kebumian ke-8 Jurusan Teknik Geologi FT-UGM, 2015, doi: 10.13140/RG.2.1.3325.5126.

[21] A. Widagdo, S. Pramumijoyo, dan A. Harijoko, “The Morphotectono-Volcanic of Menoreh-Gajah-Ijo Volcanic Rock In Western Side of Yogyakarta-Indonesia,” Journal of Geoscience Engineering Environment and Technology, 3(3), p. 155, 2018, doi: 10.24273/jgeet.2018.3.3.1715.

[22] R. Soeria-Atmadja, R. C. Maury, H. Bellon, H. Pringgoprawiro, M. Polve, dan B. Priadi, “Tertiary Magmatic Belts in Java,” Journal of Southeast Asian Earth Sciences, 9(1–2), pp. 13–27, 1994, doi: 10.1016/0743-9547(94)90062-0.

[23] O. Verdiansyah, “Perubahan Unsur Geokimia Batuan Hasil Alterasi Hidrotermal di Gunung Wungkal, Godean, Yogyakarta,” Kurvatek, 1(1), pp. 59–67, 2016, doi: 10.33579/krvtk.v1i1.198.

[24] O. Verdiansyah, dan H. G. Hartono, “Mineralogy and Geochemistry Analysis of the Igneous Rocks to Strengthen the Hypothesis of Mujil Hill as a Monogenetic Paleo-Volcano,” in Joint Convention Yogyakarta, 2019.

[25] R. W. Le Maitre, A. Streckeisen, B. Zanettin, M. J. Le Bas, B. Bonin, dan P. Bateman, Igneous rocks: A Classification and Glossary of Terms, Recommendations of the International Union of Geological Sciences Subcommission on the Systematics of Igneous Rocks, 2nd ed. New York, United States: Cambridge University Press, 2002, doi: 10.1017/CBO9780511535581.

[26] H. R. Rollinson, Using Geochemical Data: Evaluation, Presentation, Interpretation. London: Routledge, 1993

[27] E. C. Grunsky, “Predicting Archaean Volcanogenic Massive Sulphide Deposit Potential from Lithogeochemistry: Application to the Abitibi Greenstone Belt” Geochemistry: Exploration, Environment, Analysis, 13(4), pp. 317–336, 2013, doi: 10.1144/geochem2012-176.

[28] J. B. Gemmell, “Hydrothermal Alteration Associated with the Gosowong Epithermal Au-Ag deposit, Halmahera, Indonesia: Mineralogy, Geochemistry, and Exploration Implications,” Economic Geology, 102(5), pp. 893–922, 2007, doi: 10.2113/gsecongeo.102.5.893.

[29] Y. Ishikawa, T. Sawaguchi, S. Iwaya, dan M. Horiuchi. “Delineation of Prospecting Targets for Kuroko Deposits based on Modes of Volcanism of Underlying Dacite and Alteration Halos,” Mining Geology, 26, pp. 10–117, 1976, doi: 10.11456/shigenchishitsu1951.26.105.

[30] A. Kishida dan R. Kerrich,“Hydrothermal Alteration Zoning and Gold Concentration at the Kerr- Addison Archean lode Gold Deposit, Kirkland Lake, Ontario (Canada),” Economic Geology, vol. 82, pp. 649–690, 1987, doi: 10.2113/gsecongeo.82.3.649.

[31] M. A.Whitbread dan C. L. Moore, “Two Lithogeochemical Approaches to the Identification of Alteration Patterns at the Elura Zn-Pb-Ag Deposit, Cobar, New South Wales, Australia: Use of Pearce Element Ratio Analysis and Isocon Analysis,” Geochemistry: Exploration, Environment, Analysis, 4(2), pp. 129–141, 2004, doi: 10.1144/1467-7873/03-031.

[32] Y. Saeki dan J. Date, “Computer Application to the Alteration Data of the footwall Dacite Lava at the Ezuri Kuroko Deposits, Akita Prefecture,” Mining Geology, 30(162), pp. 241–250, 1980, doi: 10.11456/shigenchishitsu1951.30.241.

[33] S. Halley, D. Wood, A. Stoltze, J. Godfroid, H. Goswell, dan D. Jack, 2016, “Using Multielement Geochemistry to Map Multiple Components of a Mineral System: Case Study from a Sediment-Hosted Cu-Ni Camp, NW Province, Zambia,” Society of Economic Geologists Newsletter, no. 104, pp. 14–21, 2016.

[34] J. F. Davies dan R. E. Whitehead, “Alkali-Alumina and MgO-Alumina Molar Ratios of Altered and Unaltered Rhyolites,” Exploration and Mining Geology, 15(1), pp. 75–88, 2006, doi: 10.2113/gsemg.15.1-2.75.


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