Mineralogy of Hydrothermal Alteration Rocks in Kaligono Region, Kaligesing District, Purworejo Regency, Central Java
Abstract
ABSTRAK
A belt of significant copper-gold mineralization runs through central Java's southern mountains. Kokap, Bagelen, Salaman, and eventually the discovery of porphyry in Sumbersari are all prospective Au-Cu mineralization in Kulonprogo. The research focuses on outcrop observation and laboratory investigation, such as XRD, petrography, and ore microscopy, with the goal of determining the Sumbersari area's mineralogical paragenesis. The research location is located in the Khuluk Gajah part of the old Kulon Progo volcanic complex. The goal of this research is to figure out the mineralogy of the hydrothermally altered rocks in the vicinity. Based on lithology, alteration, and mineralization data gathered from the surface mapping. One of the lithologies obtained is microdiorite, with illite-sericite secondary biotite as the result of megascopic examination of the alteration and Quartz-andesine-albit-serisite-phengitilitklinochlor as the result of XRD analysis. Obtaining crossing veinlets (stockwork) in the forms of "A," "AB"/"B," and "D" veins is also possible. The hydrothermal fluid temperature is in the range of 280 – 320 oC, with a neutral-alkaline pH, based on these mineral correlations (6-7). The Sumbersari sample's hydrothermal alteration reveals a porphyry and epithermal overprint mechanism.
Kata kunci : busur magmatik, Porfiri, alterasi hidrotermal, dan XRD
References
Verdiansyah, Okki. "Studi Desktop untuk Menentukan Mineralisasi Menggunakan Analisis Lineament Density di Pegunungan Kulon Progo, Yogyakarta dan Provinsi Jawa Tengah, Indonesia." Jurnal Geografi Indonesia 51.1 2019: 31-41.
Verdiansyah, Okki, Damas Muharif, and I. Gde Sukadana. Indikasi Mineralisasi Tipe Porfiri di Daerah Sumbersari, Kompleks Pengunungan Kulon Progo, Purworejo, Indonesia. Eksplorium. 2020; 41; 115-128.
Richards, J. P. Postsubduction Porphyry Cu-Au And Epithermal Au Deposits: Products Of Remelting Of Subduction-Modified Lithosphere. Geology.2009; 37(3); 247–250.
G.R., J., … Zientek, M. L. (2013). Porphyry Copper Assessment Of Southeast Asia And Melanesia: U.S. Geological Survey Scientific Investigations Report 2010–5090–D. (Michael L. Zientek, J. M. Hammarstrom, & K. M. Johnson, Ed.). U.S. Geological Survey, Reston, Virginia: 2013
Sillitoe, R. H., & Hedenquist, J. W. Linkage Between Volcanotectonic Setting, Ore-Fluid Composition, And Epithermal Precious Metal Deposits. Society Of Economic Geologists. 2003; 10; 315–343.
Sillitoe, Richard H..Porphyry Copper Systems. England: Society of Economic Geologist. 2010. Inc.
Harjanto A. Vulkanostratigrafi Di Daerah Kulon Progo Dan Sekitarnya, Daerah Istimewa Yogyakarta. MTG. 2014 Jul 17;4(2).
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.
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.
Sillitoe, R. H. “Porphyry Copper Systemsâ€. Economic Geology. 2010; 105, hal. 3– 41
Kingston Morisson, Important Hydrothermal and Their Significance, Seventh Ed., Geothermal and Mineral Services Division, Kingston Morrison Limited, New Zealand, 1997
Arancibia, ON, & Clark, AH. Mineralisasi alterasi magnetit-amphibol-plagioklas awal di deposit tembaga-emas-molibdenum porfiri tembaga Pulau, British Columbia. Geologi Ekonomi, 1996; 91(2), 402–438. doi:10.2113/gsecongeo.91.2.402
Robert A. Ayuso. White Mica Geochemistry of the Catheart Mountain Porphyry Copper Deposit, Maine. U.S. Geological Survey Bulletin. 1987; pp. 7
Corbett, G.J., dan Leach, T.M. Southwest Pasific Rim Gold-Copper Systems: Structure, Alteration, and Mineralization. Colorado: Bookcrafters. 1997; 88.
Reyes, AG (1990). Petrologi sistem panas bumi Filipina dan penerapan mineralogi alterasi untuk penilaian mereka. Jurnal Penelitian Vulkanologi dan Panas Bumi, 43(1-4), 279–309. doi:10.1016/0377-0273(90)90057-m
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