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Journal : Journal of Geoscience, Engineering, Environment, and Technology

The Metamorphic Rocks-Hosted Gold Mineralization At Rumbia Mountains Prospect Area In The Southeastern Arm of Sulawesi Island, Indonesia Hasria, Hasria; Idrus, Arifudin; Warmada, I Wayan
Journal of Geoscience, Engineering, Environment, and Technology Vol 2 No 3 (2017): JGEET Vol 02 No 03 : September (2017)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (963.108 KB) | DOI: 10.24273/jgeet.2017.2.3.434

Abstract

Recently, in Indonesia gold exploration activities  are not only focused along volcanic-magmatic belts, but also starting to shift along metamorphic and sedimentary terrains. The study area is located in Rumbia mountains, Bombana Regency, Southeast Sulawesi Province. This paper is aimed to describe characteristics of alteration and ore mineralization associated  with metamorphic rock-related gold deposits.  The study area is found the placer and  primary gold hosted by metamorphic rocks. The gold is evidently derived from gold-bearing quartz veins hosted by Pompangeo Metamorphic Complex (PMC). These quartz veins are currently recognized in metamorphic rocks at Rumbia Mountains. The quartz veins are mostly sheared/deformed, brecciated, irregular vein, segmented and  relatively massive and crystalline texture with thickness from 1 cm to 15.7 cm. The wallrock are generally weakly altered. Hydrothermal alteration types include sericitization, argillic, inner propylitic, propylitic, carbonization and carbonatization. There some precious metal identified consist of native gold and ore mineralization including pyrite (FeS2), chalcopyrite (CuFeS2), hematite (Fe2O3), cinnabar (HgS), stibnite (Sb2S3) and goethite (FeHO2). The veins contain erratic gold in various grades from below detection limit <0.0002 ppm to 18.4 ppm. Based on those characteristics, it obviously indicates that the primary gold deposit present in the study area is of orogenic gold deposit type. The orogenic gold deposit is one of the new targets for exploration in Indonesia
Geochemical Characteristics of Metamorphic Rock-Hosted Gold Deposit At Onzon-Kanbani Area, Central Myanmar Zar, Aung Tay; Warmada, I Wayan; Setijadji, Lucas Donny; Watanabe, Koichiro
Journal of Geoscience, Engineering, Environment, and Technology Vol 2 No 3 (2017): JGEET Vol 02 No 03 : September (2017)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1682.156 KB) | DOI: 10.24273/jgeet.2017.2.3.410

Abstract

Gold and associated base metal mineralization of Onzon-Kabani area located in the western border of generally N-S trending Mogoke Metamorphic Belt where well-known Sagaing fault is served as a western boundary of this area. In this research area, many artisanal and small-scale gold mines were noted in last three decades. Gold mineralization is hosted in marble and gneiss unit of research area but most common in marble unit. Variety of igneous intrusions are also observed in research area. Mineralizations are observed as fissure filling veins as well as lesser amount of disseminated nature in marble unit. Mineralogically, gold are associated with other base metal such as pyrite, galena, sphalerite, chalcopyrite, marcasite and arsenopyrite. Hydrothermal alteration halos are developed in peripheral of hydrothermal conduits or mineralization veins from proximal to distal such as 1) silicic, 2) sericite-illite, and 3) propylitic alteration.  Most of hydrothermal minerals from each altered zones showed that near neutral condition of pH (e.g. adularia, calcite, illite, sericite and chlorite). Alternatively, hydrothermal alteration zones that show with ore minerals such as native gold, electrum, sphalerite, galena, chalcopyrite, arsenopyrite and marcasite which mostly observed in silicic alteration zone. Typical boiling characters of vein textures and fluid inclusion petrography are observed in hydrothermal system of research area. Boiling, cooling and mixing are possiblily responsible for gold deposition in hydrothermal system. In this paper, authors are documented to clarify the type of mineralization based on hydrothermal alterations, ore and gangue mineral assemblages and fluid inclusion study. All of these data can describe and play an important role for both with respect to understanding deposit genesis and in mineral exploration.
Geochemical Characteristics of Metamorphic Rock-Hosted Gold Deposit At Onzon-Kanbani Area, Central Myanmar Aung Tay Zar; I Wayan Warmada; Lucas Donny Setijadji; Koichiro Watanabe
Journal of Geoscience, Engineering, Environment, and Technology Vol. 2 No. 3 (2017): JGEET Vol 02 No 03 : September (2017)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1682.156 KB) | DOI: 10.24273/jgeet.2017.2.3.410

Abstract

Gold and associated base metal mineralization of Onzon-Kabani area located in the western border of generally N-S trending Mogoke Metamorphic Belt where well-known Sagaing fault is served as a western boundary of this area. In this research area, many artisanal and small-scale gold mines were noted in last three decades. Gold mineralization is hosted in marble and gneiss unit of research area but most common in marble unit. Variety of igneous intrusions are also observed in research area. Mineralizations are observed as fissure filling veins as well as lesser amount of disseminated nature in marble unit. Mineralogically, gold are associated with other base metal such as pyrite, galena, sphalerite, chalcopyrite, marcasite and arsenopyrite. Hydrothermal alteration halos are developed in peripheral of hydrothermal conduits or mineralization veins from proximal to distal such as 1) silicic, 2) sericite-illite, and 3) propylitic alteration. Most of hydrothermal minerals from each altered zones showed that near neutral condition of pH (e.g. adularia, calcite, illite, sericite and chlorite). Alternatively, hydrothermal alteration zones that show with ore minerals such as native gold, electrum, sphalerite, galena, chalcopyrite, arsenopyrite and marcasite which mostly observed in silicic alteration zone. Typical boiling characters of vein textures and fluid inclusion petrography are observed in hydrothermal system of research area. Boiling, cooling and mixing are possiblily responsible for gold deposition in hydrothermal system. In this paper, authors are documented to clarify the type of mineralization based on hydrothermal alterations, ore and gangue mineral assemblages and fluid inclusion study. All of these data can describe and play an important role for both with respect to understanding deposit genesis and in mineral exploration.
The Metamorphic Rocks-Hosted Gold Mineralization At Rumbia Mountains Prospect Area In The Southeastern Arm of Sulawesi Island, Indonesia Hasria Hasria; Arifudin Idrus; I Wayan Warmada
Journal of Geoscience, Engineering, Environment, and Technology Vol. 2 No. 3 (2017): JGEET Vol 02 No 03 : September (2017)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (963.108 KB) | DOI: 10.24273/jgeet.2017.2.3.434

Abstract

Recently, in Indonesia gold exploration activities are not only focused along volcanic-magmatic belts, but also starting to shift along metamorphic and sedimentary terrains. The study area is located in Rumbia mountains, Bombana Regency, Southeast Sulawesi Province. This paper is aimed to describe characteristics of alteration and ore mineralization associated with metamorphic rock-related gold deposits. The study area is found the placer and primary gold hosted by metamorphic rocks. The gold is evidently derived from gold-bearing quartz veins hosted by Pompangeo Metamorphic Complex (PMC). These quartz veins are currently recognized in metamorphic rocks at Rumbia Mountains. The quartz veins are mostly sheared/deformed, brecciated, irregular vein, segmented and relatively massive and crystalline texture with thickness from 1 cm to 15.7 cm. The wallrock are generally weakly altered. Hydrothermal alteration types include sericitization, argillic, inner propylitic, propylitic, carbonization and carbonatization. There some precious metal identified consist of native gold and ore mineralization including pyrite (FeS2), chalcopyrite (CuFeS2), hematite (Fe2O3), cinnabar (HgS), stibnite (Sb2S3) and goethite (FeHO2). The veins contain erratic gold in various grades from below detection limit <0.0002 ppm to 18.4 ppm. Based on those characteristics, it obviously indicates that the primary gold deposit present in the study area is of orogenic gold deposit type. The orogenic gold deposit is one of the new targets for exploration in Indonesia
Ore Forming Fluid of Epithermal Quartz Veins at Cisuru Prospect, Papandayan District, West Java, Indonesia Kha Yay Oo; Wayan Warmada; Anastasia Dewi Titisari; Koichiro Watanabe
Journal of Geoscience, Engineering, Environment, and Technology Vol. 4 No. 3 (2019): JGEET Vol 04 No 03 : September (2019)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (726.877 KB) | DOI: 10.25299/jgeet.2019.4.3.2279

Abstract

The Cisuru area is located in Talegong Sub-district, Garut Regency, West Java, Indonesia which is belongs to the central part of Southern Mountain Slope. The aim of this research is to understand the nature and characteristic of fluid inclusion from quartz veins (especially drill core samples) in the study area. Rock units in the area are characterized by Tertiary volcanic rocks and volcaniclastic sequence which is mainly composed of andesite, andesitic breccia, volcanic breccia, lapilli tuff, dacite and related to the intrusion of diorite. The Cisuru epithermal mineralization is dominantly hosted by andesite, dacite, breccia and lapilli tuff, and would probably be controlled by both permeable rocks and NS and NE-SW trending strike-slip faults. The mineralization is shown as void filling and replacement within the silica zone, veinlets along with the open space/fractures and dissemination. Fluid inclusion from quartz veins was studied to know nature, characteristics and origin of hydrothermal fluids. Microthermometric measurements of fluid inclusions were realized by using a Linkam THMSG 600 combined freezing and heating stages. Homogenization temperature and final ice melting temperature were measured for primary two-phase inclusion from quartz veins. Base on the study of the fluid inclusion, the value of homogenization temperature (Th) range from 200 ºC to 395 °C and ice melting temperature range from -0.1 to - 4.5 where salinity range from 0.2 to 7.2 wt. % NaCl equivalent. Fluid inclusion petrography and microthermometric measurement data exhibit that fluid mixing, dilution and boiling were main processes during the hydrothermal evolution. The formation temperature of each quartz vein is 260 ºC to 290 ºC and also their formation depth is estimated between 560m to 925m respectively. Combination of fluid inclusions petrography, microthermometric measurement, and estimate paleo depth from Cisuru area were suggested under the epithermal environment.
Alteration Alteration, Mineralization and Geochemistry of Metamorphic Rocks Hosted Hydrothermal Gold Deposit at Rumbia Mountains, Bombana Regency, Southeast Sulawesi, Indonesia Hasria Hasria; Arifudin Idrus; I Wayan Warmada
Journal of Geoscience, Engineering, Environment, and Technology Vol. 4 No. 2 (2019): JGEET Vol 04 No 02 : June (2019)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (634.763 KB) | DOI: 10.25299/jgeet.2019.4.2.2346

Abstract

In Indonesia, gold is commonly mined from porphyry, epithermal and skarn type deposits that are commonly found in volcanic/magmatic belts. However, were recently numerous gold prospects discovered in association with metamorphic rocks. This paper is intended to describe an alteration and ore mineralogy hosted by metamorphic rocks at Rumbia mountains, Bombana regency, Southeast Sulawesi province, Indonesia. The study area is found the placer and primary gold hosted by metamorphic rocks. The placer gold is evidently derived from gold-bearing quartz veins hosted by Pompangeo Metamorphic Complex (PMC). This study is conducted in three stages, three stages including desk study, field work and laboratory analysis. Desk study mainly covers literature reviews. Field work includes mapping of surface geology, alteration and ore mineralization as well as sampling of representative rocks types, altered rocks and gold-bearing veins. Laboratory analysis includes the petrologic observation of handspecimen samples, petrographic analysis of the thin section and ore microscopy for polished section, XRD (X-ray diffraction), ICP-AES (Inductively Coupled Plasma Atomic Emission Spectroscopy), ICP-MS (Inductively Coupled Plasma Emission Mass Spectrometry and FA/AAS (Fire Assay/Atomic Absorbtion Spectophotometry) analysis. The results shows that the alteration characteristics of hydrothermal gold deposits in Mendoke and Rumbia mountain consist of 3 (three) alterations namely sericitic, argillic dan propylitic. Characteristics of mineralization hydrothermal gold deposits in the research area are generally p related to gold-bearing quartz veins/veinlets consist of chalcopyrite, pyrite, chrysocolla, covellite, cinnabar, magnetite, hematite and goetite in rocks categorized into greenschist facies. There are three generations of veins identified including the first is parallel to the foliations, the second crosscut the first generation of veins/foliations, and the third is of laminated deformed quartz+calcite veins at the late stage. The quartz veins commonly deformed, segmented, massive, laminated, irregular, brecciated, and occasionally sigmoidal. The veins contain erratic gold in various grades from below detection limit <0.0002 ppm to 18,4000 at found in third generation veins which are laminated quartz±calcite in argillic alteration. ppm. The protoliths of metamorphic rocks in Rumbia Mountain, which comes from sedimentary rocks, spesifically pelitic rocks and graywacke. Based on those characteristics, it obviously indicates that the primary gold deposit present in the study area is of orogenic gold deposits type. The orogenic gold deposit is one of the new targets for exploration in Indonesia.
Geology, Rock Geochemistry and Ore Fluid Characteristics of the Brambang Copper-Gold Porphyry Prospect, Lombok Island, Indonesia. Arifudin Idrus; Aji Syailendra Ubaidillah; I Wayan Warmada; Syafruddin Maula
Journal of Geoscience, Engineering, Environment, and Technology Vol. 6 No. 1 (2021): JGEET Vol 06 No 01 : March (2021)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jgeet.2021.6.1.6145

Abstract

Brambang is one of the porphyry copper-gold prospects/deposits situated along eastern Sunda arc. This study is aimed to understand geological framework, alteration geochemistry and ore fluid characteristics of the prospect. Fieldworks and various laboratory analyses were performed including petrography, ore microscopy, rock geochemistry, chlorite chemistry and fluid inclusion microthermometry. The prospect is composed of andesitic tuff and diorite which are intruded by tonalite porphyries. Tonalite porphyries are interpreted as ore mineralisation-bearing intrusion. Various hydrothermal alterations are identified including potassic, phyllic, propylitic, advanced argillic and argillic types. Ore mineralisation is characterized by magnetite and copper sulfides such as bornite and chalcopyrite. Potassic alteration is typified by secondary biotite, and associated with ore mineralisation. Mass balance calculation indicates SiO2, Fe2O3, K2O, Cu and Au are added during potassic alteration process. Ore forming fluid is dominated by magmatic fluid at high temperature (450-600ºC) and high salinity (60-70 wt. % NaCl eq.). Hydrothermal fluid was diluted by meteoric water incursion at low-moderate temperature of 150-400ºC and salinity of 0.5-7 wt. % NaCl eq.
Geomorphosite Assessment at North Karangsambung -Karangbolong Geopark Kebumen, as Tools of Geotourism Development Chusni Ansori; I. Wayan Warmada; Nugroho Imam Setiawan; Herry Yogaswara
Journal of Geoscience, Engineering, Environment, and Technology Vol. 6 No. 3 (2021): JGEET Vol 06 No 03 : September (2021)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jgeet.2021.6.3.6753

Abstract

Geopark is a sustainable regional development concept that combines geological, biological, and cultural diversity through conservation and education activities to improve the community's welfare. Kebumen Regency has a National Geopark Karangsambung-Karangbolong (GNKK) covering 543,599 Km2 with 41 geosites, ten cultures, and eight biosite since 2018. The northern part of the area is a geological heritage that is widely used for field geological education. The study aims to identify and assess geosites and geomorphosite in the north area, describing the region's geomorphological processes and geological evolution. Field research was conducted to get an overview of geological diversity, geomorphology, and geosite and determine the selected geomorphosite. Geomorphosite assessment is done quantitatively using the Kubalikova method by assessing five main parameters that include; Intrinsic and scientific value, the value of education, economic value, conservation value, and added value. The scientific and intrinsic value of Pentulu Indah (PI) = 4, while Wagirsambeng = 3. Educational value of PI = 4, while Wagirsambeng = 2. Economic value is still not satisfactory, but P.I. = 2, while Wagirsambeng = 1.5. Conservation value of P.I. = 3.5, while Wagirsambeng = 2.5. Added value PI = 2.75 while Wagirsambeng = 1.5. Based on those, geomorphosite Pentulu Indah is 16,26 point or a good value (87.83 %) while Wagirsambeng is 10.5 point or fairly level (56.75 %).
Co-Authors A. Harijoko A. Imai A. Imai A. M. Imran A. W. Yogatama Agung Harijoko Agus Prasetya Ahmad Aminuddin, Muhammad Irman Khalif bin Akira Imai Al-Furqan, Reza Aldian Fahrialam Alvian Rizky Yanuardian Anastasia Dewi Titisari Anita Yuliyanti Anita Yuliyanti Ariffin, Kamar Shah Arifudin Idrus Arifudin Idrus Arifudin Idrus Arifudin Idrus Atmaja, Ammar Dwi Aulia Rahmah Karunianti Aung Tay Zar Aung Tay Zar, Aung Tay Bhakti H. Harahap Bhakti H. Harahap Bunchoeun Pich Chusni Ansori Denizar Rahman Deviana Shinta Maulana Dian Novia Sartika Dian Yesy Fatimah Diyan Aditya Putra Pratama Doni Prakasa Eka Putra Ega Gita Prasastia Endah Retnaningrum Endah Retnaningrum Endang Tri Wahyuni F. Pratiwi Fadlin Fadlin Fadlin Fadlin Fadlin Fadlin Fadlin, Fadlin Franz Michael Meyer Franz Michael Meyer Franz Michael Meyer, Franz Michael Gevor, Even Hakim, Fahmi Haryono, Septiawan Nur Hasria Hasria Hasria Hasria Hasria Hasria, Hasria Herry Yogaswara Heru Hendrayana Hideki, Ohta Himawan Tri Bayu Murti Petrus Hirajima, Tsuyoshi Htun, Tin May I Gde Budi Indrawan I. G. Sukadana I. Nur I. Nur I. Nur Imai, A. Imai, Akira Irzal Nur Irzal Nur, Irzal Iwan Setiawan Jochen Kolb Johan Syafri Mahathir Ahmad Kaharuddin Kaharuddin Kaharuddin, Kaharuddin Kamar Shah Ariffin Kant, Win Kha Yay Oo Khant, Win Koichiro Watanabe Koichiro Watanabe Koichiro Watanabe Koichiro Watanabe Koichiro Watanabe Koichiro Watanabe, Koichiro Kolb, Jochen Kotaro Yonezu Kusumaningrum, Serafica Btari Christiyani Kyaw Linn Zaw Leonardo Anthony Wijaya Lestari Sutra Simamora Linn Zaw, Kyaw Lucas Donny Setijadji Makruf Nurudin Martadiastuti, Vanadia Maulana, Deviana Shinta Mochammad Aziz Mochammad Aziz, Mochammad Mudinillah, Adam Muhamad Ilham Muhammad Irman Khalif bin Ahmad Aminuddin Muhammad Zulfikrie Mutiara Selvina Myo Min Tun Myo Min Tun Myo Min Tun Naing Oo, Toe Nugroho Imam Setiawan Nur, I. Nur, I. Okki Verdiansyah Okki Verdiansyah Okki Verdiansyah Oo, Than Than Pich, Bunchoeun Pramumijoyo, Pranayoga Pramumijoyo, S. Pranayoga Pramumijoyo Prasastia, Ega Gita Putra Pratama, Diyan Aditya Rahman, Denizar Retno Hartati Reza Al-Furqan Riana Listiyastuti Riyadi, Hasan Rodhie Saputra S. Pramumijoyo S. Pramumijoyo Salafudin Salafudin, Salafudin Sang Kompiang Wirawan Saputra, Rodhie Sartika, Dian Novia Seang Sirisokha Septiawan Nur Haryono Sirisokha, Seang Soewondo, Widiasmoro Subagyo Pramumijoyo Subagyo Pramumijoyo, Subagyo Sufriadin, Sufriadin Sukmandaru Prihatmoko Sukmandaru Prihatmoko Syafruddin Maula Syafruddin Maula T. B. Adimedha Takemura, Jiro Tetsuro Yoneda Than Than Oo Tin May Htun Toe Naing Oo Tsuyoshi Hirajima Tsuyoshi Hirajima Tun, Myo Min Ubaidillah, Aji Syailendra Vanadia Martadiastuti Wahyu Wilopo Wawan Budianta Widiasmoro Soewondo Win Kant Win Khant Yoneda, Tetsuro Yonezu, Kotaro Yonezu, Kotaro