TY - JOUR
T1 - The Age and Origin of the Ruwai Polymetallic Skarn Deposit, Indonesia
T2 - Evidence of Cretaceous Mineralization in the Central Borneo Metallogenic Belt
AU - Dana, Cendi D.P.
AU - Agangi, Andrea
AU - Idrus, Arifudin
AU - Chelle-Michou, Cyril
AU - Lai, Chun Kit
AU - Ishida, Mizuki
AU - Guillong, Marcel
AU - González-Álvarez, Ignacio
AU - Takahashi, Ryohei
AU - Yano, Moei
AU - Mimura, Kazuhide
AU - Ohta, Junichiro
AU - Kato, Yasuhiro
AU - Simbolon, Doly R.
AU - Xia, Xiao Ping
N1 - Funding Information:
1School of GeoSciences, Grant Institute, The University of Edinburgh, Edinburgh EH9 3FE, United Kingdom 2Graduate School of International Resource Sciences, Akita University, Akita 010-0852, Japan 3Department of Geological Engineering, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia 4Department of Earth Sciences, ETH Zurich, Zurich 8092, Switzerland 5Global Project Generation and Targeting, Fortescue Metals Group Ltd., East Perth, Western Australia 6004, Australia 6Faculty of Science, Universiti Brunei Darussalam, BE 1410 Gadong, Brunei Darussalam 7Department of Systems Innovation, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan 8Commonwealth Scientific and Industrial Research Organisation (CSIRO), Mineral Resources, Discovery Program, Perth, Western Australia 6151, Australia 9University of Western Australia, Centre for Exploration Targeting, Perth, Western Australia 6009, Australia 10Ocean Resources Research Center for Next Generation, Chiba Institute of Technology, Chiba 275-0016, Japan
Publisher Copyright:
© 2023 Society of Economic Geologists, Inc. All rights reserved.
PY - 2023/9
Y1 - 2023/9
N2 - The Ruwai skarn deposit is the largest polymetallic skarn deposit in Borneo and is located in the Schwaner Mountains. The skarns and massive orebodies are hosted in marble of the Jurassic Ketapang Complex, which was intruded by Cretaceous Sukadana granitoids. The prograde-stage garnet and retrograde-stage titanite yielded U-Pb ages of 97.0 ± 1.8 to 94.2 ± 10.3 Ma and 96.0 ± 2.9 to 95.0 ± 2.0 Ma, respectively. These ages are similar to Re-Os ages obtained on sulfides (96.0 ± 2.3 Ma) and magnetite (99.3 ± 3.6 Ma). The U-Pb zircon ages reveal that magmatism at Ruwai occurred in three phases, including the Early Cretaceous (ca. 145.7 and 106.7–105.7 Ma; andesite-dacite), Late Cretaceous (ca. 99.7–97.1 Ma; diorite-granodiorite), and late Miocene (ca. 10.94–9.51 Ma; diorite-dolerite). Based on geochemical and stable isotopic data (C-O-S) the Ruwai skarn ores are interpreted to have formed from oxidized fluids at ca. 160 to 670°C. The ore-forming fluids and metals were mostly magmatic in origin but with significant crustal input. Ruwai skarn mineralization occurred in the Late Cretaceous, associated with Paleo-Pacific subduction beneath Sundaland after the Southwest Borneo accretion. Ruwai is the first occurrence of Cretaceous mineralization recognized in the Central Borneo metallogenic belt.
AB - The Ruwai skarn deposit is the largest polymetallic skarn deposit in Borneo and is located in the Schwaner Mountains. The skarns and massive orebodies are hosted in marble of the Jurassic Ketapang Complex, which was intruded by Cretaceous Sukadana granitoids. The prograde-stage garnet and retrograde-stage titanite yielded U-Pb ages of 97.0 ± 1.8 to 94.2 ± 10.3 Ma and 96.0 ± 2.9 to 95.0 ± 2.0 Ma, respectively. These ages are similar to Re-Os ages obtained on sulfides (96.0 ± 2.3 Ma) and magnetite (99.3 ± 3.6 Ma). The U-Pb zircon ages reveal that magmatism at Ruwai occurred in three phases, including the Early Cretaceous (ca. 145.7 and 106.7–105.7 Ma; andesite-dacite), Late Cretaceous (ca. 99.7–97.1 Ma; diorite-granodiorite), and late Miocene (ca. 10.94–9.51 Ma; diorite-dolerite). Based on geochemical and stable isotopic data (C-O-S) the Ruwai skarn ores are interpreted to have formed from oxidized fluids at ca. 160 to 670°C. The ore-forming fluids and metals were mostly magmatic in origin but with significant crustal input. Ruwai skarn mineralization occurred in the Late Cretaceous, associated with Paleo-Pacific subduction beneath Sundaland after the Southwest Borneo accretion. Ruwai is the first occurrence of Cretaceous mineralization recognized in the Central Borneo metallogenic belt.
UR - http://www.scopus.com/inward/record.url?scp=85173135806&partnerID=8YFLogxK
U2 - 10.5382/econgeo.5009
DO - 10.5382/econgeo.5009
M3 - Article
AN - SCOPUS:85173135806
SN - 0361-0128
VL - 118
SP - 1341
EP - 1370
JO - Economic Geology
JF - Economic Geology
IS - 6
ER -