Mineralogy, Fluid Characteristics, and Re-Os Age of the Late Triassic Dahu Au-Mo Deposit, Xiaoqinling Region, Central China: Evidence for a Magmatic-Hydrothermal Origin

Abstract

Research Article| January 01, 2015 Mineralogy, Fluid Characteristics, and Re-Os Age of the Late Triassic Dahu Au-Mo Deposit, Xiaoqinling Region, Central China: Evidence for a Magmatic-Hydrothermal Origin Wei Jian; Wei Jian † 1Mineral Resources, Clausthal University of Technology, Adolph-Roemer-Strasse 2A, Clausthal-Zellerfeld 38678, Germany †Corresponding author: e-mail, [e-mail] Search for other works by this author on: GSW Google Scholar Bernd Lehmann; Bernd Lehmann 1Mineral Resources, Clausthal University of Technology, Adolph-Roemer-Strasse 2A, Clausthal-Zellerfeld 38678, Germany Search for other works by this author on: GSW Google Scholar Jingwen Mao; Jingwen Mao 2MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China Search for other works by this author on: GSW Google Scholar Huishou Ye; Huishou Ye 2MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China Search for other works by this author on: GSW Google Scholar Zongyan Li; Zongyan Li 3Jinyuan Mining Industry Co., Ltd, Lingbao 472500, China Search for other works by this author on: GSW Google Scholar Haijiang He; Haijiang He 4Lingbao Gold Investment Co., Ltd, Lingbao 472500, China Search for other works by this author on: GSW Google Scholar Jinge Zhang; Jinge Zhang 3Jinyuan Mining Industry Co., Ltd, Lingbao 472500, China Search for other works by this author on: GSW Google Scholar Hai Zhang; Hai Zhang 3Jinyuan Mining Industry Co., Ltd, Lingbao 472500, China Search for other works by this author on: GSW Google Scholar Jiangwei Feng Jiangwei Feng 3Jinyuan Mining Industry Co., Ltd, Lingbao 472500, China Search for other works by this author on: GSW Google Scholar Author and Article Information Wei Jian † 1Mineral Resources, Clausthal University of Technology, Adolph-Roemer-Strasse 2A, Clausthal-Zellerfeld 38678, Germany Bernd Lehmann 1Mineral Resources, Clausthal University of Technology, Adolph-Roemer-Strasse 2A, Clausthal-Zellerfeld 38678, Germany Jingwen Mao 2MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China Huishou Ye 2MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China Zongyan Li 3Jinyuan Mining Industry Co., Ltd, Lingbao 472500, China Haijiang He 4Lingbao Gold Investment Co., Ltd, Lingbao 472500, China Jinge Zhang 3Jinyuan Mining Industry Co., Ltd, Lingbao 472500, China Hai Zhang 3Jinyuan Mining Industry Co., Ltd, Lingbao 472500, China Jiangwei Feng 3Jinyuan Mining Industry Co., Ltd, Lingbao 472500, China †Corresponding author: e-mail, [e-mail] Publisher: Society of Economic Geologists Received: 14 Dec 2013 Accepted: 04 May 2014 First Online: 09 Mar 2017 Online ISSN: 1554-0774 Print ISSN: 0361-0128 © 2015 Society of Economic Geologists. Economic Geology (2015) 110 (1): 119–145. https://doi.org/10.2113/econgeo.110.1.119 Article history Received: 14 Dec 2013 Accepted: 04 May 2014 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Wei Jian, Bernd Lehmann, Jingwen Mao, Huishou Ye, Zongyan Li, Haijiang He, Jinge Zhang, Hai Zhang, Jiangwei Feng; Mineralogy, Fluid Characteristics, and Re-Os Age of the Late Triassic Dahu Au-Mo Deposit, Xiaoqinling Region, Central China: Evidence for a Magmatic-Hydrothermal Origin. Economic Geology 2015;; 110 (1): 119–145. doi: https://doi.org/10.2113/econgeo.110.1.119 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEconomic Geology Search Advanced Search Abstract The Dahu Au-Mo deposit is located in the Xiaoqinling region and belongs to the Qinling-Dabie orogen of central China. The quartz vein-style Dahu Au-Mo deposit (31 t Au, average grade: 4.7 g/t; 30,000 t Mo, average grade: 0.13 %) formed in four stages, i.e., an early quartz-K-feldspar stage (I), a pyrite-molybdenite stage (II), a sulfide-telluride-sulfosalt-gold stage (III), and a late carbonate-barite stage (IV). Abundant tellurides and sulfosalts occur in stage III: altaite, tellurobismuthite, buckhornite, hessite, petzite, calaverite, aikinite, kupcikite, lindstromite, salzburgite, wittichenite, and tetradymite. The system is characterized by carbono-aqueous fluids of low to moderate salinity and high oxygen fugacity. Total homogenization temperatures of the H2O-CO2 fluid inclusions in stage I and stage III quartz range from 230° to 440°C and 198° to 320°C, respectively. The variation in CO2/H2O ratios and microthermometric data of the H2O-CO2 fluid inclusions results from a combination of fluid unmixing and sequential trapping of fluid inclusions, but also from postentrapment reequilibration. Abundant minerals are present as solid phases in H2O-CO2 fluid inclusions in stage I quartz: Cu1.65S, covellite, chalcopyrite, bornite, molybdenite, pyrite, colusite, anhydrite, and celestine. δ18Oquartz values of stage I quartz range from 10.2 to 12.0‰, with calculated δ18Ofluid values ranging from 5.6 to 7.4‰. The δD values of fluid inclusion waters (thermal decrepitation) in stage I quartz range from −117 to −54‰. The low and scattered δD values reflect a mixture of ore-forming fluids trapped by the H2O-CO2 fluid inclusions at deep crustal levels and postmineralization fluids, possibly meteoric waters, trapped by secondary aqueous fluid inclusions at higher crustal levels during uplift of the Xiaoqinling core complex. Four molybdenite samples yield an Re-Os isochron age of 206.4 ± 3.9 Ma (MSWD = 0.88), suggesting ore formation in the Late Triassic. Metal signature, mineral association, fluid characteristics, and isotope data of the Dahu deposit, together with the tectonomagmatic setting, imply that the ore-forming fluids were derived from an unexposed and oxidized magmatic system, which likely stems from partial melting of enriched lithospheric mantle beneath the North China craton in a postcollisional extensional setting. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.