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Elevated Magmatic Sulfur and Chlorine Contents in Ore-Forming Magmas at the Red Chris Porphyry Cu-Au Deposit, Northern British Columbia, Canada

2018; Volume: 113; Issue: 5 Linguagem: Inglês

10.5382/econgeo.2018.4581

1554-0774

Jing-Jing Zhu, Jeremy P. Richards, Chris J. Rees, Robert A. Creaser, S. Andrew DuFrane, Andrew J. Locock, Joseph A. Petrus, Jürgen Lang,

earthquake and tectonic studies

Research Article| August 01, 2018 Elevated Magmatic Sulfur and Chlorine Contents in Ore-Forming Magmas at the Red Chris Porphyry Cu-Au Deposit, Northern British Columbia, Canada Jing-Jing Zhu; Jing-Jing Zhu 1 State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, PR China2 Harquail School of Earth Sciences, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario, Canada P3E 2C63 Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E3 †Corresponding author: e-mail, jzhu4@laurentian.ca; zhujingjing-1103@163.com Search for other works by this author on: GSW Google Scholar Jeremy P. Richards; Jeremy P. Richards 1 State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, PR China2 Harquail School of Earth Sciences, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario, Canada P3E 2C63 Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E3 Search for other works by this author on: GSW Google Scholar Chris Rees; Chris Rees 4 Imperial Metals Corporation, 200-580 Hornby Street, Vancouver, British Columbia, Canada V6C 3B6 Search for other works by this author on: GSW Google Scholar Robert Creaser; Robert Creaser 3 Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E3 Search for other works by this author on: GSW Google Scholar S. Andrew DuFrane; S. Andrew DuFrane 3 Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E3 Search for other works by this author on: GSW Google Scholar Andrew Locock; Andrew Locock 3 Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E3 Search for other works by this author on: GSW Google Scholar Joseph A. Petrus; Joseph A. Petrus 2 Harquail School of Earth Sciences, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario, Canada P3E 2C6 Search for other works by this author on: GSW Google Scholar Jürgen Lang Jürgen Lang 3 Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E3 Search for other works by this author on: GSW Google Scholar Economic Geology (2018) 113 (5): 1047–1075. https://doi.org/10.5382/econgeo.2018.4581 Article history accepted: 12 Jun 2018 first online: 31 Jul 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation Jing-Jing Zhu, Jeremy P. Richards, Chris Rees, Robert Creaser, S. Andrew DuFrane, Andrew Locock, Joseph A. Petrus, Jürgen Lang; Elevated Magmatic Sulfur and Chlorine Contents in Ore-Forming Magmas at the Red Chris Porphyry Cu-Au Deposit, Northern British Columbia, Canada. Economic Geology 2018;; 113 (5): 1047–1075. doi: https://doi.org/10.5382/econgeo.2018.4581 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter All ContentBy SocietyEconomic Geology Search Advanced Search Abstract The Red Chris porphyry Cu-Au deposit is located in the Stikinia island-arc terrane in northwest British Columbia. It is hosted by the Red Stock, which has five phases of porphyry intrusions: P1, P2E, P2I, P2L, and P3. New U-Pb dating of zircon shows that these intrusions were emplaced over a ~10 m.y. period, with P1 intruded at 211.6 ± 1.3 Ma (MSWD = 0.85), P2I at 206.0 ± 1.2 Ma (MSWD = 1.5), P2L at 203.6 ± 1.8 Ma (MSWD = 1.5), and P3 at 201.7 ± 1.2 Ma (MSWD = 1.05). The ore-forming event at Red Chris was a short-lived event at 206.1 ± 0.5 Ma (MSWD = 0.96; weighted average age of three Re-Os molybdenite analyses), implying a duration of 0.4), indicating that their associated magmas were moderately oxidized. The magmatic water contents estimated from plagioclase and amphibole compositions suggest H2O contents of ~5 wt %. Taken together, the P1 to P3 porphyries are interpreted to be moderately oxidized and hydrous.The porphyry phases are differentiated by sulfur and chlorine contents. The SO3 contents of igneous apatite microphenocrysts from the mineralization-related P2 porphyries are higher (P2E: 0.28 ± 0.10 wt %, n = 19; P2I: 0.32 ± 0.17, n = 15; P2L: 0.29 ± 0.18 wt %, n = 100) than those from the premineralization P1 (0.11 ± 0.03 wt %, n = 34) and postmineralization P3 porphyries (0.03 ± 0.01 wt %, n = 13). The chlorine contents in apatite grains from the P2E, P2I, and P2L porphyries are 1.47 ± 0.22 (n = 19), 0.82 ± 0.10 (n = 15), and 1.47 ± 0.28 wt % (n = 100), also higher than those from P1 (0.51 ± 0.3 wt % Cl, n = 34) and P3 (0.02 ± 0.02 wt % Cl, n = 17). These results imply that the sulfur and chlorine contents of the P2 magmas were higher than in the P1 and P3 magmas, suggesting that elevated magmatic S-Cl contents in the P2 porphyries may have been important for ore formation. Although the process that caused the increase in sulfur and chlorine is not clear, reverse zoning seen in plagioclase phenocrysts from the P2 porphyry, and the occurrence of more mafic compositions in P2L, suggest that recharge of the deeper magma chamber by a relatively S-Cl-rich mafic magma may have triggered the ore-forming hydrothermal event. You do not currently have access to this article.