Reduced porphyry copper-gold deposits: A new variation on an old theme

Research Article| June 01, 2000 Reduced porphyry copper-gold deposits: A new variation on an old theme Stephen M. Rowins Stephen M. Rowins 1Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information Stephen M. Rowins 1Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada Publisher: Geological Society of America Received: 25 Oct 1999 Revision Received: 01 Mar 2000 Accepted: 09 Mar 2000 First Online: 02 Jun 2017 Online Issn: 1943-2682 Print Issn: 0091-7613 Geological Society of America Geology (2000) 28 (6): 491–494. https://doi.org/10.1130/0091-7613(2000)28<491:RPCDAN>2.0.CO;2 Article history Received: 25 Oct 1999 Revision Received: 01 Mar 2000 Accepted: 09 Mar 2000 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Stephen M. Rowins; Reduced porphyry copper-gold deposits: A new variation on an old theme. Geology 2000;; 28 (6): 491–494. doi: https://doi.org/10.1130/0091-7613(2000)28<491:RPCDAN>2.0.CO;2 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 SocietyGeology Search Advanced Search Abstract It is a widely accepted fact that porphyry Cu-Au deposits form from highly oxidized ore fluids. Despite this assertion, several otherwise typical porphyry Cu-Au deposits exhibit clear evidence of having formed from relatively reduced ore fluids. These "reduced" porphyry Cu-Au deposits lack primary hematite, magnetite, and sulfate minerals (i.e., anhydrite), but contain abundant hypogene pyrrhotite, commonly have carbonic-rich ore fluids with substantial CH4, and are associated with ilmenite-bearing, reduced I-type granitoids. Based on a synthesis of theoretical, experimental, and field data, a variation on the classic porphyry Cu model is proposed to explain the formation of reduced porphyry Cu-Au deposits and their relatively Cu-poor but Au-rich nature. The proposed reduced porphyry Cu-Au model does not contradict the current understanding of porphyry Cu-Au formation. Rather, it adds yet another variation on the theme of porphyry Cu-Au genesis. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.