Exhumation-Driven Devolatilization as a Fluid Source for Orogenic Gold Mineralization at the Damang Deposit, Ghana

Abstract

Research Article| June 01, 2015 Exhumation-Driven Devolatilization as a Fluid Source for Orogenic Gold Mineralization at the Damang Deposit, Ghana Alistair J.R. White; Alistair J.R. White † 1Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, United Kingdom OX1 3AN2CSIRO Mineral Resources Flagship, Australian Resources Research Centre, 26 Dick Perry Avenue, Kensington, Western Australia 6151, Australia †Corresponding author: e-mail, [e-mail] Search for other works by this author on: GSW Google Scholar David J. Waters; David J. Waters 1Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, United Kingdom OX1 3AN Search for other works by this author on: GSW Google Scholar Laurence J. Robb Laurence J. Robb 1Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, United Kingdom OX1 3AN Search for other works by this author on: GSW Google Scholar Author and Article Information Alistair J.R. White † 1Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, United Kingdom OX1 3AN2CSIRO Mineral Resources Flagship, Australian Resources Research Centre, 26 Dick Perry Avenue, Kensington, Western Australia 6151, Australia David J. Waters 1Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, United Kingdom OX1 3AN Laurence J. Robb 1Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, United Kingdom OX1 3AN †Corresponding author: e-mail, [e-mail] Publisher: Society of Economic Geologists Received: 24 Jul 2014 Accepted: 19 Oct 2014 First Online: 09 Mar 2017 Online ISSN: 1554-0774 Print ISSN: 0361-0128 © 2015 Society of Economic Geologists. Economic Geology (2015) 110 (4): 1009–1025. https://doi.org/10.2113/econgeo.110.4.1009 Article history Received: 24 Jul 2014 Accepted: 19 Oct 2014 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Alistair J.R. White, David J. Waters, Laurence J. Robb; Exhumation-Driven Devolatilization as a Fluid Source for Orogenic Gold Mineralization at the Damang Deposit, Ghana. Economic Geology 2015;; 110 (4): 1009–1025. doi: https://doi.org/10.2113/econgeo.110.4.1009 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 Gold mineralization at the Damang deposit is unique among currently known orogenic gold deposits in Ghana, comprising gold hosted within metasediments of the Tarkwaian System and contained in a subhorizontal, extensional quartz vein array that formed during regional compression. The Damang region has an extended paragenesis involving numerous structural, metamorphic, igneous, and metasomatic events. Orogenic gold mineralization occurred late in the geologic paragenesis at Damang, postdating regional metamorphism and an earlier episode of hydrothermal alteration, locally termed "pink hematite" alteration, associated with the intrusion of mafic sills and dikes. This earlier pink hematite alteration event involves extensive silicification that changed the rheology of the altered rocks and promoted later fracturing. Following peak regional metamorphism at around 2005 Ma, the Damang region underwent a short period of rapid exhumation, as constrained through numerical thermal modeling of existing pressure-temperature-time data. This exhumation triggered the generation of a subhorizontal fracture array that was fed by fluids released through decompression-driven metamorphic devolatilization. The interaction between these fluids and the host rock resulted in precipitation of gold in association with sulfide-carbonate-potassic alteration halos around quartz veins. Such postpeak metamorphic, exhumation-driven, devolatilization is unlikely to be a singular occurrence and represents a potentially important source of fluid for orogenic gold deposits elsewhere in Ghana, West Africa, and globally. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.