Zonation of Merensky-Style Platinum-Group Element Mineralization in Turfspruit Thick Reef Facies (Northern Limb of the Bushveld Complex)*

Abstract

Research Article| September 01, 2017 Zonation of Merensky-Style Platinum-Group Element Mineralization in Turfspruit Thick Reef Facies (Northern Limb of the Bushveld Complex)* Marina A. Yudovskaya; Marina A. Yudovskaya † 1Economic Geology Research Institute, School of Geosciences, University of Witwatersrand, Wits 2050, South Africa2Institute of Geology of Ore Deposits, Mineralogy, Petrography and Geochemistry RAS, Staromonetny 35, Moscow 119017, Russia †Corresponding author: e-mail, marina.yudovskaya@wits.ac.za. Search for other works by this author on: GSW Google Scholar Judith A. Kinnaird; Judith A. Kinnaird 1Economic Geology Research Institute, School of Geosciences, University of Witwatersrand, Wits 2050, South Africa Search for other works by this author on: GSW Google Scholar Danie F. Grobler; Danie F. Grobler 3Exploration & Geology, Ivanplats (Pty.) Ltd., Mokopane, South Africa Search for other works by this author on: GSW Google Scholar Gelu Costin; Gelu Costin 4Department of Earth Science, Rice University, 6100 Main Street, Houston, Texas 77005 Search for other works by this author on: GSW Google Scholar Vera D. Abramova; Vera D. Abramova 2Institute of Geology of Ore Deposits, Mineralogy, Petrography and Geochemistry RAS, Staromonetny 35, Moscow 119017, Russia Search for other works by this author on: GSW Google Scholar Tim Dunnett; Tim Dunnett 3Exploration & Geology, Ivanplats (Pty.) Ltd., Mokopane, South Africa Search for other works by this author on: GSW Google Scholar Sarah-Jane Barnes Sarah-Jane Barnes 5Sciences de la Terre, Université du Québec à Chicoutimi, Québec G7H 2B1, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information Marina A. Yudovskaya † 1Economic Geology Research Institute, School of Geosciences, University of Witwatersrand, Wits 2050, South Africa2Institute of Geology of Ore Deposits, Mineralogy, Petrography and Geochemistry RAS, Staromonetny 35, Moscow 119017, Russia Judith A. Kinnaird 1Economic Geology Research Institute, School of Geosciences, University of Witwatersrand, Wits 2050, South Africa Danie F. Grobler 3Exploration & Geology, Ivanplats (Pty.) Ltd., Mokopane, South Africa Gelu Costin 4Department of Earth Science, Rice University, 6100 Main Street, Houston, Texas 77005 Vera D. Abramova 2Institute of Geology of Ore Deposits, Mineralogy, Petrography and Geochemistry RAS, Staromonetny 35, Moscow 119017, Russia Tim Dunnett 3Exploration & Geology, Ivanplats (Pty.) Ltd., Mokopane, South Africa Sarah-Jane Barnes 5Sciences de la Terre, Université du Québec à Chicoutimi, Québec G7H 2B1, Canada †Corresponding author: e-mail, marina.yudovskaya@wits.ac.za. Publisher: Society of Economic Geologists Accepted: 20 Apr 2017 First Online: 25 Aug 2017 Online Issn: 1554-0774 Print Issn: 0361-0128 © 2017 Society of Economic Geologists.Society of Economic Geologists Economic Geology (2017) 112 (6): 1333–1365. https://doi.org/10.5382/econgeo.2017.4512 Article history Accepted: 20 Apr 2017 First Online: 25 Aug 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Marina A. Yudovskaya, Judith A. Kinnaird, Danie F. Grobler, Gelu Costin, Vera D. Abramova, Tim Dunnett, Sarah-Jane Barnes; Zonation of Merensky-Style Platinum-Group Element Mineralization in Turfspruit Thick Reef Facies (Northern Limb of the Bushveld Complex). Economic Geology 2017;; 112 (6): 1333–1365. doi: https://doi.org/10.5382/econgeo.2017.4512 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 stratigraphy, whole-rock composition, and mineralogy from a thick undisturbed section of the Platreef at depth on Turfspruit in the northern limb of the Bushveld Complex have been examined in detail. This section has much more in common with the Critical zone than with the Platreef structure updip although the high-grade platinum-group element (PGE) reefs, located close to the boundary with the Main zone, are much thicker than any known Merensky reef facies. A key feature that marks the conversion of the Platreefstyle mineralization into the Merensky style is the regular appearance of chromite seams, which become more persistent with decreasing contamination westward and downdip. The similar zonal distribution of platinum-group minerals (PGM) in two consecutive thick PGE reefs correlates with changes in silicate compositions and vertical zonation of PGE concentrations in whole rocks and base metal sulfides. This supports orthomagmatic in situ crystallization of ore minerals during mixing of consecutive magmatic influxes. The typical Merensky-style ore assemblages of predominant Pt sulfides and alloys are developed within ~1-m-thick intervals, which correspond to the highest temperature mixing zones between two magmas, whereas the rest of the reefs host Pt-Pd bismuthotellurides and arsenides. PGE content and tenor, as well as Cu/Pd in major base metal sulfides in the Turfspruit reefs, are within the range of the typical high-grade Merensky values, suggesting the same enrichment process. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.