Minor Elements in Layered Sphalerite as a Record of Fluid Origin, Mixing, and Crystallization in the Navan Zn-Pb Ore Deposit, Ireland

Abstract

Research Article| September 01, 2014 Minor Elements in Layered Sphalerite as a Record of Fluid Origin, Mixing, and Crystallization in the Navan Zn-Pb Ore Deposit, Ireland* D. Gagnevin; D. Gagnevin 1Tullow Oil plc, Number 1, Central Park, Leopardstown, Dublin 18, Ireland Search for other works by this author on: GSW Google Scholar J. F. Menuge; J. F. Menuge † 2UCD School of Geological Sciences, University College Dublin, Belfield, Dublin 4, Ireland †Corresponding author: e-mail, j.f.menuge@ucd.ie Search for other works by this author on: GSW Google Scholar A. Kronz; A. Kronz 3Geowissenschaftliches Zentrum, Georg-August-Universität, D-37077 Göttingen, Germany Search for other works by this author on: GSW Google Scholar C. Barrie; C. Barrie 4Isoprime Ltd, Isoprime House, Earl Road, Cheadle Hulme, Cheadle SK8 6PT, United Kingdom Search for other works by this author on: GSW Google Scholar A. J. Boyce A. J. Boyce 5Scottish Universities Environmental Research Centre, East Kilbride, Glasgow G75 0QF, United Kingdom Search for other works by this author on: GSW Google Scholar Author and Article Information D. Gagnevin 1Tullow Oil plc, Number 1, Central Park, Leopardstown, Dublin 18, Ireland J. F. Menuge † 2UCD School of Geological Sciences, University College Dublin, Belfield, Dublin 4, Ireland A. Kronz 3Geowissenschaftliches Zentrum, Georg-August-Universität, D-37077 Göttingen, Germany C. Barrie 4Isoprime Ltd, Isoprime House, Earl Road, Cheadle Hulme, Cheadle SK8 6PT, United Kingdom A. J. Boyce 5Scottish Universities Environmental Research Centre, East Kilbride, Glasgow G75 0QF, United Kingdom †Corresponding author: e-mail, j.f.menuge@ucd.ie Publisher: Society of Economic Geologists Received: 20 Mar 2013 Accepted: 31 Oct 2013 First Online: 09 Mar 2017 Online ISSN: 1554-0774 Print ISSN: 0361-0128 © 2014 Society of Economic Geologists. Economic Geology (2014) 109 (6): 1513–1528. https://doi.org/10.2113/econgeo.109.6.1513 Article history Received: 20 Mar 2013 Accepted: 31 Oct 2013 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 D. Gagnevin, J. F. Menuge, A. Kronz, C. Barrie, A. J. Boyce; Minor Elements in Layered Sphalerite as a Record of Fluid Origin, Mixing, and Crystallization in the Navan Zn-Pb Ore Deposit, Ireland. Economic Geology 2014;; 109 (6): 1513–1528. doi: https://doi.org/10.2113/econgeo.109.6.1513 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 This study tests the utility of the minor to trace element composition of sphalerite to discriminate between possible sources of ore-forming fluids, and to constrain processes involved in ore genesis of the world-class Irish-type Navan Zn-Pb orebody, Ireland. Detailed petrography and electron microprobe microanalyses were performed on layered sphalerite previously analyzed for Zn, Fe, and S isotope compositions. Layered sphalerite displays a wide range of chemical composition at both sample and crystal scales. The color, style, and scale of layering show variations with chemical composition, but none of these correlations are consistent between samples. However, there are strong intersample correlations between chemical and S-Fe-Zn isotope compositions at the millimeter scale. Sphalerite precipitated from deep, hydrothermal fluids with 34S-enriched sulfide is enriched in Cd, Sb, Cu, and Ag, whereas Fe and As are enriched in sphalerite precipitated from shallow, bacteriogenic brines with isotopically light S. Significant chemical variations also occur at the micrometer scale in sphalerite regardless of its genetic affinity. These variations are interpreted as being due to variations in temperature, pH, and sulfur activity following the arrival at the site of deposition of pulses of hydrothermal fluids at specific stages of sphalerite growth. Therefore the chemistry of sphalerite, coupled with its texture, appears to be a powerful tool to elucidate fluid typing and ore genesis. The results support the hypothesis that layered sphalerite forms by rapid crystallization due to mixing of two fluids of contrasting physicochemical properties, a process required for the formation of Irish-type and some other hydrothermal deposits including, most notably, Mississippi Valley-type (MVT) deposits. The existence of layered sphalerite, coupled with its texture and chemical composition, may therefore provide useful insight for the mineral exploration industry in Ireland and elsewhere. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.