Helium isotopes as tracers of trapped hydrothermal fluids in ocean-floor sulfides

Abstract

Research Article| September 01, 1994 Helium isotopes as tracers of trapped hydrothermal fluids in ocean-floor sulfides F. M. Stuart; F. M. Stuart 1Department of Geology, Manchester University, Manchester M13 9PL, United Kingdom Search for other works by this author on: GSW Google Scholar G. Turner; G. Turner 1Department of Geology, Manchester University, Manchester M13 9PL, United Kingdom Search for other works by this author on: GSW Google Scholar R. C. Duckworth; R. C. Duckworth 2Department of Geology, University of Wales, Cardiff CF1 3YE, United Kingdom Search for other works by this author on: GSW Google Scholar A. E. Fallick A. E. Fallick 3Isotope Geoscience Unit, Scottish Universities Research and Reactor Centre, East Kilbride G75 0QU, United Kingdom Search for other works by this author on: GSW Google Scholar Geology (1994) 22 (9): 823–826. https://doi.org/10.1130/0091-7613(1994)022<0823:HIATOT>2.3.CO;2 Article history 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 F. M. Stuart, G. Turner, R. C. Duckworth, A. E. Fallick; Helium isotopes as tracers of trapped hydrothermal fluids in ocean-floor sulfides. Geology 1994;; 22 (9): 823–826. doi: https://doi.org/10.1130/0091-7613(1994)022<0823:HIATOT>2.3.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 Helium isotopes have been measured in fluids trapped in minerals from three mid-ocean ridge hydrothermal systems at bare-rock sites and at the sediment-covered site at Middle Valley, northern Juan de Fuca Ridge. Fluid-inclusion 3He/4He ratios from the bare-rock sites are indistinguishable from those of the vent fluids and are close to the local basalt values. Values for δ34S of the host sulfide are consistent with variable contributions of seawater sulfate S to the basalt-derived S in the hydrothermal fluids. This does not affect inclusion-hosted 3He/4He because of the high He concentration of the hydrothermal fluids relative to seawater. Fluid-inclusion 3He/4He ratios from Middle Valley are a mixture of basalt-derived He and radiogenic He acquired from pore fluids in the overlying Pleistocene turbidite sediments after seawater-basalt interaction. The radiogenic He accompanies isotopicalty heavy S, demonstrating that He isotopes may be used to distinguish pore fluids from seawater in hydrothermal systems. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.