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GEOREF RECORD

Fluid mixing during ore deposition at the Tynagh base-metal deposit, Ireland

David A. Banks and Michael J. Russell
Fluid mixing during ore deposition at the Tynagh base-metal deposit, Ireland (in Proceedings of the Eleventh European symposium on Fluid inclusions research (ECROFI XI), Benedetto De Vivo (editor) and Pierfranco Lattanzi (editor))
European Journal of Mineralogy (October 1992) 4 (5): 921-931

Abstract

This deposit is hosted by Upper Tournaisian to Lower Visean age Waulsortian carbonates in W Ireland. Epigenetic galena, sphalerite and baryte are located in the hanging wall of a major normal fault. Fluid inclusions in quartz, sphalerite and baryte show that two distinct fluids were responsible for the mineralization. A high-T moderate-salinity fluid (240 degrees C, 12 wt.%), derived from convection of Carboniferous sea-water in the crust, carried most of the ore metals. A low-T high-salinity fluid (< 70 degrees C, 21 wt.%), lying on or close to the sea-floor, provided most of the reduced S and sulphate. These fluids mixed a little on the sea- floor as well as in the epigenetic ore zones and in the fault zone, which acted as a major conduit for both ascending and descending fluids. Post-ore fluid inclusions in calcite show no evidence of the high T fluid but record that the high salinity was being progressively diluted by a low salinity (approx 1 wt.%) SO (super 2-) (sub 4) or HCO (super -) (sub 3) meteoric fluid. The results are similar to those from the Silvermines deposit and suggest that other Irish base-metal deposits may have been derived from similar fluids.


ISSN: 0935-1221
Serial Title: European Journal of Mineralogy
Serial Volume: 4
Serial Issue: 5
Title: Fluid mixing during ore deposition at the Tynagh base-metal deposit, Ireland
Title: Proceedings of the Eleventh European symposium on Fluid inclusions research (ECROFI XI)
Author(s): Banks, David A.Russell, Michael J.
Author(s): De Vivo, Benedettoeditor
Author(s): Lattanzi, Pierfrancoeditor
Affiliation: University of Glasgow, Department of Geology and Applied Geology, Glasgow, United Kingdom
Affiliation: Dipartimento di Geofisica e Vulcanologia, Naples, Italy
Pages: 921-931
Published: 199210
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Federal Republic of Germany
Meeting name: Eleventh European symposium on Fluid inclusion research
Meeting location: Florence, ITA, Italy
Meeting date: 19910410April 10-12, 1991
References: 38
Accession Number: 1995-056272
Categories: Economic geology, geology of ore deposits
Document Type: Serial Conference document
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table, geol. sketch map
N53°08'60" - N53°08'60", E08°22'00" - E08°22'00"
Secondary Affiliation: Universita di Firenze, ITA, ItalyUniversity of Leeds, GBR, United Kingdom
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United KingdomTwickenhamUKUnited Kingdom
Update Code: 199520
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