Fluid evolution in base-metal sulphide mineral deposits in the metamorphic basement rocks of southwest Scotland and Northern Ireland

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doi: 10.1002/gj.973
Authors:Baron, Martin; Parnell, John
Author Affiliations:Primary:
University of Aberdeen, Department of Geology and Petroleum Geology, Aberdeen, United Kingdom
Volume Title:Geological Journal
Source:Geological Journal, 40(1), p.3-21. Publisher: Wiley & Sons, Chichester, United Kingdom. ISSN: 0072-1050
Publication Date:2005
Note:In English. 46 refs.; illus., incl. 1 table, geol. sketch map
Summary:The Dalradian and Ordovician-Silurian metamorphic basement rocks of southwest Scotland and Northern Ireland host a number of base-metal sulphide-bearing vein deposits associated with kilometre-scale fracture systems. Fluid inclusion microthermometric analysis reveals two distinct fluid types are present at more than half of these deposits. The first is an H2O-CO2-salt fluid, which was probably derived from devolatilization reactions during Caledonian metamorphism. This stage of mineralization in Dalradian rocks was associated with base-metal deposition and occurred at temperatures between 220 and 360°C and pressures of between 1.6 and 1.9 kbar. Caledonian mineralization in Ordovician-Silurian metamorphic rocks occurred at temperatures between 300 and 360°C and pressures between 0.6 and 1.9 kbar. A later, probably Carboniferous, stage of mineralization was associated with base-metal sulphide deposition and involved a low to moderate temperature (Th 70 to 240°C), low to moderate salinity (0 to 20 wt% NaCl eq.), H2O-salt fluid. The presence of both fluids at many of the deposits shows that the fractures hosting the deposits acted as long-term controls for fluid migration and the location of Caledonian metalliferous fluids as well as Carboniferous metalliferous fluids. Abstract Copyright (2005), Wiley Periodicals, Inc.
Sections:Economic minerals and ore deposits
Subsections:Metallic deposits: regional
Subjects:Base metals; Caledonian Orogeny; Carboniferous; Dalradian; Deposition; Fluid inclusions; Fractures; Inclusions; Metal ores; Metamorphism; Mineral deposits, genesis; Mineralization; Ordovician; Ore-forming fluids; Paleozoic; SEM data; Silurian; Sulfides; Temperature; Europe; Great Britain; Northern Ireland; Scotland; United Kingdom; Western Europe; Southwestern Scotland
Coordinates:N560000 N560000 W0050000 W0050000
Abstract Numbers:05M/360
Record ID:2005032907
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom
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