Partial melting of the Appin Quartzite driven by fracture-controlled H2O infiltration in the aureole of the Ballachulish igneous complex, Scottish Highlands

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doi: 10.1007/s004100050529
Authors:Holness, M. B.; Clemens, J. D.
Author Affiliations:Primary:
University of Cambridge, Department of Earth Sciences, Cambridge, United Kingdom
Kingston University, United Kingdom
Volume Title:Contributions to Mineralogy and Petrology
Source:Contributions to Mineralogy and Petrology, 136(1-2), p.154-168. Publisher: Springer International, Heidelberg-New York, International. ISSN: 0010-7999
Publication Date:1999
Note:In English. 44 refs.; illus., incl. sect., 2 tables, geol. sketch map
Summary:The Ballachulish igneous complex consists of an outer quartz diorite and an inner granite, emplaced at ∼ 300 MPa, initially at 1000-1050°C. In the contact aureole (0.5-2 km wide) the arkosic-Appin quartzite is seen to have undergone partial melting up to 500 m from the W vertical contact. Although perhaps not the only possible source of fluid, simple models show that H2O evolved from the pluton would have been volumetrically sufficient and persistent enough to account for the observed partial melting. A time-integrated fluid flux of 7000 kg/m2 from the pluton would have been necessary to account for the observed amounts of partial melt in the quartzite. The infiltration was controlled by hydraulic fracturing, with fracture density determining melting efficiency. Bulk-rock permeability is calculated to be 10-20 m2, an order of magnitude lower than that necessary to permit pervasive flow of all the fluid exsolving from the pluton. [R.A.H.]
Subsections:Metamorphism: thermal, metasomatic
Subjects:Aureoles; Fractures; Granitic composition; Igneous rocks; Infiltration; Metamorphic rocks; Partial melting; Quartzites; Water; Ballachulish Complex; Europe; Great Britain; Scotland; Scottish Highlands; United Kingdom; Western Europe; Appin Quartzite
Abstract Numbers:01M/995
Record ID:2000016124
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
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