Petrogenesis of Lewisian amphibolite dykes from Clashnessie Bay, near Stoer, Sutherland

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doi: 10.1144/sjg18020167
Authors:Sills, J. D.; Windley, B. F.
Author Affiliations:Primary:
Univ. Leicester, Dep. Geol., Leicester LE1 7RH, United Kingdom
Volume Title:Scottish Journal of Geology
Source:Scottish Journal of Geology, 18(2-3), p.167-176. Publisher: Scottish Academic Press, Edinburgh, United Kingdom. ISSN: 0036-9276
Publication Date:1982
Note:In English. 1 p. refs.; illus. incl. 8 anal., 1 table, sketch map, geol. sketch map
Summary:Six thin amphibolite dykes which cut the NW Scottish Scourian gneisses (approx 2700 m.y. old) in Clashnessie Bay have a different orientation to the Scourie dykes (a prominent approx 2400 m.y.-old tholeiitic dyke swarm). The amphibolite dykes were intruded, metamorphosed, and folded some time between the end of the Scourian granulite-facies metamorphism and the intrusion of the Scourie dykes, and were possibly associated with the Inverian period of folding and retrogression. Major- and trace-element analyses (XRF) of eight samples show that they have a very uniform composition but are chemically distinct from Scourie dykes and are low-K tholeiitic andesites with SiO2 54-57%. They could have formed from a tholeiitic magma by hornblende fractionation. [R.A.H.]
Subjects:Amphibolites; Dikes; Fractional crystallization; Genesis; Intrusions; Magmas; Major elements; Metamorphic rocks; Petrology; Precambrian; Tholeiitic composition; Europe; Great Britain; Highland region Scotland; Northern Highlands; Scotland; Sutherland Scotland; United Kingdom; Western Europe; Clashnessie Bay; Point of Stoer
Coordinates:N581300 N581300 W0052000 W0052000
Abstract Numbers:82M/5032
Record ID:1983020849
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom, Reference includes data from PASCAL, Institute de l'Information Scientifique et Technique
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