The Caledonian strike-swing and associated lineaments in NW Ireland and adjacent areas; sedimentation, deformation and igneous intrusion patterns

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doi: 10.1144/gsjgs.153.3.0345
Authors:Hutton, D. H. W.; Alsop, G. I.
Author Affiliations:Primary:
University of Durham, Department of Geological Sciences, Durham, United Kingdom
Other:
University of London, United Kingdom
Volume Title:Journal of the Geological Society of London
Source:Journal of the Geological Society of London, Vol.153(Part 3), p.345-360. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0016-7649
Publication Date:1996
Note:In English. 76 refs.; illus., incl. 1 table, geol. sketch maps
Summary:Part of the major swing in strike associated with the Greenland-Labrador promontory of the North Atlantic Caledonides is well exposed in the metasedimentary and meta-igneous rocks of the Neo-Proterozoic Dalradian supergroup in NW Ireland. The strike swing is shown to have controlled Dalradian stratigraphy and sedimentation patterns and is therefore ≥ ∼ 600 m.y. in age. Accurate restoration of the sinistral displacement on a late Calledonian fault system shows that the apices of the strike swing at different stratigraphic levels define a line trending ∼ N12°E, coincident with six out of eight Devonian Donegal granites, the vast majority of the mantle-related ultrabasic 'appinite' suite, and the highest density of the Neo-Proterozoic basic tholeiite suite. These and other data suggest that the Donegal lineament is the expression of a major steeply inclined fault in the basement beneath the Dalradian; this fault, which might be as old as 1800 m.y., probably reached down into the lithospheric mantle, controlling igneous activity, including the ascent, emplacement site and perhaps sources of the magmas. [R.A.H.]
Subjects:Caledonian Orogeny; Deformation; Faults; Granites; Igneous rocks; Lineaments; Paleozoic; Plutonic rocks; Sedimentation; Tectonics; Europe; Ireland; Western Europe; Northwestern Ireland
Abstract Numbers:96M/4613
Record ID:1996049277
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
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