Basin structure and Tertiary magmatism on Skye, NW Scotland

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doi: 10.1144/gsjgs.151.6.0931
Authors:Butler, R. W. H.; Hutton, D. H. W.
Author Affiliations:Primary:
University of Leeds, Department of Earth Sciences, Leeds, United Kingdom
Other:
University of Durham, United Kingdom
Volume Title:Journal of the Geological Society of London
Source:Journal of the Geological Society of London, Vol.151 (Part 6), p.931-944. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0016-7649
Publication Date:1994
Note:In English. 59 refs.; illus., incl. sects., geol. sketch maps
Summary:The emplacement of igneous bodies into upper crustal rocks of sedimentary basins is likely to be stongly influenced by the geometry of the pre-existing basin structures. Such controls have been investigated using examples from the Tertiary igneous complexes of Skye, part of the Sea of the Hebrides basin of NW Scotland. Mesozoic structures are traced near the igneous complexes using geological relationships preserved unconformably beneath the widespread basaltic lava fields. This unconformity represents a period of Cretaceous uplift and denudation of the basin and its flanks and seals stratigraphically the major basin faults, preserving field relationships that allow these faults to be traced in the country rocks to the intrusions. The major Camasunary fault is separated from the Raasay fault via a series of minor grabens, linked by a series of faults that transferred Mesozoic displacement between the principal fault strands. The major gabbroic centres do not appear to have been controlled by upper crustal structures, having been emplaced into the footwalls of major faults, but minor synmagmatic displacements on the basin faults may have generated dilatational sites facilitating emplacement. In contrast, the granitic melts have been emplaced as sheets and domed into the sediments and overlying lava pile, reactivating segments of the basin fault network. Doming occurred from an array of sills whose levels and transgressive forms are strongly related to inferred Mesozoic basin structures. The major fold structures of Tertiary age in S Skye are interpreted as accommodating granitic emplacement rather than crustal shortening. These interpretations are illustrated by field relationships mapped in the vicinity of the Coire Uaigneich granophyre. [R.A.H.]
Subjects:Basins; Cenozoic; Emplacement; Faults; Granites; Igneous rocks; Intrusions; Magmas; Plutonic rocks; Sedimentary basins; Tertiary; Europe; Great Britain; Hebrides; Highland region Scotland; Inner Hebrides; Inverness-shire Scotland; Isle of Skye; Scotland; United Kingdom; Western Europe; Igneous activity
Abstract Numbers:95M/2132
Record ID:1997005345
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
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