The South Barra shear zone: a composite Inverian–Laxfordian shear zone and possible Terrane boundary in the Lewisian gneiss complex of the Isle of Barra, NW Scotland

MacDonald, J. M. and Goodenough, K. M. (2013) The South Barra shear zone: a composite Inverian–Laxfordian shear zone and possible Terrane boundary in the Lewisian gneiss complex of the Isle of Barra, NW Scotland. Scottish Journal of Geology, 49(2), pp. 93-103. (doi:10.1144/sjg2011-463)

[img]
Preview
Text
103600.pdf - Accepted Version

991kB

Abstract

The Lewisian Gneiss Complex (LGC) of NW Scotland largely comprises Archaean tonalite–trondhjemite–granodiorite (TTG) gneisses variably reworked in the Palaeoproterozoic. One form of this heterogeneous reworking is the formation of major shear zones in the earliest Palaeoproterozoic which are then reactivated in the late Palaeoproterozoic. Recent remapping of the LGC of SE Barra, in the southern Outer Hebrides, has led to the interpretation of such a composite shear zone, the Southeast Barra Shear Zone (SBSZ). The SBSZ separates a block of heterogeneously overprinted pyroxene-bearing TTG gneisses from a dioritic meta-igneous complex to the west. Despite a lack of geochronological data, the juxtaposition of different protolith rocks along the SBSZ raises the possibility it may be a previously unrecognized terrane boundary.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:MacDonald, Dr John
Authors: MacDonald, J. M., and Goodenough, K. M.
Subjects:Q Science > QE Geology
College/School:College of Science and Engineering > School of Geographical and Earth Sciences > Earth Sciences
Journal Name:Scottish Journal of Geology
Publisher:Geological Society Publishing House
ISSN:0036-9276
ISSN (Online):2041-4951
Copyright Holders:Copyright © 2013 Scottish Journal of Geology
First Published:First published in Scottish Journal of Geology 49(2):93-103
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

University Staff: Request a correction | Enlighten Editors: Update this record