The age of the Mesoproterozoic Stoer Group sedimentary and impact deposits, NW Scotland

Parnell, J., Mark, D. , Fallick, A., Boyce, A. and Thackrey, S. (2011) The age of the Mesoproterozoic Stoer Group sedimentary and impact deposits, NW Scotland. Journal of the Geological Society, 168, pp. 349-358. (doi: 10.1144/0016-76492010-099)

Full text not currently available from Enlighten.


The Mesoproterozoic Stoer Group of the ‘Torridonian' has been dated at 1177 ± 5 Ma (2σ), based on <sup>40</sup>Ar/<sup>39</sup>Ar dating of authigenic K-feldspars precipitated in degassing structures within the Stac Fada Member, interpreted previously as an impact ejecta deposit. Fluid inclusion analysis of the K-feldspar shows that it precipitated from hot fluids, and so must immediately post-date emplacement of the ejecta blanket. The oxygen isotopic composition of K-feldspar is remarkably constant at 9.7 ± 0.2‰ (V-SMOW) and is consistent with derivation from evaporated lake water. The new age supports previous determinations of 1199 ± 70 Ma from Pb–Pb dating of limestone and 1180 Ma from palaeomagnetic data, but provides much higher precision.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Mark, Professor Darren and Boyce, Professor Adrian and Fallick, Professor Anthony
Authors: Parnell, J., Mark, D., Fallick, A., Boyce, A., and Thackrey, S.
Subjects:G Geography. Anthropology. Recreation > GE Environmental Sciences
College/School:College of Science and Engineering > Scottish Universities Environmental Research Centre
Journal Name:Journal of the Geological Society
Publisher:Geological Society of London
ISSN (Online):2041-479X
Published Online:01 January 2010

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