Ordovician limestone clasts in the Lower Old Red Sandstone, Pentland Hills, southern Midland Valley Terrane

Armstrong, H.A., Owen, A.W. and Clarkson, E.N.K. (2000) Ordovician limestone clasts in the Lower Old Red Sandstone, Pentland Hills, southern Midland Valley Terrane. Scottish Journal of Geology, 36, pp. 33-37. (doi: 10.1144/sjg36010033)




In the southern part of the Scottish Midland Valley Lower Old Red Sandstone sedimentary and volcanic strata of the Lanark Group unconformably overlie inliers of largely marine Silurian rocks. The oldest of the four formations of the Lanark Group is the Greywacke Conglomerate Formation which contains clasts predominantly of greywacke, with subordinate volcanic rocks, cherts and limestones. The greywackes are known to have been derived from a cryptic source which lay to the south and east of the Midland Valley. Contrary to earlier, Silurian, age assessments of limestone clasts from the Greywacke Conglomerate Formation of the Pentland Hills, a conodont faunule described herein belongs in the uppermost Llanvirn to lower Caradoc P. anserinus Biozone. There are no Ordovician rocks exposed within the Pentland Hills inlier, and thus our new age data suggest that along with the other clasts, the limestones in the Greywacke Conglomerate are exotic to the Pentlands Sub-basin. The source area had a cover succession that included mid-Ordovician shallow marine carbonate and flysch.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Owen, Dr Alan
Authors: Armstrong, H.A., Owen, A.W., and Clarkson, E.N.K.
Subjects:Q Science > QE Geology
College/School:College of Science and Engineering > School of Geographical and Earth Sciences
Journal Name:Scottish Journal of Geology
Publisher:Geological Society of London
Copyright Holders:Copyright © 2000 The Geological Society of London
First Published:First published in Scottish Journal of Geology 36(1) 33-38
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher.

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