Testing for the presence of a terrane boundary within Neoproterozoic (Dalradian) to Cambrian siliceous turbidites at Callander, Perthshire, Scotland

Tanner, P.W.G. and Pringle, M.S. (1999) Testing for the presence of a terrane boundary within Neoproterozoic (Dalradian) to Cambrian siliceous turbidites at Callander, Perthshire, Scotland. Journal of the Geological Society, 156(6), pp. 1205-1216.

Abstract

The Southern Highland Group (Dalradian) and Keltie Water Grit Formation, which includes the Lower Cambrian Leny Limestone, form an inverted, 1.4 km thick, largely arenaceous, sequence at Callander. The grits have the same detrital mineralogy throughout, mainly quartz, plagioclase (An(1-3)), muscovite, and biotite. Chlorite formed from detrital biotite during low-grade regional metamorphism (T less than 270 °C). There are some vertical changes in major element (but not trace element) chemistry of the grits, and detrital muscovites have a wide, but comparable, range in composition throughout, apart from an influx of Na-rich micas in the Keltie Water Grits. 40Ar/39Ar laser fusion dating of detrital muscovites yields an age spectrum with a peak at 1600-1800 Ma in the Dalradian rocks; similar old ages occur in the Keltie Water Grits but are diluted by ages of 507 - 886 Ma. We interpret these new data as showing that the rocks were most likely deposited as a single sequence, possibly with a disconformity, in Neoproterozoic to Early Cambrian times, before the onset of Grampian orogenesis in the Early Palaeozoic. No major structural or straitigraphical breaks have been identified and there is no direct evidence for the presence of two separate terranes.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: UNSPECIFIED
• Authors: Tanner, P.W.G., and Pringle, M.S.
• Subjects: Q Science > QE Geology
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Journal of the Geological Society
• Publisher: Geological Society of London
• ISSN: 0016-7649
• Copyright Holders: Copyright © 1999 The Geological Society of London
• First Published: First published in Journal of the Geological Society 156 (6)1205 - 1216
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher.

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
19054	1	PROVENENACE OF ROCKS AT THE HIGHLAND BORDER IN SCOTLAND BY 40Ar/39Ar DATING OF DETRITAL WHITE MICAS	P Tanner	Natural Environment Research Council (NERC)	IP/442/0395	SCHOOL OF GEOGRAPHICAL & EARTH SCIENCES