The structural setting and U-Pb geochronology of Knoydartian pegmatites in W Inverness-shire; evidence for Neoproterozoic tectonothermal events in the Moine of NW Scotland

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doi: 10.1144/gsjgs.155.4.0685
Authors:Rogers, G.; Hyslop, E. K.; Strachan, R. A.; Peterson, B. A.; Holdsworth, R. E.
Author Affiliations:Primary:
Scottish Universities Research and Reactor Centre, Isotope Geosciences Unit, Edinburgh, United Kingdom
British Geological Survey, United Kingdom
Oxford Brookes University, United Kingdom
University of Durham, United Kingdom
Volume Title:Journal of the Geological Society of London
Source:Journal of the Geological Society of London, Vol.155(Part 4), p.685-696. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0016-7649
Publication Date:1998
Note:In English. 78 refs.; illus., incl. 1 table, geol. sketch maps
Summary:U-Pb monazite data for the Ardnish and Sgurr Breac pegmatites in the SW Moine block give Knoydartian ages of 827 ± 2 and 784 ± 1 m.y., respectively. Structural and metamorphic studies on the pegmatites and the local Moine metasediments suggest that pegmatite generation was a result of localized high-T shearing and metamorphism in the pelitic horizons; the local garnet-grade metamorphism is interpreted as being contemporaneous with the shearing and pegmatite generation, and was thus Knoydartian in age. Chemical zoning profiles in garnets are consistent with their growth during prograde regional metamorphic increases in P and T. The ∼ 45 m.y. difference between the pegmatite ages is taken to imply that the Knoydartian tectonothermal event was diachronous. [R.A.H.]
Sections:Age determination
Subjects:Absolute age; Dates; Garnet group; Grade; Granites; Igneous rocks; Metamorphism; Moinian; Neoproterozoic; Nesosilicates; Orthosilicates; P-T conditions; Pegmatite; Plutonic rocks; Precambrian; Proterozoic; Regional metamorphism; Silicates; Tectonic elements; Tectonics; U/Pb; Upper Precambrian; Europe; Great Britain; Highland region Scotland; Inverness-shire Scotland; Moine thrust zone; Scotland; United Kingdom; Western Europe
Abstract Numbers:98M/3343
Record ID:1998042285
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
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