Uplift patterns and orogenic evolution in the Scottish Dalradian

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doi: 10.1144/gsjgs.142.1.0111
Authors:Dempster, T. J.
Author Affiliations:Primary:
University of Edinburgh, Grant Institute of Geology, Edinburgh, United Kingdom
Other:
Leeds University, United Kingdom
Volume Title:Conditions of Dalradian metamorphism
Volume Authors:Graham, Colin M., convener; Harte, Ben
Source:Journal of the Geological Society of London, Vol.142(Part 1), p.111-128; Conditions of Dalradian metamorphism, Edinburgh, United Kingdom, Sept. 20-21, 1983, convened by Colin M. Graham and Ben Harte. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0016-7649
Publication Date:1985
Note:In English. Includes appendices. 44 refs.; illus., incl. 3 tables, geol. sketch maps
Summary:Numerous Rb/Sr and K/Ar mineral ages from the Dalradian rocks of Angus and Perthshire indicate considerable diachronism of cooling, following the Caledonian regional metamorphism. The oldest mineral ages (approx 515 m.y.) are similar to the independent estimates of peak metamorphic age, and hence indicate very rapid cooling; they occur in the highest grade samples of the Angus region and are associated with localized uplift. Regional rapid uplift events at 460-440 and 410-390 m.y. may also be recognized and correlated with structural and igneous activity and metamorphic dates within the Scottish Highlands. Thermal models show the importance of localized and discontinuous uplift in determining both the timing of metamorphism and the shape of the P-T paths; the major diachroneity of metamorphism (and granite production) in the Scottish Highlands is probably depth controlled rather than representing major lateral diachroneity of thickening or heat sources. Localized uplift may exercise considerable control on mineral facies variation within orogenic belts. The uniform block uplift models frequently used in the interpretation of metamorphic and structural phenomena in orogenic belts are an oversimplification of the real events. [R.A.H.]
Subjects:Absolute age; Amphibole group; Caledonian Orogeny; Chain silicates; Cooling; Dalradian; Dates; Deformation; Erosion; Geotraverses; Granites; Igneous rocks; Intrusions; Isograds; Isotope ratios; Isotopes; K/Ar; Lower Paleozoic; Magmatism; Metamorphism; Mica group; Mineral composition; Models; Orogenic belts; Orogeny; P-T conditions; P-T-t paths; Paleozoic; Plutonic rocks; Rb/Sr; Regional metamorphism; Sheet silicates; Silicates; Stratigraphic units; Tectonics; Uplifts; Zoning; Europe; Great Britain; Scotland; United Kingdom; Western Europe
Coordinates:N561500 N570000 W0023000 W0034500
Abstract Numbers:85M/1079
Record ID:2003045109
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
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