A chronology of foreland deformation; ultra-violet laser 40Ar/39Ar dating of syn/late-orogenic intrusions from the Variscides of Southwest Ireland

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doi: 10.1016/j.jsg.2005.02.003
Authors:Quinn, D.; Meere, P. A.; Wartho, J. A.
Author Affiliations:Primary:
National University of Ireland, Department of Geology, Cork, Ireland
Curtin University, Australia
Volume Title:Journal of Structural Geology
Source:Journal of Structural Geology, 27(8), p.1413-1425. Publisher: Elsevier, Oxford, International. ISSN: 0191-8141
Publication Date:2005
Note:In English. 38 refs.; illus., incl. 1 table, sketch map
Summary:The Upper Palaeozoic sedimentary rocks of the Munster and South Munster Basins, southern Ireland, lie within the Rhenohercynian Zone of the European Variscan orogeny. This foreland region accommodated shortening during the Asturian phase of Variscan deformation at the end of the Carboniferous by the development of kilometre-scale and lower order folding, high angle reverse faulting and regional fabric development. At the southwestern extremity of the belt lies the Black Ball/White Ball Heads area of the Beara Peninsula where high-level igneous intrusions locally exhibit a close relationship with both the ductile and late brittle phases of Variscan deformation. 40Ar/39Ar ultra-violet laser analysis of phlogopite crystals from these intrusions (principally trachytic dykes) has yielded ages that, when combined with structural field relationships, help to constrain the timing of Variscan deformation in southern Ireland. These ages include 314.44±1.00 Ma for a penetratively deformed lamprophric pipe on Black Ball Head, 301.98±1.47-298.08±0.61 Ma for dyke material associated with later stage brittle deformation and a date of 296.88±0.60 Ma for an undeformed post-orogenic dyke on White Ball Head. Abstract Copyright (2005) Elsevier, B.V.
Sections:Age determination; Mineral data; Petrology
Mineral Groups:Sheet silicates
Subjects:Absolute age; Ar/Ar; Dates; Deformation; Dikes; Intrusions; Lower Paleozoic; Mica group; Paleozoic; Permian; Phlogopite; Preferred orientation; Sheet silicates; Silicates; Structural analysis; Thermal history; Europe; Ireland; Variscides; Western Europe; Beara Peninsula; Munster Basin; Southwestern Ireland
Coordinates:N390000 N410000 E0590000 E0560000
Abstract Numbers:05M/3825
Record ID:2006027624
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands
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