Laurentian origin of the Ordovician Grangegeeth volcanic arc terrane, Ireland
McConnell, Brian; Crowley, Quentin G.; Riggs, Nancy. 2010 Laurentian origin of the Ordovician Grangegeeth volcanic arc terrane, Ireland. Journal of the Geological Society, 167 (3). 469-474. 10.1144/0016-76492009-139Full text not available from this repository. (Request a copy)
U–Pb ages determined by laser-ablation multi-collector inductively coupled plasma mass spectrometry on 199 zircons from a lithic pumice tuff are the first isotopic ages from the Grangegeeth volcanic terrane of Ireland. The youngest zircon population (n = 24) yields an age of 465.4 +2.4/–3.1 Ma. Inherited zircons yield ages of c. 1120–1520, c. 1650–1914 and c. 2540–2890 Ma. The absence of zircons between c. 550 and 700 Ma argues against involvement of Avalonia as a source of inherited crystals. Overall, the inherited age spectra are characteristic of Laurentian crust or metasedimentary successions of peri-Laurentian provenance. These findings suggest that the Grangegeeth volcanic terrane does not represent a continuation of the intra-Iapetus Exploits arc of Newfoundland.
|Programmes:||BGS Programmes 2010 > NERC Isotope Geoscience Laboratory|
|Additional Information:||Supplementary material: Full analytical protocols, applied data corrections, processing and plotting rationales and data table for zircon LA-MC-ICP-MS analysis are available at http://www.geolsoc.org.uk/SUP18399.|
|Date made live:||30 Apr 2010 12:40|
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