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Grahame J. H. Oliver, Simon A. Wilde, and Wan Yusheng
Geochronology and geodynamics of Scottish granitoids from the late Neoproterozoic break-up of Rodinia to Palaeozoic collision
Journal of the Geological Society of London (May 2008), 165(3):661-674

Abstract:
Thirty-seven granitoids from Scotland have been dated using the sensitive high-resolution ion microprobe zircon method. Granitoids were intruded during: (1) crustal stretching at c. 600 Ma after Rodinia broke up (A-types); (2) the Grampian event of crustal thickening when the Midland Valley Arc terrane collided with Laurentia at c. 470 Ma (S-types); (3) erosion and decompression of the over-thickened Laurentian margin at c. 455 Ma (S-types); (4) subduction of Iapetus Ocean lithosphere under Laurentia starting at 430 Ma (I-types); (5) roll-back beginning at 420 Ma (I-types); (6) bilateral slab break-off and lithospheric delamination at 410 Ma (I- and S-type granites) when Baltica hard-docked against the Northern Highland terrane and Avalonia soft-docked against the Grampian Highland terrane. Far-field Acadian events at 390 Ma were recorded by I-type granites intruded along active sinistrally transpressive faults. I-types formed in lower crustal hot zones above subduction zones, whereas S-types formed in lower crustal hot zones above lithospheric windows through which hot asthenosphere had risen.

Index Terms/Descriptors:
absolute age; asthenosphere; Avalonia; Baltica; Caledonian Orogeny; crustal thickening; dates; delamination; Europe; geodynamics; Grampian Highlands; Grampian Orogeny; granites; Great Britain; I-type granites; Iapetus; igneous rocks; ion probe data; Laurentia; lithosphere; lower Paleozoic; mass spectra; Midland Valley; Neoproterozoic; nesosilicates; oceanic lithosphere; Ordovician; orthosilicates; Paleozoic; plate tectonics; plutonic rocks; Precambrian; Proterozoic; rifting; Rodinia; S-type granites; Scotland; Scottish Highlands; SHRIMP data; silicates; spectra; subduction; U/Pb; United Kingdom; upper Precambrian; Western Europe; zircon; zircon group

Latitude & Longitude:
N55°15'00" - N57°45'00" and W5°50'00" - W1°45'00" (Search for maps and images at Alexandria Digital Library)

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