The Rhenohercynian passive margin of SW England : development, inversion and extensional reactivation
Shail, Robin K.; Leveridge, Brian E.. 2009 The Rhenohercynian passive margin of SW England : development, inversion and extensional reactivation. Comptes Rendus Geoscience, 341 (2-3). 140-155. 10.1016/j.crte.2008.11.002Before downloading, please read NORA policies.
The SW England Rhenohercynian passive margin initiated with rift-related non-marine sedimentation and bimodal magmatism (Late Lockhovian). Continued lithospheric extension resulted in the exhumation of mantle peridotites and limited seafloor spreading (Emsian-Eifelian). Variscan convergence commenced during the Late Eifelian and was coeval with rifting further north. Collision was marked by the Early Carboniferous emergence of deep marine sedimentary/volcanic rocks from the distal continental margin, oceanic lithosphere, pre-rift basement and upper plate gneisses (correlated with the Mid-German Crystalline High of the Saxothuringian Zone). Progressive inversion of the passive margin was strongly influenced by rift basin geometry. Convergence ceased in the Late Carboniferous and was replaced by an extensional regime that reactivated basin controlling/thrust faults and reorientated earlier fabrics (Start-Perranporth Zone). The resultant exhumation of the lower plate was accompanied by emplacement of the Early Permian SW England granites and was contemporaneous with upper plate sedimentary basin formation above the reactivated Rhenohercynian suture. The Rhenohercynian passive margin probably developed in a marginal basin north of the Rheic Ocean or, possibly, a successor basin following its closure. The Lizard ophiolite is unlikely to represent Rheic Ocean floor or associated forearc (SSZ) crust. The Rheic and Rhenohercynian sutures may be coincident or the Rheic suture may be located further south in the Léon Domain.
|Programmes:||BGS Programmes 2009 > Geology and Landscape England|
|Additional Keywords:||Passive margins, Southwest England, Variscan|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||08 May 2009 12:52|
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