Geodynamic model for the Palaeozoic crustal consolidation of Western and Central Europe
1986; Elsevier BV; Volume: 126; Issue: 2-4 Linguagem: Inglês
10.1016/0040-1951(86)90236-2
ISSN1879-3266
Autores Tópico(s)Geological Formations and Processes Exploration
ResumoThe crystalline basement of Western and Central Europe consists of a mosaic of crustal elements which were consolidated during pre-Grenvillian, the Grenvillian-Dalslandian, Morarian, Cadomian, Caledonian and Hercynian orogenic cycles. Contemporaneous with the Caledonian suturing of the Precambrian Laurentia-Greenland and Fennosarmatian shields a number of Gondwana-derived Cadomian micro-cratons were accreted to the southern margin of Laurasia. Following the Late Caledonian paroxysm, the Devonian and Early Carboniferous evolution of Europe was dominated by continued northward subduction of the Proto Tethys plate at an arc-trench system parallelling the southern margin of Laurasia, the accretion of additional Gondwana-derived continental fragments, back-arc rifting and a sinistral translation of major proportions between the Laurentia-Greenland and the Fennosarmatian sub-plates. The Acadian and Bretonian orogenies were of the Pacific type. The Visean collision of Gondwana with Laurasia marked the onset of the Himalayan-type Variscan orogeny, during which collision-related compressive stresses overpowered the Devonian-Early Carboniferous back-arc rift systems and caused the development/reactivation of A-subduction zones. The Central Armorican and Saxothuringian successor basins became folded and destroyed during the latest Visean, whilst the Variscan foredeep became scooped out, in part by nappes involving the basement, during the Late Westphalian. Major crustal shortening during the Variscan diastrophism was accompanied by the anatectic remobilisation of subducted crustal and upper mantle material and a widespread syn- and late-orogenic magmatism. The latest Carboniferous-Early Permian reorientation of the convergence direction between Gondwana and Laurasia induced the development of a complex wrench-fault system transecting the Variscan fold belt and an extensive post-orogenic volcanism. The hypotheses summarised here require confirmation by further palaeomagnetic and radiometric data and faunal analyses.
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