Paleozoic evolution of continental crust in the Beaujolais-Lyonnais area, northeastern part of the Massif Central, France

摘要: In the Beaujolais-Lyonnais area of northeastern Massif Central accretion continental and possibly oceanic crustal fragments occurred between Cambrian (?) early Carboniferous time. Three distinct lithotectonic units (terranes?) have been recognized. The southern (Lyonnais-) Unit consists medium- to high-grade metamorphics includes eclogites; it formed in Paleozoic. Brevenne-Unit north contains low- medium-grade metamorphic mafic felsic volcanics subordinate sedimentary rocks which originated during Paleozoic until Devonian time, a sialic back-arc environment or along an active margin. Beaujolais-Unit is represented by on south predominantly shallow marine clastics carbonates north. It developed late ensialic marginal basin. peak metamorphism Lyonnais-unit (HP/HT) was reached Silurian Subsequent NW-SE E-W oriented convergence produced mylonitic foliation, structural imbrication Lyonnais basement with SE-vergent folds accompanied metamorphism. Late Visean Namurian N-S directed N-vergent thrusting tectonic northern nonmetamorphic Beaujolais-Unit. Lyonnais-Unit updoming right-lateral high-angle normal faults followed emplacement voluminous granitic plutons origin. Permian thinning associated trending left-lateral strike-slip NE-SW faults. Basins that these contain red beds.