The area occupied by the Variscan belt of central Europe forms part of Gondwana-derived microplates (essentially Avalonia and Armorica) that, according to paleomagnetic data, juxtaposed Baltica and Laurentia from the Upper Ordovician to the Lower Devonian. The actual structure of this area is a puzzle of rather small fault-bounded crustal blocks, different in P-T-t-histories, which was created by later tectonic processes, at around 360 to 320 Ma. According to a common view and by contrast to paleomagnetic data, the structural record of fault-bounded blocks is interpreted in terms of Mid-Devonian to Lower Carboniferous amalgamation of narrow continental plates represented by the fault-bounded blocks themselves. However, this is not supported in this article. Instead, it will be shown that fault-systems and fault-bounded blocks were created by intraplate deformation of a weak domain of Gondwana-derived continental lithosphere, significantly after its accretion. Deformation was partitioned into newly formed deep-seated strike-slip and (kinematically connected) reverse or normal detachment systems. Large translation magnitudes caused juxtaposition of crustal areas of variable thickness. Until they were emplaced along the fault systems, the various categories of fault-bounded complexes record different tectonic events. Category 1 metamorphic complexes represent deep-seated parts of thickened crust, some time before unroofing on the detachment systems between about 340 (360) and 320 Ma. However, the record of subduction and extreme crustal thickening during earlier stages of the collision history was erased to a high degree and is only preserved by mineral and structural relics. Strike-slip and detachment systems propagated across and dismembered tectonic boundaries, formed during these early events Category 2 metamorphic complexes and the Barrandian Basin recording predominant pre-Late Devonian metamorphic or stratigraphic events represent the brittle upper crustal parts during continuing metamorphism in the category 1 complexes. Weakly or unmetamorphosed lower Paleozoic category 3 basins represent areas of thinned continental crust and record subsidence before, and to some degree, during activity of detachment systems. The complex overall kinematic pattern of block-bounding strike-slip and detachment systems indicates compression and extension acting simultaneously. This probably reflects the effects of continuing oblique plate convergence, rotation, and WSW-extrusion of fault bounded blocks, in addition to heating, and extensional flow of previously thickened crustal areas. ¿ American Geophysical Union 1996 |