Late Variscan strike-slip tectonics between the Teplá-Barrandian and Moldanubian terranes (Czech Bohemian Massif): petrostructural evidence
- 1 September 1999
- journal article
- Published by Geological Society of London in Journal of the Geological Society
- Vol. 156 (5), 1003-1020
- https://doi.org/10.1144/gsjgs.156.5.1003
Abstract
In the Variscan Bohemian Massif (Czech Republic), no agreement has been reached on the nature of the relationship between the Teplá-Barrandian and the Moldanubian terranes. However, the Teplá-Barrandian is interpreted as a central segment separating the Moldanubian and Saxothuringian terranes and its position is therefore essential for any reconstruction of this part of the Variscan belt. Our petrological and structural study in the Domazlice-Klatovy region spans the boundary between the Teplá-Barrandian and Moldanubian terranes. There is no conformity of ductile structures in both domains near their interface and their P-T evolution is separate in time. The development of major structures and associated metamorphism in the southwestern part of the Barrandian was accompanied by syntectonic intrusions of granitoid and diorite bodies, dated at about 520 Ma. The Moldanubian migmatites are characterized by a LP-HT metamorphism that possibly took place at about 320 Ma. The metamorphic record of the Barrandian rocks shows no influence of the Moldanubian partial melting. The contacts are marked by semi-brittle to brittle structures: sinistral strike-slip faulting developed in the Central Bohemian Shear Zone, whereas the West Bohemian Shear Zone acted as a semi-brittle normal fault with a dextral component. Both shear zones may be nearly contemporaneous, accommodating a bulk N-S compression. The Central Bohemian Shear Zone was later reactivated in a dextral regime. Although timing is uncertain, the juxtaposition of both terranes took place probably in the waning stages of the Variscan orogeny, earlier than the late Stephanian. We argue that the late-orogenic (semi)brittle strike-slip tectonics modified considerably the face of the Bohemian Massif and the geodynamic models of the Bohemian Massif have to be reviewed with reference to this essential point.Keywords
This publication has 47 references indexed in Scilit:
- Metapegmatites in the western Bohemian massif: ages of crystallisation and metamorphic overprint, as constrained by U–Pb zircon, monazite, garnet, columbite and Rb–Sr muscovite dataInternational Journal of Earth Sciences, 1998
- Variscan vs Cadomian tectonothermal activity in northwestern sectors of the Teplá-Barrandian zone, Czech Republic: constraints from 40 Ar/ 39 Ar agesInternational Journal of Earth Sciences, 1998
- Late Cadomian crustal tilting and Cambrian transtension in the Teplá–Barrandian unit (Bohemian Massif, Central European Variscides)International Journal of Earth Sciences, 1997
- Crustal evolution of the KTB drill site: From oldest relics to the Late Hercynian granitesJournal of Geophysical Research, 1997
- Strain and strain rate in a synkinematic trondhjemitic dike: evidence for melt-induced strain softening during shearing (Bohemian Massif, Czech Republic)Journal of Structural Geology, 1997
- Accretionary history and crustal evolution of the Variscan belt in Western EuropeTectonophysics, 1991
- Structural model for the Saxothuringian-Moldanubian suture in the Variscan basement of the Oberpfalz (Northeastern Bavaria, F.R.G.) interpreted from geophysical dataTectonophysics, 1989
- The development of the Central European continental crust since the Early Archaean based on conventional and ion-microprobe dating of up to 3.84 b.y. old detrital zirconsTectonophysics, 1989
- Inversion tectonics along the Western margin of the Bohemian MassifTectonophysics, 1987
- The Variscan Belt in Central Europe: Main structures, geodynamic implications, open questionsTectonophysics, 1984