Number of the records: 1
Deciphering the Variscan tectonothermal overprint and deformation partitioning in the Cadomian basement of the Teplá-Barrandian unit, Bohemian Massif
- 1.
SYSNO ASEP 0381768 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Deciphering the Variscan tectonothermal overprint and deformation partitioning in the Cadomian basement of the Teplá-Barrandian unit, Bohemian Massif Author(s) Hajná, J. (CZ)
Žák, J. (CZ)
Kachlík, V. (CZ)
Chadima, Martin (GLU-S) RID, SAISource Title International Journal of Earth Sciences. - : Springer - ISSN 1437-3254
Roč. 101, č. 7 (2012), s. 1855-1873Number of pages 19 s. Publication form WWW - WWW Language eng - English Country DE - Germany Keywords Avalonian-Cadomian belt ; Bohemian Massif ; Shear zone ; Teplá-Barrandian unit ; transpression ; Variscan orogeny Subject RIV DB - Geology ; Mineralogy Institutional support GLU-S - RVO:67985831 UT WOS 000308818500010 EID SCOPUS 84866469090 DOI 10.1007/s00531-012-0753-8 Annotation The Teplá–Barrandian unit (TBU) has long been considered as a simply bivergent supracrustal ‘median massif’ above the Saxothuringian subduction zone in the Variscan orogenic belt. This contribution reveals a much more complex style of the Variscan tectonometamorphic overprint and resulting architecture of the Neoproterozoic basement of the TBU. For the first time, we describe the crustal-scale NE–SW-trending dextral transpressional Krakovec shear zone (KSZ) that intersects the TBU and thrusts its higher grade northwestern portion severely reworked by Variscan deformation over a southeastern very low grade portion with well-preserved Cadomian structures and only brittle Variscan deformation. The age of movements along the KSZ is inferred as Late Devonian (~380–370 Ma). On the basis of structural, microstructural, and anisotropy of magnetic susceptibility data from the KSZ, we propose a new synthetic model for the deformation partitioning in the Teplá–Barrandian upper crust in response to the Late Devonian to early Carboniferous subduction and underthrusting of the Saxothuringan lithosphere. We conclude that the Saxothuringian/Teplá–Barrandian convergence was nearly frontal during ~380–346 Ma and was partitioned into pure shear dominated domains that accommodated orogen-perpendicular shortening alternating with orogen-parallel high-strain domains that accommodated dextral transpression or bilateral extrusion. The synconvergent shortening of the TBU was terminated by a rapid gravity-driven collapse of the thickened lithosphere at ~346–337 Ma followed by, or partly simultaneous with, dextral strike-slip along the Baltica margin-parallel zones, driven by the westward movement of Gondwana from approximately 345 Ma onwards. Workplace Institute of Geology Contact Jana Popelková, popelkova@gli.cas.cz, Sabina Janíčková, Tel.: 233 087 272 Year of Publishing 2013
Number of the records: 1