Original paper

Syn-collisional extension in the West/East Sudetes boundary zone (NE Bohemian Massif): structural and metamorphic record in the Jełgowa Beds from the Strzelin Massif (East Fore-Sudetic Block)

Szczepański, Jacek; Mazur, Stanislaw

Abstract

In the Jegłowa Beds three deformation events D1 - D3 of regional extent were recorded. The poorly documented D1 event is correlated with E- to NE-ward nappe thrusting accompanied by prograde metamorphism under greenschist-facies conditions. D2 corresponds to coaxial shortening due to E-W compression. The D3 event includes bivergent dip-slip normal shearing induced by NNE-SSW extension resulting from extensional collapse of the overthickened crust. This deformation event was responsible for the present-day domal structure of the Strzelin Massif with higher-grade rocks in its core and lower-grade rocks on the limbs. LP/MT to HT metamorphism ranging up to amphibolite facies conditions accompanied the extension.

Keywords

Bohemian MassifMoravo-Silesian ZoneEast SudetesFore-Sudetic Blockcollisionextensiondeformationmetamorphism.