Fold-thrust-belt geometry and detailed structural evolution of the Silesian nappe – eastern part of the Polish Outer Carpathians (Bieszczady Mts.)

Authors

  • Jacek Rubinkiewicz Institute of Geology, University of Warsaw, Żwirki i Wigury Str., 93 PL-02-089 Warszawa

Keywords:

Fold-thrust belt, Imbricate slices, Mesoscopic structures, Structural analysis, Outer Carpathians, Silesian nappe, Central Carpathian Depression, Fore-Dukla thrust sheet

Abstract

On the basis of field studies of mesoscopic structures, and analysis of radar and aerial photos together with seismic data, the structure and structural evolution of a part of the Silesian nappe was established. In the study area the Silesian nappe comprises two tectonic units: the Central Carpathian Depression and the Fore-Dukla thrust sheet, separated by a fault. The Central Carpathian Depression is built of several mapscale slices. The slices comprise map-scale NE-verging anticlines, with additional synclines to the south-east. The slices are separated by steeply dipping forelimb-thrusts, which connect together at a depth of ca. 6-7 km into a single sole thrust and form a leading imbricate fan. To the west of the Rabe-Baligród fault zone the fault between the Central Carpathian Depression and the Fore-Dukla thrust sheet is a typical thrust. Eastwards from this fault zone it becomes a steeply NE-dipping normal fault. The Silesian nappe is cut by map-scale oblique and transverse, mainly strike-slip faults – some of them are tear faults. Longitudinal strike-slip faults indicate dextral movement along the pre-existing thrusts. The structural evolution of the Silesian nappe comprises here eight pre-, syn- and post-orogenic stages beginning with the formation of clastic veins, followed by folding, thrusting, strike-slip faulting and terminating with normal faulting.

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Published

2007-12-10

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Section

Articles