Recent Tectonic Movements in the NE Part of the Bohemian Massif, Czech Republic, Indicated by the Brittle Tectonic Approach.
Abstract
The paper deals with tectonic movements on reactivated Variscian fault planes in the most interesting area of the NE part of the Bohemian Massif close to an important local fault structure - the Sudetic Marginal Fault (SMF). The importance of the area has been documented by number of papers and works in last few decades but even now the situation is not clear enough.
The authors has studied tectonic movement along the SMF using standard geological methods and GPS long term monitoring as well. The geological part of research has been started in the vicinity of the Vápenná village in the Rychlebské Mountains where Devonian crystalline limestones of the Branná group and Paleozoic granites of the Žulová granite pluton are separated by the Sudetic Marginal Fault.
Hundreds of measurements of joints and small-scale faults have been realized in three limestone quarries on the west side of the fault and several small granite quarries on the east side. Kinematic indicators were observed as well.
Long term GPS monitoring has been performed by the Department of geodynamics of IRSM AS CR, v.v.i. since 1997 in the Rychlebské Mountains and the Jeseníky Mountains. Results of both methods were compared and discussed.
Observed presence of kinematic indicators points to reactivation of fault of E-W (limestone) and NE-SW (granites) direction. General situation of recent tectonic movements in the NE part of the Bohemian Massif has been determined.
Directions and speed of the movements were measured and displayed.