The Carpathian Orava Basin is a tectonic structure filled with Neogene and Quaternary
deposits superimposed on the collision zone between the ALCAPA and European plates.
Tectonic features of the south-eastern margin of the Orava Basin and the adjoining
part of the fore-arc Central Carpathian Palaeogene Basin were studied. Field observations
of mesoscopic structures, analyses of digital elevation models and geological maps,
supplemented with electrical resistivity tomography surveys were performed. Particular
attention was paid to joint network analysis. The NE-SW-trending Krowiarki and HruStinka-Biela
Orava sinistral fault zones were recognized as key tectonic features that influenced
the Orava Basin development. They constitute the north-eastern part of a larger Mur-Murz-Zilina
fault system that separates the Western Carpathians from the Eastern Alps. The interaction
of these sinistral fault zones with the older tectonic structures of the collision
zone caused the initiation and further development of the Orava Basin as a strike-slip-related
basin. The Krowiarki Fault Zone subdivides areas with a different deformation pattern
within the sediments of the Central Carpathian Palaeogene Basin and was active at
least from the time of cessation of its sedimentation in the early Miocene. Comparison
of structural data with the recent tectonic stress field, earthquake focal mechanisms
and GPS measurements allows us to conclude that the Krowiarki Fault Zone shows a stable
general pattern of tectonic activity for more than the last 20 myr and is presently
still active.
