Neogene and Quaternary structural development of the Orava Basin in the light of geological, geomorphological and remote sensing studies

Monika Chrustek

University of Science and Technology AGH

Faculty of Geology, Geophysics and Environmental Protection

Cracow, Poland

[email protected]

The Orava Basin was formed during the Neogene times between Inner and Outer Carpathians and was enlarged in its NE part during the Quaternary. Because of its rhomboidal outline, a pull-apart mechanism was proposed for the Orava Basin in the 1990s. However, the margins and internal basin architecture is still widely unknown.

On the digital elevation model are recognisable several groups of lineaments, which are reflection of dislocations in the base of basin and geological units bordering this basin. The NNW-SSE lineaments which reflect oblique faults are along the south and north fringes of the basin. Geometrical model of these faults suggests that they are rotated faults orientated previously at high angles to the regional shear couple situated between Inner and Outer Carpathians. It is rotated system of conjugate Rider (R’) shears formed in transpressional regime. Some of NNE-SSW lineaments were interpreted as thrust lines. A set of longitudinal faults occurs under Neogene and Quaternary deposits and was detected in the geophysical cross-sections. These faults make up fringes of the basin and were formed in extensional processes.

To complement the digital elevation model’s analysis, interpretation of the aerial pictures, geological research of mezostructures and analysis of rivers net in the study area will be conducted. They are very important data, which will help to explain the tectonic process sequences and surface and subsurface tectonic structure of the pull-apart basin. Besides, these data could distinguish existence, distribution and geometry of possible traps for hydrocarbons and aid exploration effort.

AAPG Search and Discovery Article #90060©2006 AAPG Foundation Grants-in-Aid