Fault Tectonics of the Carpathian Foredeep During Mesozoic-Cenozoic Time

Andrew M. Bubniak
Institute of Geology and Geochemisty of Fossil Fuels, National Academy of Sciences, Lviv, Ukraine

 This paper integrates structural geological, geohistory, and geomophological studies in order to address some unsolved questions: (1) the time of the formation faults of the basement of the Ukrainian Carpathian foredeep; (2) relationship between faults in the basement to those in the foredeep: (3) history of faults dynamics; and (4) the influence of faults on the morphology of the area. The analysis of curves of tectonic subsidence and rates of sedimentation show various phases of activity on faults in the basement and in the foredeep. The greatest activity is seen on Carpathian foredeep faults during Sarmatian time. Some of the faults of the Carpathian foredeep are growth faults other faults are inherited. Structural investigations at regional and local scales show the evolution of stress fields which formed the faults. Kinematic data were sampled along three profiles crossing the Outer Carpathians and the Inner and Outer zone of the foredeep. Slickensides, including striations, small faults, folds, and joints were measured, for use in paleostress analysis. Geomorphic studies show the influence of faulting on the topography. Regional fault structures are especially well defined topographically. The results have been used to model the fault tectonics of the Carpathian foredeep during Mesozoic – Cenozoic time. On a Jurassic - early Cretaceous passive continental margin faults were formed in an extensional regime. Late Cretaceous to Oligocene inversion was caused by compression. The faults in the Carpathian foredeep formed as a result of flexure in the foreland basin. Neotectonic modification of the faults after the early Sarmatian resulted from the final deformation of the Carpathian mountains and the foredeep.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005