Abstract: Lithofacies and Geodynamic Development of the Magura Flysch in the Northwest Part of the West Carpathians (Czech Republic)

KREJCI, OLDRICH, M. BUBIK, J. FRANCU, J. SIKULA, and F. HUBATKA

The Magura Flysch forms a complex nappe structure of the Outer West Carpathians overlying the eastern margin of the Bohemian Massif. Density-balanced cross-sections of the upper crustal layer along selected seismic profiles were constructed based on the analysis of frequency characteristics of seismic and gravity data. Tectonic elements in the crystalline complexes, overlying sedimentary and overthrust units were traced and interpreted in respect to the Alpine orogeny and deformation.

Partial slices within nappes were correlated lithologically in the up to 6-km-deep borehole profiles using the well logs. New paleontological data on planktonic foraminifers and nannofossils provide improved stratigraphy and dating of the paleo-oceanographic events.

Geochemistry of organic matter and clay minerals gives evidence of variations in the sedimentary environments in the Magura basin and suggests deeper burial prior to formation of the final tectonic structure. Maturity data suggest that the main source rocks reached the oil and gas generation.

Based on the basin analysis the principal phases of evolution are described: the Magura basin opened in the Jurassic/Lower Cretaceous, deposition continued up to the Lower Oligocene. The deformations begun in the Eocene and the final nappe structure formed in the Lower Miocene.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria