Abstract: Implications of geological development on hydrocarbon prospectivity of Moravia (Czech Republic)

STRANIK, Z., J. FRANCU, P. HANZL, O. KREJCI, J. OTAVA, E. STRELCOVA, R. BRZOBOHATY, N. DOLAKOVA, S. HLADILOVA, J. KALVODA, S. NEHYBA, A. PRICHYSTAL

New geological research in Moravia resulted in significant changes in the understanding of geologic history of this geologically unique region where in an area 100 X 200 km2 converge Hercynian and Alpine Orogens. Both are underlain by Cadomian basement (Brunovistulicum) consisting mainly of magmatic rocks of Brno and Dyje massifs enveloped by metamorphic cover. The Brno massif is composed of two slightly different Cadomian granitoid bodies of calc-alkaline affinity separated by low-grade metamorphosed volcanic rocks of MORB composition.

The Brunovistulicum is interpreted as the continuation of the Eastern Avalon terrane which includes London-Brabant Massif and Upper Silesian block, all involved in the collision with Baltica at the Silurian-Devonian boundary. During the Hercynian orogeny the Brunovistulicum acted as a buffer zone with colliding southern perigondwanian terranes. Tectonically convergent Devonian and Carboniferous carbonate and flysch sequences are remnants of different subbasins developed on the Brunovistulican passive margin.

Alpine orogen is represented by overthrust of West Carpathian flysh over Cadomian and Hercynian basement and overlying autochthonous Mesozoic and Tertiary and partly over its Miocene foredeep. Flysh sequence originated as accretion prisms during subduction of the European continental plate under Alpine-Carpathian-Pannonian block in late Cretaceous to early Miocene. Tectonic position of the fronts of the nappes documents motion of overthrust to NW with nappes becoming younger toward NE. Autochthonous Mesozoic and Tertiary rocks appear to be the most promising for hydrocarbon interests.

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