engleski

GEOLOGICAL EVOLUTION OF DINARIC KARST REGION

Dinaric region is a geographical term that comprises NW part of the Balkan peninsula, while Dinaric karst (“Classical karst”) cover its SW part (approx. 800 km long and 200 km wide area). Geologically or tectonically, Dinaric karst comprises mostly External Dinarides along with NE part of the Adriatic foreland, and is partly submerged during Holocene under the Adriatic Sea.Geological and tectonic evolution of the wider Adriatic region is related to a regional geotectonic unit Adriatic microplate or Adria (cf. Chanell et al. 1979) that has been formed during Permian to Triassic rifting phase of Pangea, when it developed between Eurasia and Gondwana (Africa). Interaction of the Adria with another (micro)plates in the region, had a crutial role in Mesozoic to Cenozoic geological evolution of the area. The model of Korbar (2009) consider significant shorthening, since Dinaridic units overthrust Adriatic ones for approx. 50 km on the representative profile. NEAT (NW equivalent of BCB) is just compressed below the overthrust. Since Adria is still moving north for 3-5 mm/year, this is rather accomodated by vertical thick-skinned tectonic transport.There are also models that consider minor shorthening during tectonic evolution of the External Dinarides (e.g.Pamić et al. 1998). Interestingly, here in SW Slovenia, thrust and nappe tectonic is evident (e.g. Placer, 1981) implying significant shortening during thin-skinned phase of the orogenesis. Further on SE, in Croatia, thrusts are masked by younger thick-skinned and the latest strike-slip tectonic.Present day microplate configuration below wider Adriatic region is reconstructed according to P-wave tomography images from deep geosphere (Piromallo & Morelli, 2003). It revealed picture of two microplates: SE Adria and NW Adria, deepening in different directions.This, combined with active tectonics in Adriatic foreland (extension and diapirism), along with GPS data which also suggest Adriatic microplate fragmentation (Oldow et al. 2002), and latest seismic data on hypocenter transversal alignments (Bechtold et al. 2009), imply that recent, still undefined tectonic re-organization characterizes wider Adriatic region.

Adria, Alpine orogenesis, External Dinarides, Adriatic foreland, tectonostratigraphy

nije evidentirano