Abstract: Pre-orogenic Evolution of the Polish Part of the Outer Carpathians-Quantitative Subsidence and Uplift Analysis

POPRAWA, PAWEL, and TOMASZ MALATA,

The Outer Carpathians form an orogen where flysch-dominated primary basin-fill is detached from basement, folded and thrust over the European Platform.

Synthetic profiles of the basin-fill were reconstructed, covering Berriasian-Early Miocene basin history record at most. The profiles were analyzed using backstripping technique to determine history of vertical movements of the primary basement of the Outer Carpathian basin. The rates of sedimentation were analyzed to reconstruct general vertical movements of source areas.

The results shows relatively slow tectonic subsidence for Early Cretaceous interpreted to result from thermal cooling after possible earlier (Late Jurassic?) extensional tectonic event. Since Turonian to Coniacian, an uplift of several hundreds meters took place over the basin. It is interpreted as an effect of change in tectonic regime, into compression, resulting from Inner Carpathian folding, Carpathian foreland inversion. During Late Paleocene subsidence was re-established and lasted until Middle-Late Eocene, ceasing with time. Since Late Eocene, rapid uplift of a few thousand meters started and continued until Early Oligocene. This major uplift was followed by limited Oligocene-Early Miocene subsidence, predating shift of shortening to the north. The uplift is suggested to result from rapidly increasing compressional stress, and minor subsidence resulted from stress relaxation after relocation of main detachment surfaces. Further continuation of plate (microplate) convergence introduced orogenic processes into the analyzed area.

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