Opoka – a mysterious carbonate-siliceous rock: an overview of general concepts

The opoka is a carbonate-siliceous marine sedimentary rock, forming thick succession of Upper Cretaceous age in Poland and other regions Europe. This rock has been studied for over 150 years, but only the use modern analytical techniques enables formulation its mineralogical definition, which identifiesthe distinct features allows it to be distinguished from rocks (e.g. chalk, gaize). Parallel petrographic research on opoka, palaeobathymetric interpretations, were based palaeotectonic models Danish-Polish Trough inversion revised. Depending model history, interpreted as deep-water or shallow facies, without detailed studies composition. paper presents various aspects including history term, nomenclature, composition, microtexture palaeoecological significance opoka. New data permit precise definition this composition are discussed light reconstructions, bathymetry existing distribution.