Fazies und Ablagerungsraum der Pinczow Kalke (Mittleres Miozän, Heilig-Kreuz-Gebirge, Polen)

Abstract

Middle Miocene (Early Badenian) Pinczow Limestones are composed primarily of skeletal remains of red (coralline) algae, associated with the bryozoans and large foraminifers; they contain rich and diversified assemblage of fossils, impoverished, however, by the leaching of aragonitic skeletons. Four facies have been distinguished in the Pinczow Limestones, three of them on the basis of different algal growth forms, viz. rhodolith pavement facies, branching algae facies and algal-bryozoan facies (the latter with rhodoliths, branching and crustose thalli); the fourth facies is organodetrital. Two of these facies are comparable to the Recent Mediterranean analogues: the rhodolith pavement to “prâlines”, while the branching algae facies to “maerl”; possibly, also the initial stage of the coralligenous facies of the plateau occurs. Pinczow Limestones have formed under strong to moderate water agitation, at depths estimated as 30–80 m, on a carbonate platform deepening eastward. This is interferred from the red-algal and bryozoan growth-forms studies, the analysis of distribution of brachiopods, and actualistic facies comparisons. The observed succession of algal facies may reflect the ecological succession, starting from the colonisation of the bottom by branching algae, through the development of algal-bryozoan and rhodolith pavement facies, until final immobilisation of rhodoliths and initial installation of the coralligenous plateau.