A petrographic and sedimentologic analysis of clasts in the Kr??a Breccia of the Malé Karpaty Mountains (Western Carpathians, Slovakia)

摘要

A section which runs through the Kr??a Breccia, known as the significant ?Upper Cretaceous-Paleocene paleokarst phenomenon, and its contact with the Lower Eocene Jelenia hora Formation in the Malé Karpaty Mts., yield data on the source area of the clasts, paleotectonic settings during the breccia formation, and determine the age of the transgression onset. Analyses of the red clay matrix and the clasts support the idea that the source area of the clasts was situated nearby, and its erosive base did not erode the older formations than the Upper Permian. The breccia bodies fill karstic depresions in the Middle Triassic limestones of the Gutenstein Formation; the eroded material has been mostly derived directly from this formation. The rest of the clasts is represented by siliciclastic material transported from a distant source. The breccia infillings of the karst relief are covered with Paleogene basal marine transgressive facies rich in larger benthic foraminifera, which provide biostratigraphic data on the time of the breccia formation.