The Oxfordian in the south-western margin of the Holy Cross Mts

Abstract

The paper deals with the Oxfordian deposits cropping out along the south-western margin of the Holy Cross Mts, Central Poland. In the lithostratigraphic sequence of these deposits, seven members have been distinguished and chhracterized as to their lithology and facies development. The assemblage of ammonites, that comprises 106 taxa belonging to the families: Phylloceratidae,Lytoceratidae, Oppeliidae, Haploceratidae, Cardioceratidae, Perisphinctidae, and Aspidoceratidae, allows to recognize a sequence of successive biostratigraphic units. In the Lower Oxfordian, documented are the mariae and the cordatum Zone. In the Latter, the presence of the subzones bukowskii, costicardia, and cordatum is stated in the same range and ammonite content as commonly accepted in Europe. In the Middle and Upper Oxfordian, submediterranean zones: plicatilis, transversarium, bifurcatus, and bimammatum, have been recognized. The latter zone in the investigated area is for the first time documented by ammonites. In the paleontological part of the paper, some new forms, and those, the stratigraphic range of which is different from that hitherto known, are described and discussed.