Stratygrafia mikropaleontologiczna dolnej kredy w Polsce, bez Karpat

Abstract

MICROPALAEONTOLOGlCAL STRATIGRAPHY OF THE LOWER CRETACEOUS IN POLAND EXCLUDING THE CARPATHlANS

On the basis of investigated material, the author distinguishes in the Lower Cretaceous, excluding the Carpathians, the following stages and substages the Infravalanginian, corresponding to the zone with Subcraspedites and Riasanites, the Valanginian, coresponding to the zone with Polyptychites hoplitides, - and the Hauterivian, corresponding to the zone with noricus.

On the discussed area, the Infravalanginian is developed as a brackish or marine deposit. This marine Infravalanginian the author distinguishes from the deposits of the Lower Valanginian on the basis of its ammonite zones. The boundary between Infravalanginian and the Lower Valanginian lacks a distinct microfaunal definition.