The palynofacies pattern for the Lower Cretaceous of central Poland

Sedimentary environments and palynofacies were identified in the Lower Cretaceous of central Poland. The study was based on lithological observations, sedimentological logging and palynological investigations in eleven boreholes. Palynological observations included primarily identification of the proportions, variability and features of individual components of palynological matter. The results were correlated with sedimentological, lithofacies and palaeogeographical data. Sedimentary environments and palynofacies were analysed in the vertical section, and spatially in different areas: in the central basin area, in the carbonate-clastic deposition zone, in the transitional zone (deltaic sedimentation) and in a zone of an active salt pillow. The following sedimentary environments were identified in the Lower Cretaceous: upper shoreface and lower-middle shoreface with transitions to an offshore-open-marine shelf, delta (?delta front) passing up into distributary channel fills on a delta plain, presumed barrier and shallow-marine embayment, lagoon and shallow carbonate-siliciclastic shelf. In case of the absence of diagnostic features for exact determination of sedimentary environments, they were defined as generally marine or transitional (probably deltaic). A maximum flooding surface has been identified in the Poddebice PIG 2 section, represented by a thin dark grey marl bed which is dated approximately at the Berriasian/Lower Valanginian transition. The relationships between sedimentary environments and the characteristics of the palynofacies spectrum were determined, and a palynofacies pattern for the Lower Cretaceous of central Poland has been proposed.