ŚRODOWISKA SEDYMENTACJI I PALINOFACJE KREDY DOLNEJ W KILKU OTWORACH WIERTNICZYCH CENTRALNEJ POLSKI

Abstract

LOWER CRETACEOUS SEDIMENTARY ENVIRONMENTS AND PALYNOFACIES IN SOME BOREHOLES OF CENTRAL POLANDAbstract. The paper presents a preliminary recognition of sedimentary environments and palynofacies in Lower Cretaceous deposits of the Sarnów IG 1, Wągrowiec IG 1 and Poddębice PIG 2 boreholes of central part of the Polish Lowland, central Poland, based on lithological and sedimentological investigations.Adetailed analysis of palynological spectrum included determination of the contents of plankton (in relation to total frequency of palynomorphs), phytoclast in total kerogen, and organic matter. Palynological data were subsequently correlated with the results of sedimentological logging of drill cores, as well as with lithological observations and overall palaeogeographical research. Based on the material analysed, and referring to the identified palynological spectrum, the following sedimentary environments have been distinguished in the Lower Cretaceous sections: 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, and presumed barrier and shallow-marine embayment. A maximum flooding surface has been identified in the Poddębice PIG 2 section, represented by a thin dark-grey marl bed which seems to be dated at the Berriasian/Lower Valanginian transition. The investigations are the first, preliminary approach to the problem of relationship between palynofacies and sedimentary environments in the Lower Cretaceous of Poland.