Palinoflora i plankton paleogeński z NW Polski

Abstract

PALEOGENE PALYNOFLORA AND PLANKTON IN NORTH-WESTERN POLAND Summary Spore-pollen-plankton analysis comprised sediments from 5- drillings in north-western Poland. The analysis made it possible to differentiate the upper Paleocene (boreholes Szczecin IG-I, Goleniów IG-I and Goleniów IG-2), varying in composition of floral assemblages from individual drillings. The Upper Paleocene is characterized by an assemblage of the Paleocene type as well as very small number of Gymnospermae pollen and predominance of triporate grains. including Normapolles. An assemblage transitional between the Paleocene and Eocene ones was found in the borehole Kąty 4P/IG and the Lower Eocene assemblage - in the boreholes Goleniów IG-2 and Trzebież 2T/IG. The assemblages are characterized by an increase in share of Gymnospermae pollen without sacci, tricolpate and tricolporate grains and, at the same time, disappearance of the Normapolles group. Marine influences are reflected by the presence of plant microplankton, mainly Dinoflagellatae. Fairly good development of vegetational cover in this area in the Middle Eocene resulted in origin of brown coal layers (boreholes Szczecin IG-I and Goleniów IG-2). Spectrum obtained for these sediments is characterized by disappearance of the Normapolles group, predominance of Angiospermae pollen, marked share of Gymnospermae pollen grains without sacci, and fairly high share of various species of spores. The Upper Eocene (borehole Szczecin IG-1) is primarily evidenced by marine plant microplankton. Lower Oligocene assemblage (previously regarded as the Middle Oligocene), found in the boreholes Szczecin IG-I and Goleniów IG-2, reflects development of forests of various species of Gymnospermae and the vegetation with grains of tricolpate and tricolporate pollen, mainly in coastal zone open reservoirs with marine microplankton with Dinoflagellatae.