Palynology of the upper Visean Paprotnia Beds (Bardo Unit, Polish Sudetes)

Abstract

The siliciclastic rocks of the Paprotnia Beds from the Bardo Unit (Polish Sudetes) provide abundant and diverse palynological material. The miospore assemblages recovered allow distinction of two miospore biozones. The Tripartites vetustus–Rotaspora fracta (VF) Biozone was recognized in the lower and the middle parts of the section. In its upper part the Cingulizonates capistratus (Cc) Subbiozone, the lower part of the Cingulizonates capistratus–Bellispores nitidus (CN) Biozone was distinguished. These results indicate that the rocks of the Paprotnia section, considered earlier on the basis of biostratigraphic and radiometric data as upper Asbian, should be assigned to the upper Asbian and Brigantian. The location of the Asbian/Brigantian boundary and the possible occurrence of a gap in the Brigantian part of the section are discussed. Palynofacies observations of miospore preservation and frequency provided additional information, which confirm the gradual shallowing of the environment of deposition from offshore to onshore. Thermal maturity assessment of organic matter, based on miospore colour, indicates early mature and mature stages of organic matter thermal alteration.