Biostratigraphy of the Old Paleozoic carbonates in the Zawiercie area (NE margin of the Upper Silesian Coal Basin)

Results are presented of biostratigraphic investigations of Old Paleozoic carbonate sediments from 6 boreholes of the Zawiercie area. Deposition of carbonate sediments had begun in this area probably in Arenig. An assemblage of microfauna traced in borehole samples consists mainly of conodonts and documents sediments of the Lower, Middle and Upper Ordovician and Lower Silurian.