Stratigraphy of the Devonian in the Szwejki IG 3 deep well, Central Poland

Abstract

Detailed biostratigraphic investigations of conodonts and ostracods indicate the presence of the late Eifelian kockelianus Zone in the lower part of the Devonian sequence. Its upper portion has been ascribed to the earliest Frasnian (not older than the upper part of the falsiovalis Zone). However, boundaries of the Givetian have not been precisely defined due to a poor biostratigraphic control. The studied section reveals many similarities to the development of the Devonian succession in the northern Łysogóry Region (Holy Cross Mts.) located ca. 90 km to the south-east. Both the sequences display similar litho- and biofacies development and comparable thicknesses of the chronostratigraphic units.