Age determination of Paleogene sediments from the Prysz Bay

Strontium isotopic analyses of small mollusk remains found within these diamictites, however, yield younger ages ranging from 29 to 23 Ma (i.e., latest early Oligocene to earliest Miocene).

These age discrepancies could be caused by repeated glacial reworking of microfossils, macrofossils, and sediment clasts through the late Oligocene or, alternatively, by ion exchange in the still aragonitic mollusk shells.