Paleoenvironment of the eastern Tethys in the early Paleocene

In the earliest Paleocene at least three intervals of erosion or nondeposition of sediments have been identified (K/T, P0/P1a, P1a/P1b boundaries) in addition to a black pyrite- and organic-rich clay layer about 1.5 to 3.0 m above the K/T boundary (Subzone P1b/P1c, upper Chron 29N). These hiatuses appear to be widespread and correlate with global sea level fluctuations. Danian planktic foraminiferal assemblages of the eastern Tethys are dominated by alternating abundance maxima between triserial (Guembelitria) and biserial (Woodringina, Chiloguembelina) species. Biogeographic distribution of these taxa indicates that both groups thrived in shallow continental shelf regions. Moreover, abundance maxima of triserial taxa seem to correspond to δ¹³C depletion intervals, which indicate low surface productivity, whereas abundance maxima of biserial taxa correspond to enriched δ¹³C intervals which imply high surface productivity. -from Authors