Calcareous nannofossil assemblage

sea-level reconstruction

This assemblage records a complete transgression-regression cycle during the PETM, enabling inter-regional correlation in the eastern Tethys.

Wang, Xuejiao · Xi, Dangpeng · Mattioli, Emanuela · Guannan, Wang · Wan, Xiaoqiao

Palaeogeography, Palaeoclimatology, Palaeoecology 2023

Advantages

Dated sea-level cycle

The transgression is dated to zones NP7-9a, the highstand coincides with increasing Discoaster spp., and the regression corresponds to low abundance and diversity in NP10-11.

Key bioevents

First occurrences of H. riedelii and D. multiradiatus and the RD assemblage are recorded, enabling correlation across the eastern Tethys.

Inter-regional correlation

Correlation between the two sections indicates the highest relative sea level in the Tianshan Mountain area occurred near the middle part of NP9a.

Applications

• paleoceanography：Provides evidence of eastern Tethyan sea-level changes and biotic response.
• paleoclimate reconstruction：Links sea-level cycles to the PETM climate event.
• stratigraphic correlation：Calibrates strata using nannofossil zones for correlation.