The Xiamen Symposium on Marine Environmental Sciences (XMAS 2025)

1438 / 2024-09-27 10:14:23

Palaeoredox reconstruction in the Bay of Bengal since the Miocene

Bottom water oxygenation;,Redox sensitive elements,Bay of Bengal,Miocene

The Miocene Epoch is proposed as a key interval in climate transition, which promoted a series of environmental evolutions. However, the relative changes in deep-sea redox conditions and its response to the climate transition remain unclear through the Miocene. Reconstruction of paleo-redox conditions in a well-dated sediment core, covering the Miocene, collected from the Bay of Bengal, has been made based on redox-sensitive element geochemistry and metal stable isotopic signatures. Our findings reveals that the water column in the Bay of Bengal was oxic to suboxic during the Oligocene and middle Miocene while oxic condition prevailed during the late Miocene and Pliocene. Combined with the changes in local primary productivity and deep-water circulation, we argue that the varying oxygenation evolution trends are probably related to the change in water mass structure driven by climate change.