882 / 2024-09-19 18:02:44
Preliminary glycerol dialkyl glycerol tetraethers results on the Norwegian Sea during PETM (Hole 1570D)
BrGDGTs,pH,PETM,Biomaker
Session 66 - Biomarkers in the sea: the tracers of key biogeochemical processes in the ocean’s past, present and future
Abstract Accepted
The ocean is an important reservoir of carbon, and the increase of carbon dioxide leads to ocean acidification. The Paleocene-Eocene Thermal Maximum (PETM, ~56Ma) is a typical example of abrupt climate change, increased carbon release, and ocean acidification. We report branched glycerol dialkyl glycerol tetraethers (brGDGTs) data from IOPD 396’ s Hole 1570D/1569A in the Norwegian Sea of the North Atlantic, located within the Northeast Atlantic Igneous Province, where early volcanic activity was one of the triggers for the PETM. Our results show that brGDGTs in 1570D are major terrigenous input. Meanwhile, The increase of brGDGTs and isoGDGT concentration, the reduced branched/isoprenoid tetraether (BIT) and ∑IIIa/∑IIa shows marine in situ GDGTs input during PETM, and the MBT'5ME-MAT inconsistent with MAT of Arctic continents, but the trend of MBT'5ME-T consistent with those of thermocline water temperature(TWT) and bottom water temperature (BWT), this raises the question of whether the MT indicates seawater temperature. The CBT'5me-ring increases while the MI decreases during the PETM, which still requires more data for further explanation. However, the data of GDGTs from 1569A and n-alkanes with compound-specific isotope from 1570D will come up soon, more work is needed to refine and interpret this interesting phenomenon.