Carbonate saturation dynamics during the Paleocene-Eocene thermal maximum: Bathyal constraints from ODP sites 689 and 690 in the Weddell Sea (South Atlantic)

► We provide added constraints on lysocline movement in Southern Ocean during PETM. ► First 36 ka of PETM are captured by the Site 689 record. ► Lysocline initially shoaled to depths shallower than Site 689 (~ 1,100 m). ► Site 689 PETM section is much thicker than correlative part of Site 690 section. ► Carbonate sedimentation recovered earlier at Site 689 than at deeper Site 690.