Micropaleontological and Isotopic Perspective of Surface Water Mass Variability in the NE Atlantic from MIS 6 to 5e (188 to 115 ka)

The penultimate glaciation (marine isotope stage (MIS) 6) is considered regionally extreme compared to the last glacial maximum, in which European ice sheets had a vast areal extent. In contrast deglaciation (19–7 ka), (140–130 ka) hosts one of most rapid oceanographic changes late Pleistocene. this study, we reconstructed near-surface and thermocline central northeast Atlantic by analyzing sediments from two Integrated Ocean Drilling Program Expedition 306 sites. Sites U1313 (41°00.6′ N, 32°57.4′ W) U1314 (56°21.9′ 27°53.3′ were drilled on eastern flank mid-Atlantic ridge Gardar Drift subpolar North Atlantic, respectively. We analyzed planktonic foraminiferal assemblages, ice-rafted debris (IRD), oxygen isotopes foraminifers, Globigerina bulloides, Globorotalia inflata, MIS 6 5e (185–115 ka). Warmer colder sea-surface conditions marked change relative abundance polar, subpolar, transitional foraminifers. Oxygen G. bulloides inflata suggest that deepened at subtropical Site during 6. lack prevented us profiling mixed layer U1314. 6, re-stratified interglacial. major IRD events both sites suggests stability Laurentide sheet subsequent glaciation. presence Heinrich event 11 indicates discharge freshwater freshened sea surface, resulting mixing between thermocline. Our results placed into broader context using published data shed light sensitivity following with transition an interglacial period surface circulation.