Late quaternary (stage 2 and 3) meltwater and heinrich events, northwest labrador sea

Two major meltwater events are documented in cores from the NW Labrador Sea. One occurred ca. 20,000 ¹⁴C yr B.P. in association with deposition of a major detrital carbonate unit. Both prior to and after this event, δ¹⁸O values of near-surface planktonic foraminifera were 4.5%, indicating fully enriched glacial values. A younger event (ca. 14,000 ¹⁴ C yr B.P.) is characterized by a dramatic change in δ¹⁸O from 4.5 to 2.0% and coincided with the retreat of ice from the outer SE Baffin Shelf, possibly into Hudson Strait. These meltwater events coincide with Heinrich (H) layers 1 and 2 from North Atlantic sediments. The 14,000 ¹⁴C yr B.P. meltwater event indicates that the eastern margin of the Laurentide Ice Sheet also underwent rapid retreat at approximately the same time as other ice sheet margins around the NE North Atlantic. A third major detrital carbonate event at the base of HU87-033-009, possibly correlative with Heinrich layer 3, occurred ca. 33,960 ± 675 ¹⁴ C yr B.P.; however, this is older than the accepted date for H-3 of 27,000 ¹⁴C yr B.P. and may be H-4.