Tracking sediment delivery to central Baffin Bay during the past 40 kyrs: Insights from a multiproxy approach and new age model

Abstract

Reconstructing former ice sheet history and glaciogenic sediment fluxes surrounding Baffin Bay during and since the Last Glacial Maximum (LGM) is a major scientific challenge. Here, a new multi-proxy analysis of sediments from a central Baffin Bay (BB) sediment core reveals two dominant sediment/discharge sources: 1) a detrital carbonate (BBDC; dolomite-rich) source that represents increased discharge from the NE Laurentide Ice Sheet (LIS) and southern Innuitian Ice Sheet (IIS), and 2) a radiogenic, felsic provenance likely from a west Greenland Ice Sheet (GIS) source, although a contribution from the Baffin Island LIS cannot be ruled out. By utilising a new method for radiocarbon calibration in high latitude polar environments we provide updated age constraints on BBDC1 (14.1–13 cal ka BP) and BBDC0 (12.0–10.9 cal ka BP). This coupled with our sediment analysis shows the BBDC layers to be coincident with the Bølling-Allerød (BBDC1) and the recovery from the Younger Dryas (BBDC0). The timing of BBDC1 also further supports the theory of an ice shelf covering northern Baffin Bay from the LGM and during initial deglaciation.