Tracing the source of ancient reworked organic matter delivered to the North Atlantic Ocean during Heinrich Events

A major effort of the geochemical and paleoclimate community has been to identify the specific sources of the ice-rafted debris (IRD) in Heinrich Layers (HLs). Although the general consensus is that the majority of the IRD originated from the Hudson area of northern Canada, the specific sources are...

Full description

Bibliographic Details
Published in:Geochimica et Cosmochimica Acta
Main Authors: Hefter, Jens, Naafs, B. David A., Zhang, Shunxin
Format: Article in Journal/Newspaper
Language:English
Published: 2017
Subjects:
Heinrich Layer
Biomarker
Organic geochemistry
Hudson Strait
Ordovician source rock
Paleozoic
Baffin Island
Canada
Hudson
Baffin
Ice Sheet
Labrador Sea
North Atlantic
Online Access:https://hdl.handle.net/1983/60f5b109-a19c-4c87-8a20-993861565535
https://research-information.bris.ac.uk/en/publications/60f5b109-a19c-4c87-8a20-993861565535
https://doi.org/10.1016/j.gca.2017.02.008
https://research-information.bris.ac.uk/ws/files/103938801/Submitted_Manuscript.pdf
https://research-information.bris.ac.uk/ws/files/106554471/mmc1.pdf
Description
Summary:A major effort of the geochemical and paleoclimate community has been to identify the specific sources of the ice-rafted debris (IRD) in Heinrich Layers (HLs). Although the general consensus is that the majority of the IRD originated from the Hudson area of northern Canada, the specific sources are not well constrained. Here we compare the diagnostic organic geochemical signature of HLs to that of a number of Paleozoic outcrops across the former margin of the Laurentide ice sheet. We show that the biomarker signature of Upper Ordovician strata from Southampton and Baffin Island is compatible with that found in HLs in the Labrador Sea and North Atlantic, while the biomarker signature of other Paleozoic formations from the former margin of the Laurentide ice sheet is not. In addition to the biomarker signature, key-inorganic characteristics (δ18O, εNd, and 87Sr/86Sr ratios) of these formations from Southampton and Baffin Island are consistent with those reported from HLs. The location of these formations in and around the Hudson Strait is compatible with palaeo-ice flow regimes through the Hudson Strait, allowing for easy entrainment and rapid transport to the ocean. Based on these results we propose that these specific Upper Ordovician formations form a main source of IRD in HLs and hence infer an active role of the Hudson Strait paleo-ice flow in these events.

Similar Items