KNR197-10CDH42 (Laurentian fan, Western North Atlantic) paleoceanographic data (Last Glacial Maximum)

DOI

Millennial scale events marked by the contribution of detrital sand are recorded in North Atlantic sediments during the Last Glacial Maximum (LGM), between Heinrich events (HE) 1 and 2, and left their imprint on Laurentian Fan (LF – 43◦N) sediments off eastern Canada. The LF counterpart of the wellknown detrital events consist of glacial red-brick sediments resulting from subglacial flows separated by olive-grey sediments appears at ∼21.4–19.9 and ∼19.5–18.65 cal kyr BP. High-resolution analyses of diatom assemblages and lithic grains coupled with planktonic oxygen isotopic records reveal that while the red sediment is almost barren of diatoms, foraminifera and lithics (>150 μm), they are abundant in the olive-grey sediment. Diatom assemblages reveal three phases during these events: (1) initial relatively warm/temperate conditions followed by (2) very cold surface water and drifting ice, and (3) a final phase characterized by relatively warmer waters and the appearance of detrital carbonate. Although these events possibly reflect the variability specific to the slope water region, they are likely the response to Atlantic Meridional Overturning Circulation perturbations and ice-sheet instability. Through a chain of mechanisms, meltwater inputs into the North Atlantic led ultimately to an increased volume of tropical waters and part of the heat stored in the subsurface was flushed by a brief convective episode that was not sustained, accounting for the return of cold conditions after the events. The sequence of mechanisms deduced from the paleo data here and elsewhere is consistent with previous modeling results. These data suggest that the detrital events between Heinrich event 1 and 2 may be synchronous across the North Atlantic, and that the LGM was probably not a time of prolonged steady state in the climate system.

Identifier
DOI https://doi.org/10.1594/PANGAEA.943366
Related Identifier https://doi.org/10.1016/j.epsl.2018.07.038
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.943366
Provenance
Creator Gil, Isabelle M ORCID logo; Keigwin, Lloyd D
Publisher PANGAEA
Publication Year 2022
Funding Reference Fundação para a Ciência e Tecnologia https://doi.org/10.13039/501100001871 Crossref Funder ID PTDC/AAC-AMB/108449/2008 https://app.dimensions.ai/details/grant/grant.3526213 Integration of proxy data from the North Atlantic for modelling climatic events - MONA; Fundação para a Ciência e Tecnologia https://doi.org/10.13039/501100001871 Crossref Funder ID SFRH/BPD/87718/2012 FCT postdoctoral fellowship; National Science Foundation https://doi.org/10.13039/100000001 Crossref Funder ID OCE-0822854 https://www.nsf.gov/awardsearch/showAward?AWD_ID=0822854 Radiocarbon Ventilation Ages and Climate in the Northern Subtropical Atlantic
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Resource Type Bundled Publication of Datasets; Collection
Format application/zip
Size 7 datasets
Discipline Earth System Research
Spatial Coverage (-54.756 LON, 43.465 LAT)