April S. Dalton
Pollen and macrofossil-inferred palaeoclimate at the Ridge Site, Hudson Bay Lowlands, Canada: evidence for a dry climate and significant recession of the Laurentide Ice Sheet during Marine Isotope Stage 3
Dalton, April S.; Väliranta, Minna; Barnett, Peter J.; Finkelstein, Sarah A.
Authors
Minna Väliranta
Peter J. Barnett
Sarah A. Finkelstein
Abstract
We examine pollen, macrofossils and sedimentological proxies from the Ridge Site, an 18‐m sequence of glacial and non‐glacial sediments exposed along the bank of the Ridge River in the southern Hudson Bay Lowlands (HBL), Canada. As the HBL is located in the previously glaciated region of North America, palaeorecords from this region have important implications for understanding ice‐sheet palaeogeography and climate for the late Pleistocene. Two diamicton units were interpreted as subglacial till deposited by a glacier flowing toward the south‐southwest (lower diamicton) and west‐southwest (upper diamicton), respectively. Confined between these tills is a 6‐m non‐glacial unit, constrained to Marine Isotope Stage 3 (MIS 3; c. 57 000 to c. 29 000 a BP) by three radiocarbon dates. Quantitative analyses of the pollen record (dominated by Sphagnum, Cyperaceae, Pinus, Picea, Salix, Alnus and Betula) suggest that average summer temperature (June, July, August) was 14.6±1.51 °C, which is similar to that of the present day at the site. Total annual precipitation was 527±170 mm as compared to 705 mm present‐day. The macrofossil record confirmed the local presence of Betula, Salix and conifers. Our results, in combination with other records from the periphery of the Laurentide Ice Sheet, suggest that vast boreal forest‐type vegetation, along with a drier interstadial climate, existed in the region during MIS 3. We also compare pollen‐derived palaeoclimate reconstructions from the Ridge Site with reconstructions from a previously published site along the Nottaway River, HBL, which was dated to MIS 5a–d (c. 109 000 to c. 82 000 a BP). This comparison suggests that, with additional data, it may be possible to differentiate MIS 3 and MIS 5 deposits in the HBL on the basis of relative continentality, with MIS 3 characterized by lower total annual precipitation, and MIS 5 by values similar or greater than present‐day.
Citation
Dalton, A. S., Väliranta, M., Barnett, P. J., & Finkelstein, S. A. (2017). Pollen and macrofossil-inferred palaeoclimate at the Ridge Site, Hudson Bay Lowlands, Canada: evidence for a dry climate and significant recession of the Laurentide Ice Sheet during Marine Isotope Stage 3. Boreas: An International Journal of Quaternary Research, 46(3), 388-401. https://doi.org/10.1111/bor.12218
Journal Article Type | Article |
---|---|
Acceptance Date | Oct 30, 2016 |
Online Publication Date | Dec 14, 2016 |
Publication Date | Jul 1, 2017 |
Deposit Date | Jun 20, 2018 |
Publicly Available Date | Aug 14, 2018 |
Journal | Boreas |
Print ISSN | 0300-9483 |
Electronic ISSN | 1502-3885 |
Publisher | Wiley |
Peer Reviewed | Peer Reviewed |
Volume | 46 |
Issue | 3 |
Pages | 388-401 |
DOI | https://doi.org/10.1111/bor.12218 |
Files
Accepted Journal Article
(24.3 Mb)
PDF
Copyright Statement
This is the accepted version of the following article: Dalton, April S., Väliranta, Minna, Barnett, Peter J. & Finkelstein, Sarah A. (2017). Pollen and macrofossil-inferred palaeoclimate at the Ridge Site, Hudson Bay Lowlands, Canada: evidence for a dry climate and significant recession of the Laurentide Ice Sheet during Marine Isotope Stage 3. Boreas 46(3): 388-401, which has been published in final form at https://doi.org/10.1111/bor.12218. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
You might also like
The configuration of Northern Hemisphere ice sheets through the Quaternary
(2019)
Journal Article
Widespread global peatland establishment and persistence over the last 130,000 y
(2019)
Journal Article
Was the Laurentide Ice Sheet significantly reduced during Marine Isotope Stage 3
(2019)
Journal Article
Downloadable Citations
About Durham Research Online (DRO)
Administrator e-mail: dro.admin@durham.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search