Late Pleistocene chronology, palaeoecology and stratigraphy at a suite of sites along the Albany River, Hudson Bay Lowlands, Canada

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Dalton , A S , Finkelstein , S A , Barnett , P J , Valiranta , M & Forman , S L 2018 , ' Late Pleistocene chronology, palaeoecology and stratigraphy at a suite of sites along the Albany River, Hudson Bay Lowlands, Canada ' , Palaeogeography, Palaeoclimatology, Palaeoecology , vol. 492 , pp. 50-63 . https://doi.org/10.1016/j.palaeo.2017.12.011

Title: Late Pleistocene chronology, palaeoecology and stratigraphy at a suite of sites along the Albany River, Hudson Bay Lowlands, Canada
Author: Dalton, April S.; Finkelstein, Sarah A.; Barnett, Peter J.; Valiranta, Minna; Forman, Steven L.
Contributor: University of Helsinki, Ecosystems and Environment Research Programme
Date: 2018-03-01
Language: eng
Number of pages: 14
Belongs to series: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
URI: http://hdl.handle.net/10138/312552
Abstract: Stratigraphic records from formerly glaciated regions are critical for detailed study of the timing, onset and dynamics of past ice sheets and the palaeoecology of previous ice-free intervals. We examined three stratigraphic sections from an 18-km stretch of the Albany River, Hudson Bay Lowlands, Canada, located at the geographic center for many Late Pleistocene ice sheets. Till characterization and correlation suggest that at least three glacial advances from shifting ice centers within the Labrador sector of the Laurentide Ice Sheet were preserved in these stratigraphic records. Non-glacial units (fluvial, organic-bearing sediments) were constrained via optically stimulated luminescence to two possible periods at ca. 73,000 to 68,000 yr BP and ca. 60,000 yr BP. Boreal and peatland taxa (Picea, Pinus, Poaceae, Betula, Cyperaceae, Sphagnum) dominated the pollen record at each site, whereas plant macrofossils analyzed at one site confirm the local presence of conifer trees (bark, needles, seed wings), bryophytes (largely Scotpidium spp), herbaceous plants (Caryophyllaceae, Carex, Poaceae), and an aquatic setting (e.g. Potamogeton, ephippia of Daphnia spp). Pollen-derived average summer temperature reconstructions suggested that local temperatures at the Albany sites were between 12 and 15 degrees C, which is similar to present-day estimates for the region (14.2 degrees C). Reconstructed annual precipitation estimates were 580-640 mm, which is similar to slightly higher than present-day estimates (564 mm). Non-glacial intervals at the Albany sites likely represent abandoned fluvial environments that supported water-logged peatland biota. Results from this research contribute toward ongoing efforts to constrain ice sheet dynamics over North America during the last glacial cycle (e.g. 71,000-14,000 yr BP) and provide insight into the complex Late Pleistocene palaeoclimate record at the innermost area of the glaciated region.
Subject: Modern analogue technique
Pollen
Macrofossils
Optically stimulated luminescence
MIS 3
MIS 5
Pre-LGM
Wisconsinan stage
LAURENTIDE ICE-SHEET
MARINE ISOTOPE STAGE-3
SEA-LEVEL
GLACIAL HISTORY
NORTH-AMERICAN
CARBON ACCUMULATION
EASTERN CANADA
MIS 5C
AGE
MANITOBA
1171 Geosciences
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