Chronology, Paleoecology and Stratigraphy of Late Pleistocene Sediments from the Hudson Bay Lowlands, Canada
Stratigraphic records in the Hudson Bay Lowlands (HBL), Canada, offer rare insight into local paleoenvironments and the Late Pleistocene climate system over North America. Age determinations on sub-till non-glacial materials suggest that the HBL, lying near the centre of the Last Glacial Maximum (LG...
Main Author: | |
---|---|
Other Authors: | , |
Format: | Thesis |
Language: | unknown |
Published: |
2017
|
Subjects: | |
Online Access: | http://hdl.handle.net/1807/80863 |
id |
ftunivtoronto:oai:localhost:1807/80863 |
---|---|
record_format |
openpolar |
spelling |
ftunivtoronto:oai:localhost:1807/80863 2023-05-15T13:10:20+02:00 Chronology, Paleoecology and Stratigraphy of Late Pleistocene Sediments from the Hudson Bay Lowlands, Canada Dalton, April Sue Finkelstein, Sarah A Earth Sciences 2017-12-19T00:02:25Z http://hdl.handle.net/1807/80863 unknown http://hdl.handle.net/1807/80863 Hudson Bay Lowlands Laurentide Ice Sheet Marine Isotope Stage 3 Pollen Quaternary 0653 Thesis 2017 ftunivtoronto 2020-06-17T12:08:35Z Stratigraphic records in the Hudson Bay Lowlands (HBL), Canada, offer rare insight into local paleoenvironments and the Late Pleistocene climate system over North America. Age determinations on sub-till non-glacial materials suggest that the HBL, lying near the centre of the Last Glacial Maximum (LGM) extent of the Laurentide Ice Sheet (LIS), was ice-free for parts of Marine Isotope Stage 3 (MIS 3; 57,000 to 29,000 yr BP), MIS 5 (130,000 to 71,000 yr BP) and MIS 7 (243,000 to 190,000 yr BP). The MIS 3 age assignment is notable since it suggests the possibility of significant retreat of the LIS and a relatively high global sea level, both of which are a contrast to assumptions that North America was moderately glaciated, and that global sea level was relatively low during that time interval. Paleoecological proxies, including pollen and plant macrofossils, suggest that the HBL contained peatland and boreal vegetation during all previous non-glacial intervals, and pollen-based quantitative reconstructions of sites which are hypothesized to be MIS 3 and MIS 5a (~80,000 yr BP) in age suggest that climate during MIS 3 may have had less annual precipitation than during MIS 5a and present day. Stratigraphic analyses of these glacial and non-glacial sediments provide insight into the dynamicity of Late Pleistocene ice sheets; multiproxy analyses of three stratigraphic successions along the Albany River resulted in the recognition of at least three glacial advances from shifting ice centers within the QuĂŠbec sector of the Laurentide Ice Sheet during the Late Pleistocene. This dissertation contributes a chronological dataset for reconstructing the movement, timing and dynamics of Late Pleistocene ice sheets over North America, as well as paleoecological data for understanding the character and distribution of boreal peatlands during previous interstadial and interglacial periods. Ph.D. Thesis Albany River Hudson Bay Ice Sheet University of Toronto: Research Repository T-Space Albany River ENVELOPE(-81.517,-81.517,52.283,52.283) Canada Hudson Hudson Bay |
institution |
Open Polar |
collection |
University of Toronto: Research Repository T-Space |
op_collection_id |
ftunivtoronto |
language |
unknown |
topic |
Hudson Bay Lowlands Laurentide Ice Sheet Marine Isotope Stage 3 Pollen Quaternary 0653 |
spellingShingle |
Hudson Bay Lowlands Laurentide Ice Sheet Marine Isotope Stage 3 Pollen Quaternary 0653 Dalton, April Sue Chronology, Paleoecology and Stratigraphy of Late Pleistocene Sediments from the Hudson Bay Lowlands, Canada |
topic_facet |
Hudson Bay Lowlands Laurentide Ice Sheet Marine Isotope Stage 3 Pollen Quaternary 0653 |
description |
Stratigraphic records in the Hudson Bay Lowlands (HBL), Canada, offer rare insight into local paleoenvironments and the Late Pleistocene climate system over North America. Age determinations on sub-till non-glacial materials suggest that the HBL, lying near the centre of the Last Glacial Maximum (LGM) extent of the Laurentide Ice Sheet (LIS), was ice-free for parts of Marine Isotope Stage 3 (MIS 3; 57,000 to 29,000 yr BP), MIS 5 (130,000 to 71,000 yr BP) and MIS 7 (243,000 to 190,000 yr BP). The MIS 3 age assignment is notable since it suggests the possibility of significant retreat of the LIS and a relatively high global sea level, both of which are a contrast to assumptions that North America was moderately glaciated, and that global sea level was relatively low during that time interval. Paleoecological proxies, including pollen and plant macrofossils, suggest that the HBL contained peatland and boreal vegetation during all previous non-glacial intervals, and pollen-based quantitative reconstructions of sites which are hypothesized to be MIS 3 and MIS 5a (~80,000 yr BP) in age suggest that climate during MIS 3 may have had less annual precipitation than during MIS 5a and present day. Stratigraphic analyses of these glacial and non-glacial sediments provide insight into the dynamicity of Late Pleistocene ice sheets; multiproxy analyses of three stratigraphic successions along the Albany River resulted in the recognition of at least three glacial advances from shifting ice centers within the QuĂŠbec sector of the Laurentide Ice Sheet during the Late Pleistocene. This dissertation contributes a chronological dataset for reconstructing the movement, timing and dynamics of Late Pleistocene ice sheets over North America, as well as paleoecological data for understanding the character and distribution of boreal peatlands during previous interstadial and interglacial periods. Ph.D. |
author2 |
Finkelstein, Sarah A Earth Sciences |
format |
Thesis |
author |
Dalton, April Sue |
author_facet |
Dalton, April Sue |
author_sort |
Dalton, April Sue |
title |
Chronology, Paleoecology and Stratigraphy of Late Pleistocene Sediments from the Hudson Bay Lowlands, Canada |
title_short |
Chronology, Paleoecology and Stratigraphy of Late Pleistocene Sediments from the Hudson Bay Lowlands, Canada |
title_full |
Chronology, Paleoecology and Stratigraphy of Late Pleistocene Sediments from the Hudson Bay Lowlands, Canada |
title_fullStr |
Chronology, Paleoecology and Stratigraphy of Late Pleistocene Sediments from the Hudson Bay Lowlands, Canada |
title_full_unstemmed |
Chronology, Paleoecology and Stratigraphy of Late Pleistocene Sediments from the Hudson Bay Lowlands, Canada |
title_sort |
chronology, paleoecology and stratigraphy of late pleistocene sediments from the hudson bay lowlands, canada |
publishDate |
2017 |
url |
http://hdl.handle.net/1807/80863 |
long_lat |
ENVELOPE(-81.517,-81.517,52.283,52.283) |
geographic |
Albany River Canada Hudson Hudson Bay |
geographic_facet |
Albany River Canada Hudson Hudson Bay |
genre |
Albany River Hudson Bay Ice Sheet |
genre_facet |
Albany River Hudson Bay Ice Sheet |
op_relation |
http://hdl.handle.net/1807/80863 |
_version_ |
1766226023056146432 |