scholarly journals Amino Acid Evidence Indicating Two or More Ages of Pre-Holocene Nonglacial Deposits In Hudson Bay Lowland, Northern Ontario

2007 ◽  
Vol 44 (3) ◽  
pp. 389-393 ◽  
Author(s):  
Philip H. Wyatt
Keyword(s):  
Amino Acid ◽  
Marine Sediments ◽  
Organic Material ◽  
Hudson Bay ◽  
Last Interglacial ◽  
Northern Ontario ◽  
Glacial Sediments ◽  
Hudson Bay Lowland

ABSTRACT Amino acid studies have identified pre-Holocene non-glacial sediments in the Hudson Lowland which are significantly younger than Bell Sea sediments of the Missinaibi Formation. This younger unit is represented by marine sediments on the Severn and Abitibi rivers. Buried organic material on Beaver River is correlated with the younger Severn and Abitibi river marine sediments based on amino acid evidence. Assuming that Bell Sea sediments are of last interglacial (130-120 ka) age, the younger nonglacial sediments may have been deposited late in 18O stage 5 (80-75 ka). Paleoecologic studies of the Beaver River organics indicate climate at least as warm as present.

The last interglacial–glacial cycle, Clyde foreland, Baffin Island, N.W.T.: stratigraphy, biostratigraphy, and chronology

1977 ◽  
Vol 14 (12) ◽  
pp. 2824-2857 ◽  
Author(s):  
G. H. Miller ◽  
J. T. Andrews ◽  
S. K. Short
Keyword(s):  
Amino Acid ◽  
Marine Sediments ◽  
Baffin Island ◽  
Buried Soils ◽  
Last Interglacial ◽  
Pollen Assemblage ◽  
Outlet Glacier ◽  
Radiocarbon Dates ◽  
Last Glaciation

A study of the stratigraphic sequence (14C and amino acid age control), marine bivalve faunal changes, and palynology of buried soils and organic-rich sediment collected from the Clyde Foreland Formation in the extensive cliff sections of the Clyde foreland, eastern Baffin Island, N.W.T., suggests the following last interglacial – Foxe (last glaciation) glacial – present interglacial sequence.(1) Cape Christian Member (ca. 130 000 years BP?)Consists of the Sledgepointer till overlain by the Cape Christian marine sediments. In situ molluscan fauna, collected from the marine sediments, contain a moderately warm bivalve assemblage. A well-developed soil that formed on the marine sediments (Cape Christian soil) contains an interglacial pollen assemblage dominated by dwarf birch. U-series dates of > 115 000 and ca. 130 000 years BP on molluscs from the Cape Christian marine sediments suggest that they were deposited during the last interglaciation, here termed the Cape Christian Interglaciation. The development of a subarctic pollen assemblage in the Cape Christian soil has not been duplicated during the present interglaciation, suggesting higher summer temperatures and perhaps a duration well in excess of 10 000 years for the last interglaciation.(2) Kuvinilk MemberConsists of fossiliferous marine sediments, locally divided by the Clyde till into upper and lower units. The Clyde till was deposited by the earliest and most extensive advance of the Foxe (last) Glaciation. Kuvinilk marine sediments both under- and overlying the Clyde till contain the pecten Chlamys islandicus, indicating that the outlet glacier advanced into a subarctic marine environment. Amino acid ratios from in situ pelecypod shells abovę and below the Clyde till are not statistically different, but contrast markedly with ratios obtained from the same species in the Cape Christian Member. Organic horizons within the Kuvinilk marine sediments contain a relatively rich pollen assemblage, although 'absolute' counts are low.(3) Kogalu Member (> 35 00014C years BP)Sediments of the Kogalu Member unconformably overlie those of the Kuvinilk Member, but are of a similar character. The dominant sediments are marine in origin, but in places are divided into upper and lower units by the Ayr Lake till. Amino acid ratios from in situ shells above and below the Ayr Lake till are indistinguishable, but substantially less than those in the Kuvinilk Member, suggesting the two members are separated by a considerable time interval. Radiocarbon dates on shells in the Kogalu marine sediments range from 33 000 to 47 700 years BP, but these may be only minimum estimates. The sea transgressed to a maximum level 70–80 m asl, coincident with the glacial maximum. Subarctic marine fauna of interstadial–interglacial character occur within the Kogalu marine sediments.(4) Eglinton Member (10 000 years BP to present)A major unconformity exists between the Kogalu and Eglinton Members. Ravenscraig marine sediments were deposited during an early Holocene marine transgression–regression cycle; the oldest dates on these sediments are ca. 10 000 years BP. Locally a vegetation mat occurs at the base or within the Ravenscraig unit. Pollen from these beds is sparse, but indicates a terrestrial vegetation assemblage as diverse as that of today. There is no evidence that Laurentide Ice reached the foreland during the last 30 000 years. Eolian sands that overlie a soil developed on the marine sediments record a late Holocene climatic deterioration. Pollen in organic-rich sediments at the base of, and within, the eolian sands record a vegetation shift in response to climatic change.

Succession in the Hudson Bay Lowland, Northern Ontario, Canada

1996 ◽  
Vol 28 (2) ◽  
pp. 172 ◽  
Author(s):  
Lee F. Klinger ◽  
Susan K. Short
Keyword(s):  
Hudson Bay ◽  
Northern Ontario ◽  
Hudson Bay Lowland

scholarly journals Additions to the Vascular Flora of Ontario, Canada, from the Sutton Ridges, Hudson Bay Lowland Ecoregion

2011 ◽  
Vol 125 (3) ◽  
pp. 241 ◽  
Author(s):  
Michael J. Oldham ◽  
Samuel R. Brinker
Keyword(s):  
North America ◽  
Plant Species ◽  
Vascular Plant ◽  
Field Studies ◽  
Hudson Bay ◽  
Northern Ontario ◽  
Vascular Flora ◽  
Arctic Plants ◽  
Diapensia Lapponica ◽  
Hudson Bay Lowland

Field studies in the Hudson Bay Lowland ecoregion of northern Ontario during 2010 resulted in the discovery of four native vascular plant species not previously confirmed from the province: Arctic Bellflower (Campanula uniflora; Campanulaceae), Lapland Diapensia (Diapensia lapponica; Diapensiaceae), Alpine Azalea (Kalmia procumbens; Ericaceae), and Alpine Brook Saxifrage (Saxifraga rivularis; Saxifragaceae). These four species are widespread arctic plants occurring in both North America and Eurasia and were found on the Sutton Ridges, a Precambrian bedrock inlier surrounded by the extensive wetlands of the Hudson Bay Lowland.

Thermoluminescence properties and age estimates for Quaternary raised marine sediments, Hudson Bay Lowland, Canada

1987 ◽  
Vol 24 (12) ◽  
pp. 2405-2411 ◽  
Author(s):  
S. L. Forman ◽  
A. G. Wintle ◽  
L. H. Thorleifson ◽  
P. H. Wyatt
Keyword(s):  
Marine Sediments ◽  
Linear Growth ◽  
Control Sample ◽  
Growth Curves ◽  
High Light ◽  
Hudson Bay ◽  
Radiocarbon Age ◽  
Hudson Bay Lowland ◽  
Initial Results ◽  
Age Estimates

Thermoluminescence (TL) analyses of Quaternary nearshore marine sediments from the Hudson Bay Lowland revealed relatively high light emissions and linear growth curves to at least 400 Gy above the natural dose. Initial results indicate that anomalous fading may be circumvented by a preheating at 150 °C for 16 h without substantial thermal draining of stable TL components. Both the total bleach method with unfiltered sunlamp light and the partial bleach method with light blocked below 400 nm resulted in overbleaching and thus overestimates of age. A TL age estimate of 5.3 ± 0.8 ka on the Holocene control sample, similar to the radiocarbon age, was obtained using the partial bleach method with light blocked below 540 nm. This same method yielded an average TL age estimate of 73 ± 10 ka for a Pleistocene unit, which corresponds to the amino-acid-based age estimate of ca. 76 ka. The agreement of the two age estimates is encouraging, since both methods rely on separate assumptions that have not been independently verified.

scholarly journals Paleoecology of Organic Deposits of Probable Last Interglacial Age in Northern Ontario

2007 ◽  
Vol 44 (3) ◽  
pp. 309-318 ◽  
Author(s):  
Robert J. Mott ◽  
Ronald N. W. DiLabio
Keyword(s):  
Deep Sea ◽  
Hudson Bay ◽  
Last Interglacial ◽  
Northern Ontario ◽  
Hudson Bay Lowlands ◽  
Organic Sediment ◽  
Oxygen Isotope Record ◽  
Isotope Record ◽  
Organic Deposits ◽  
River Valleys

ABSTRACT Nonglacial deposits in northern Ontario that may date to the last interglacial interval are well known from the Hudson Bay Lowlands where they have been described in sections along several river valleys. Soil horizons, peat beds and other organic sediment sequences comprise the Missinaibi Formation of the Moose River Basin studied for pollen and macrofossils. Results suggest that the climate was as warm or warmer than present, and spruce woodlands prevailed among broad expanses of bog and fen. The Beaver River peat records conditions similar to the present in the Fort Severn area with open spruce woodlands dispersed in peatlands. South of the Lowlands in the Timmins area, a widespread organic-silt horizon termed the Owl Creek beds is stratigraphically equivalent to the Missinaibi Formation. The waning phase of a warm interval is represented, with early climate possibly similar to the present and the later climate much cooler. Correlation of the Missinaibi Formation with substage 5e of the deep-sea oxygen isotope record is corroborated by amino acid results on marine shells from some associated units. Analysis of shells from beneath the Beaver River peat bed indicate that this interval may be considerably younger, possibly substage 5c or, more likely, 5a. The Owl Creek beds may relate to sub-stage 5e, or to one of the younger intervals, 5c or 5a.

MACROFOSSIL AND BIOMARKER RECORD FROM HUDSON BAY LOWLAND SOUTH RIDGE HOLLOW BOG, NORTHEAST ONTARIO

2016 ◽  
Author(s):  
Rebecca Snyder ◽  
◽  
Dorothy Peteet ◽  
Jonathan Nichols ◽  
Sarah Finkelstein ◽  
...  
Keyword(s):  
Hudson Bay ◽  
Hudson Bay Lowland

Constraining the age of the last interglacial–glacial transition in the Hudson Bay lowlands (Canada) using U–Th dating of buried wood

2012 ◽  
Vol 7 ◽  
pp. 37-47 ◽  
Author(s):  
G. Allard ◽  
M. Roy ◽  
B. Ghaleb ◽  
P.J.H. Richard ◽  
A.C. Larouche ◽  
...  
Keyword(s):  
Hudson Bay ◽  
Last Interglacial ◽  
Hudson Bay Lowlands
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