Late glacial ice margins and deglacial chronology for southeastern Baffin Island and Hudson Strait, eastern Canadian Arctic

1992 ◽  
Vol 29 (5) ◽  
pp. 1000-1017 ◽  
Author(s):  
Jay A. Stravers ◽  
Gifford H. Miller ◽  
Darrell S. Kaufman
Keyword(s):  
Canadian Arctic ◽  
Late Glacial ◽  
Hudson Bay ◽  
Baffin Island ◽  
Radiocarbon Dates ◽  
Glacial Ice ◽  
Sea Levels ◽  
Molluscan Fauna ◽  
Rising Sea Levels ◽  
Eastern Canadian Arctic

Radiocarbon dates from marine piston cores and from onshore raised marine stratigraphic sections in the Hudson Strait region were used to reconstruct deglacial isochrons for 9900, 9500, 8800–8500, and 8000 BP. At the culmination of the Gold Cove readvance (9900 BP), Labrador–Ungava ice flowed northeastward across Hudson Strait and outer Frobisher Bay and stood for the last time on the Baffin Island continental shelf. Subsequent retreat by calving was rapid and profound, opening the entire Hudson Strait marine trough by 9500 BP. At this time, ice dispersal from Foxe Basin, Labrador–Ungava, and local ice on Meta Incognita Peninsula supported tidewater margins along much of the coastline, with the exception of northernmost Ungava Peninsula, where the ice margin stabilized onshore. This onshore margin remained in place throughout the Cockburn Substage while a major northeastward readvance of Ungava Bay ice (the Noble Inlet readvance from 8800 to 8500 BP) crossed outer Hudson Strait, grounding on the Hudson Strait sill and the south coast of Meta Incognita Peninsula. Sedimentation continued in an enclosed basin in western Hudson Strait, but marine circulation was prohibited by the ice dam, and upper water column salinities became too low to support a marine molluscan fauna. Ungava Bay ice was not thick enough to sustain flow across eastern Hudson Strait, and rising sea levels soon destroyed the Noble Inlet ice dam. By 8300 BP normal marine waters were circulating in eastern Hudson Strait, followed shortly thereafter (at 8100 BP) by the deglaciation of western Hudson Strait and Hudson Bay.

Late glacial ice margins and deglacial chronology for southeastern Baffin Island and Hudson Strait, eastern Canadian Arctic: Reply

1993 ◽  
Vol 30 (8) ◽  
pp. 1753-1758 ◽  
Author(s):  
Darrell S. Kaufman ◽  
Gifford H. Miller ◽  
Jay A. Stravers ◽  
William F. Manley ◽  
Mathieu L. Duvall
Keyword(s):  
Canadian Arctic ◽  
Late Glacial ◽  
Baffin Island ◽  
Glacial Ice ◽  
Eastern Canadian Arctic

Two Assemblages of Marine Algae from Post-Glacial Deposits in the Eastern Canadian Arctic

1972 ◽  
Vol 9 (1) ◽  
pp. 109-115 ◽  
Author(s):  
W. I. Illman ◽  
J. McLachlan ◽  
T. Edelstein
Keyword(s):  
Marine Algae ◽  
Canadian Arctic ◽  
Species Assemblages ◽  
Hudson Bay ◽  
Baffin Island ◽  
Glacial Deposits ◽  
Eastern Canadian Arctic

The marine algae of the post-glacial deposits from the Ottawa Islands, Hudson Bay and Broughton Island off East Baffin Island were examined. A total of 15 non-calcareous species were identified, of which the most abundant at both sites were Sphacelaria plumosa and Desmarestia aculeata. The species assemblages are characteristic of present-day arctic and subarctic floras.

Postglacial emergence of Ungava Peninsula, and its relationship to glacial history

1993 ◽  
Vol 30 (8) ◽  
pp. 1676-1696 ◽  
Author(s):  
James Gray ◽  
Bernard Lauriol ◽  
Denis Bruneau ◽  
Jean Ricard
Keyword(s):  
Tide Gauge ◽  
High Tide ◽  
Ice Sheet ◽  
Late Glacial ◽  
Hudson Bay ◽  
Radiocarbon Dates ◽  
Glacial Ice ◽  
Marine Terraces ◽  
New Synthesis ◽  
Rapid Deceleration

A series of 178 radiocarbon dates, of late glacial and postglacial age, from raised marine terraces on the Hudson Strait, Hudson Bay, and Ungava Bay coasts, permit a new synthesis of deglaciation history, postglacial emergence, and glacio-isostatic recovery of the Ungava Peninsula. Marine limits show three local highs, related to centres of ice loading: east of Hudson Bay; southwest of Ungava Bay, and in western Hudson Strait. Eastward extension of the latter to Cap de Nouvelle-France is attributed to early deglaciation. Emergence curves are presented from sites in (1) Hudson Strait ice-free prior to 9 ka; (2) Hudson Strait; (3) Hudson Bay; and (4) Ungava Bay liberated by Ungava ice between 8 and 6 ka. A sigmoidal pattern for the first group, with slow initial emergence, contrasts markedly with a pattern of rapid deceleration of emergence for the other groups. These differences are attributed to variations in rates of ice sheet unloading, immediately after coastal deglaciation. A stable onshore ice margin kept the northeastern tip of Ungava isostatically depressed, from initial deglaciation until 7 ka, whereas other mainland coasts were only liberated by retreat of the ice margin during a final phase of rapid thinning of the continental ice sheet. Isobases on emergence since 6.5, 5, and 2 ka, derived from marine and glacial lake shoreline data, indicate maximum ice loading centres in eastern Hudson Bay and in central Quebec–Labrador, with an extension northwards towards Ungava Bay. An uplift rate of 14 mm/year since 2 ka for Inukjuak on the Hudson Bay coast is compatible with very high tide gauge values. A downward gradient of 6.5 ka isobases in a northeasterly direction from southeastern Ungava towards present sea level on southern Resolution Island at the mouth of Hudson Strait suggests that Ungava Bay, despite late occupation by glacial ice, was probably not a major loading centre.

Wisconsin Glacial Chronology and Relative Sea-level Movements, Narpaing Fiord Broughton Island Area, Eastern Baffin Island, N.W.T.

1973 ◽  
Vol 10 (11) ◽  
pp. 1621-1641 ◽  
Author(s):  
D. R. Pheasant ◽  
J. T. Andrews
Keyword(s):  
Sea Level ◽  
Positive Relationship ◽  
Canadian Arctic ◽  
Baffin Island ◽  
Sea Levels ◽  
Ice Load ◽  
Isostatic Equilibrium ◽  
Glacial Chronology ◽  
Continental Glaciation ◽  
Eastern Canadian Arctic

Three distinct glacier advances and four major periods of adjustment of relative land and sea levels are recognized in the Wisconsin age stratigraphic and geomorphologic record of the Northern Cumber-land Peninsula. The coast, which is presently undergoing submergence, is close to an isostatic equilibrium position following rapid land emergence during post-Cockburn time (ca. 8000–1000 BP). Laurentide ice advances during two earlier stades—the Alikdjuak ca. 115 000 BP and the Napiat > 40 000 BP—were more extensive than the Cockburn glacier advances and a positive relationship between ice load and amount of crustal deflection at the ice margin is demonstrated. Computations based on synchronous raised marine features and known extent of the ice load indicate a crustal flexural parameter (α) of > 80 km and perhaps > 135 km for this area. The date of the Alikdjuak stade suggests the time transgressive nature of the early-Wisconsin maximum position of the continental ice sheet margin and supports the hypothesis that continental glaciation may well have originated in the climatically sensitive uplands of the eastern Canadian arctic/sub-arctic.

Late glacial and post-glacial history and emergence of the Ottawa Islands, Hudson Bay, Northwest Territories: Evidence on the deglaciation of Hudson Bay

1969 ◽  
Vol 6 (5) ◽  
pp. 1263-1276 ◽  
Author(s):  
J. T. Andrews ◽  
G. Falconer
Keyword(s):  
Northwest Territories ◽  
Sea Level ◽  
Late Glacial ◽  
Hudson Bay ◽  
Baffin Island ◽  
Glacial History ◽  
The West ◽  
Radiocarbon Dates ◽  
Northeastern Part ◽  
Present Rate

The Ottawa Islands are in the northeastern part of Hudson Bay. Evidence from crossing striations suggests that the earliest recorded glacial movement was toward the northeast. With deglaciation of Hudson Strait and central Hudson Bay the ice movement shifted progressively in an anti-clockwise direction, with the final movement being toward the west–southwest. The islands were deglaciated between 7610 and 7250 radiocarbon years ago. The marine limit is 158 m above sea level. Deltaic deposits below the marine limit are grouped into sets that correlate with glacial advances in Labrador–Ungava and Baffin Island, and with palynological results from Keewatin, suggesting that they reflect climatically induced processes rather than a balance in eustatic–isostatic movements. Radiocarbon dates on marine molluscs enable postglacial uplift and emergence curves to be drawn, which agree closely with predicted curves. Rates of uplift were about 0.06 m yr−1 at 6500 yr B.P., whereas the present rate is about 0.008 m yr−1. The deglaciation of Hudson Bay was marked by the splitting of the ice sheet along the submarine deep that trends southward between Mansel and Coats islands toward the southwest coast of the bay.

Conodont paleontology and biostratigraphy of Ordovician carbonates and petroliferous carbonates on Southampton, Baffin, and Akpatok islands in the eastern Canadian Arctic

1989 ◽  
Vol 26 (10) ◽  
pp. 1880-1903 ◽  
Author(s):  
Alexander D. McCracken ◽  
Godfrey S. Nowlan
Keyword(s):  
Canadian Arctic ◽  
Bedding Plane ◽  
Baffin Island ◽  
Jordan River ◽  
Oil Shales ◽  
Age Range ◽  
Eastern Canadian Arctic

Carbonate and petroliferous carbonate units ("oil shales") on Southampton, Baffin, and Akpatok islands have yielded a total of 2277 conodonts, the more biostratigraphically useful of which indicate not all units are correlative. The Boas River "shale", the lower of the two petroliferous units on Southampton Island, overlies the Bad Cache Rapids Group and contains a diverse fauna, including elements of Amorphognathus ordovicicus Branson and Mehl. Previous reports have indicated the presence of Culumbodina penna Sweet, a species whose range only barely overlaps that of A. ordovicicus in the middle Maysvillian. Carbonate beds and bedding-plane surfaces of the higher Red Head Rapids Formation at Sixteen Mile Brook yielded A. ordovicicus faunas containing Aphelognathus cf. A. divergens Sweet. These beds are likely Richmondian, since A. divergens is known elsewhere only from Richmondian strata. A metasicula of "Glyptograptus" hudsoni Jackson, several natural conodont assemblages, and fused enigmatic coniform elements were also found at Sixteen Mile Brook.The petroliferous unit in unnamed strata at Amadjuak Lake on Baffin Island contains Belodina area Sweet, which is indicative of a late Edenian to early Maysvillian age. Conodonts from the petroliferous strata at Jordan River on Baffin Island suggest a Trentonian to early Maysvillian age. The conodonts recovered from unnamed strata on Akpatok Island are not very diagnostic but indicate an age range from Shermanian to Gamachian.

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