CGRG Bibliography of Canadian Geomorphology
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Author : Duvall, M.L.
Date : 1993
Title : Late Foxe glacial geology of the mid-bay area of Frobisher Bay, southeast Baffin Island, Northwest Territories
Publication : Unpublished M.Sc. thesis. University of Colorado, Boulder
Issue :
Page(s) : 103 p
Abstract
Field mapping ice flow indicators, surficial sediments, Paleozoic limestone erratics, and carbonate-rich drift help define the northern limits of Labrador ice in the mid Frobisher Bay area. A drift sheet, ice flow indicators, and the coverage of limestone erratics define a maximum limit of the ice that extends from Gabriel and McLean islands in the west to southern Hamlen Bay Peninsula and Barrow Peninsula in the east. The spatial coverage of carbonate-rich drift delimits a minimum extent of Labrador ice that extends from Beauty Bay in the east to Gabriel and McLean islands in the west. Labrador ice did not interact with Foxe/Amadjuak ice in the mid-bay area. A small amount of evidence suggests that a proglacial lake existed between Foxe/Amadjuak ice and Labrador ice. Labrador ice did interact with ice from Hudson Strait that overtopped Meta Incognita Peninsula. This ice interaction produced the northeast and east ice-flow directions observed in the mid-bay area. Percent carbonate, magnetic susceptibility (MS) and particle size analysis on 51 drift samples from the mid and outer Frobisher Bay area indicate that carbonate is the best discriminator between drift from Labrador ice and drift from other ice masses. The spatial distribution of high MS and carbonate-rich drift in the mid and outer bay arc due to deposition from Labrador ice. The MS signal is variable because of the heterogeneous occurrence of the high MS material in the Precambrian source-rock. A 10 m segment from marine core HU90-023-001 provides a 2700 yr. (8.4-5.7 ka BP) sedimentary record from the trough of Frobisher Bay. Percent carbonate, MS,. particle size, and foraminifera data define two clay-rich, high carbonate, and low MS layers dominated by the foraminifera Elphidium excavatum forma clavatum. These layers correlate with the Hall Clay (Osterman 1982) and record relatively cold, fresh and turbid water conditions associated with the focusing of sediment from the Noble Inlet advance into the trough of the bay. Between 7.0 and 8.3 ka BP ice distal sedimentation occurred at the core site because of ice at the head of Frobisher Bay. An advance of local ice (from Meta Incognita Peninsula ?) between 7.1 and 7.3 ha BP, is superimposed on these baseline conditions.
Bibliography of Canadian Geomorphology