ABSTRACT: Periglacial features and landscape evolution, central Bathurst Island, District of Franklin

CGRG Bibliography of Canadian Geomorphology
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Abstract

While carrylng out a reconnaissance of the surficial geology of Bathurst Island in 1963, a number of observations were made of periglacial features, especially those which occur along the low, central valley which crosses the island. Much of the 1963 field season, as well as June 1964, was devoted to collecting samples of terrestrial and marine materials for radiocarbon dating, in order to establish a chronology of events bearing on the glacial history of the island (Blake, 1964, 1974). Close to 8500 years ago the sea filled Polar Bear Pass, which now does not exceed 100 feet (30 m) in elevation, to a depth of more than 150 feet (46 m). As the land rose relative to the sea, because of isostatic rebound following removal of the ice load, features such as the beach ridges shown in Figures 4 and 5, were cut at successively lower elevations; the particular ones illustrated, above the 200 foot (60 m) level, are close to 8000 years old. On the other hand, the uppermost layer of Mya truncata shells exposed in a section along the Caledonian River at the western end of Polar Bear Pass is 4750 ą 140 years old (GSC-783; Blake, 1970; Lowden et al., 1971), and sea level at the time these molluscs were living was an unknown amount above the level at which they now occur, ca. 75 feet (23 m). This is approximately the same elevation as that of the largest lake now occupylng Polar Bear Pass (Figure 1), indicating that this through valley persisted as an arm of the sea until nearly 4500 years ago. (Excerpts)

Bibliography of Canadian Geomorphology