Extent and thickness of the Labrador ice-sheet

Ice Marks in Newfoundland: A History of Ideas

“…If the lllinoian was also missing in eastern Canada and Newfoundland, the long ice-free period he sought was readily available. COLEMAN (1926) found further support for two glaciations in Newfoundland by giving interglacial status to marine clay with shells found between glacial deposits at Curling, near Corner Brook (p. 213). Similar marine clays, containing unfossilized shells of many species which inhabit eastern Canadian waters today, had been commonly known since the mid-19th century in the valley and Gulf of St. Lawrence regions, and had early been assigned by Logan (GEOLOGICAL SURVEY OF CANADA, 1863) to the period following the formation of the glacial deposits.…”

“…Up to this time there had been no debate over the age of the glaciation, over whether more than one episode of glaciation was in evidence, or over the details of the extent and thickness of ice over Newfoundland. COLEMAN (1920COLEMAN ( , 1921COLEMAN ( , 1922 found no evidence that these highlands had ever been overswept by the Labrador ice sheet. This view was congruent with that held by CHALMERS (1895), that lowland glaciers had been of restricted extent around the western Gulf of St. Lawrence.…”

“…In the summers of 1924 and 1925 (at age 72-73), Coleman turned his attention to Newfoundland (COLEMAN, 1926). He was impressed by the same weathered character of plateaus and hilltops standing above areas which showed, in their striated bedrock surfaces and fresh glacial deposits, that they had been recently glaciated.…”

“…Over the higher areas, including summits at about 300 m in the Avalon Peninsula and plateaus over 600 m high in the Long Range Mountains, glacial boulders were recorded perched on weathered bedrock eminences, or seated within blocky mantles of weathered rock. In the southern Long Range Mountains, above the Codroy River lowland, COLEMAN (1926) could find no evidence of glaciation at all: "No foreign bowlders [sic] were found, and the conclusion was reached that the southern part of the Long Range had never been glaciated" (p. 209).…”

“…On the question of the source of the two glaciations of Newfoundland, COLEMAN (1926) proposed that the earlier one, of "Kansan or Jerseyan age", "covered all of the island except the southern part of the Long Range,... It is probable that the Newfoundland ice was really the margin of the Labrador sheet which more or less completely filled the Gulf of St. Lawrence and expanded over all but the highest tableland of the southern part of the island.…”