Holocene gelifluction in a snow-patch environment at the Forest-Tundra Transition along the eastern Hudson Bay Coast, Canada

The Holocene chronology of gelifluction events in a snow-patch environment of the Richmond Gulf area, eastern Hudson Bay Coast (northern Québec), has been constructed using sixty radiocarbon-dated buried organic horizons. The samples were recovered from nine soil trenches located along an altitudinal gradient associated with a chronosequence as determined by the regional land emersion curve. The most significant gelifluction activity occurred after c. 2,800 B. P. Gelifluction events occurred around 5,600, 5,000, 4,500, 3,150, 2,500, 1,550, 1,200 and 450 B.P., and at present. According to the frequency of ¹⁴C dates. gelifluction has been particularly active between 2,800-2,300, 1,700–900 and 600-300 B.P., and at present. Gelifluction occurrence seems to be closely related to well-bracketed cold episodes in northern Québec. The increase in frequency of ¹⁴C dates associated with burial of organic matter through gelifluction after c. 2,800 B. P. substantiates the colling trend depicted elsewhere, both in northern Québec and in the northern hemisphere.