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Coarse cliff‐top aeolian sedimentation in northern Gaspésie, Québec (Canada)
Author(s) -
Hétu Bernard
Publication year - 1992
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.3290170108
Subject(s) - aeolian processes , geology , cliff , debris , geomorphology , physical geography , snow , plateau (mathematics) , landslide , sedimentation , hydrology (agriculture) , oceanography , sediment , paleontology , geotechnical engineering , geography , mathematical analysis , mathematics
This paper deals with the effects of wind on rockwall dynamics. On 5 and 6 January, 1988 very strong northwest winds (blizzard) were blowing onto the rockwall of Mount Saint‐Pierre (alt.: 424 m), Gaspésie, Québec (Canada). The most violent recorded squall reached 99·4 km h −1 . During this event, the summit plateau received a large amount of aeolian sediments originating from the shale rockwall that forms the mountain's northwest side. In the 15 to 20 m wide by 75 m long belt located along the top of the rockwall, over a 1200 m 2 area, a continuous layer of debris completely covered the snow. This layer of debris had a mean thickness of 11·4 mm, which represents an accumulated volume in the order of 13 m 3 . Largely dominated by sand and granules (2–4 mm), the 28 samples collected for grain‐size analysis also contained numerous thin shale flakes, many of which were longer than 10 mm. The largest flake measured had a width of 134 mm and a weight of 164·3 g. Six available 14 C dates provide information concerning mean cliff‐top aeolian sedimentation rate for the last thousand years ( c . 1·8 mmyr −1 ).