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1993. M.Sc., 229 pp.
FOURIER SHAPE ANALYSIS OF COASTAL SANDS FROM THE
HIGH ARCTIC TO COLD TEMPERATE REGIONS OF CANADA
MACKAY, W.
 The shape and surface textures of quartz grains from
the fine sand fraction of coastal sediments from arctic (Foxe Basin), subarctic
(Hudson Bay and James Bay) and cold temperate (Wasaga Beach) settings were
analyzed using Fourier shape analysis and scanning electron microscopy.
Although, significant differences were found between the arctic samples and the
others, the differences were related to source of material rather than modern
climate -dependent processes. The shape frequency distributions of most samples
from Foxe Basin were preferentially influenced by the presence of aeolian well
rounded and spherical aeolian grains, presumably derived from reworked
Pleistocene sands. Other samples exhibit very distinct shape frequency
distributions associated with very angular grains derived from the weathering of
local igneous and metamorphic bedrock coastal cliffs. Little variation has been
found in samples from Hudson Bay and James Bay, in part because the sampling was
biased toward intertidal environments. A differential shape sorting transport
process has been instead detected consistently in Wasaga Beach. Differential
shape sorting, whereby more rounded and spherical grains preferentially move to
coastal dunes from beaches, is preferred over modification of grains by
abrasion, because of the short (few kilometers) distance of transport from
beaches to dunes.
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