CGRG Bibliography of Canadian Geomorphology
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Author : Burge, L.M.
Date : 1997
Title : Meandering river eddy accretions: sedimentology, morphology, architectural geometry, and depositional processes
Publication : Unpublished M.Sc. thesis. University of Calgary, Calgary
Issue :
Page(s) : 99 p.
Abstract
Very little is known about the sedimentology of eddy accretions (elsewhere termed concave bench deposits). These deposits occur where parallel bedrock valley walls confine a channel meander belt, preventing formation of oxbow cutoffs. In such confined settings, eddy accretions form along both margins of the floodplain, where deep scour holes are eroded by bankfull river flows impacting valley sides at right angles. In unconfined meanders, eddy accretions form where meander belt channels impinge upon valley walls. Commonly in confined settings, each eddy accretion deposit occupies 25 percent of the floodplain surface and the lower portion of a second eddy accretion deposit underlies the point bar. Typically, confined meanders with eddy accretions have a ratio of floodplain width to channel width of between 6:1 and 9:1. Eddy accretions are previously unrecognized as potentially thick aquifers and major fairways for fluid movement in incised river valley-fills associated with marine transgressions following a sealevel low stand. In deeply-buried ancient rock sequences, valley margins with thick eddy accretion sandstones should be considered as preferred exploration targets by the oil and gas industry.
Bibliography of Canadian Geomorphology