CGRG Bibliography of Canadian Geomorphology
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Author : Bornhold, B.D.; and Prior, D.B.
Date : 1990
Title : Morphology and sedinmentary processes on the subacqueous Noeick River delta, British Columbia, Canada
Publication : Coarse-Grained Deltas. Edited by: A. Colella; and D.B. Prior. Special Publication of the International Association of Sedimentologists. Blackwell. Oxford, International
Issue : 10:
Page(s) : 169-181
Abstract
The Noeick River has deposited a large fan delta along the sidewall of South Bentinck Arm, a fjord on the central British Columbia coast. The intertidal and supratidal delta has an area of about 8 x 10(5) m(2), the underwater delta-front gradient averages 4-5o to water depths of 220 mm about 2 km from shore. The Noeick River drains a high-relief basin of which 15% is covered by glaciers . In addition to large, annual floods related to snow- and icemelt, the river has experienced jokulhaups, glacier outburst floods, the most recent of which were in October 1984 and August 1986. The floods caused major changes in the subaerial delta, including relocation of distributaries and the delivery of large quantitites of coarse sediment, trees and other organic debris to the delta and adjacent inlet. Side-scan sonar imagery and seismic profiling on the subacqueous delta revealed a suite of morphological features and sedimet distribution patterns indicative of high-energy sediment-transport processes and little evidence of in-situ failure. Seaward of the main subaerial distributary channel, radiating chutes and swales containing sand and gravel lead towards deeper water. Between 120 m and 170 m water depth, flutes, commonly aligned downslope, dominate the subacqueous delta. Further downslope, there is an extensive area of traverse synmmetrical bedforms, 2-5 m high with wavelengths of 50-120 m, interpreted as anitdunes. Sediments on the subacqueous delta front consist of interstratifed organic-rich sandy muds and gravelly sands.
Bibliography of Canadian Geomorphology