Submarine Sedimentation on a Developing Holocene Fan Delta

  1. Dorrik A. V. Stow
  1. David B. Prior1 and
  2. Brian D. Bornhold2

Published Online: 29 APR 2009

DOI: 10.1002/9781444304473.ch33

Deep-Water Turbidite Systems

Deep-Water Turbidite Systems

How to Cite

Prior, D. B. and Bornhold, B. D. (2009) Submarine Sedimentation on a Developing Holocene Fan Delta, in Deep-Water Turbidite Systems (ed D. A. V. Stow), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304473.ch33

Editor Information

  1. Department of Geology, University of Southampton, UK

Author Information

  1. 1

    Geological Survey of Canada, Atlantic Geoscience Centre, Dartmouth, Nova Scotia, Canada B2Y 4A2

  2. 2

    Geological Survey of Canada, Pacific Geoscience Centre, Sidney, British Columbia, Canada V8L 4B2

Publication History

  1. Published Online: 29 APR 2009
  2. Published Print: 11 NOV 1991

ISBN Information

Print ISBN: 9780632032624

Online ISBN: 9781444304473

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Keywords:

  • fault-controlled small-basin fans;
  • Fjors-dide fan-delta;
  • Pleistocene/early Holocene glaciomarine sediments;
  • three-dimensional geometry of Bear Bay;
  • Bute Inlet, one of the deepest fjords in British Columbia

Summary

The submarine morphology, sediments, and three-dimensional geometry of a developing fan delta are described using data from acoustic surveys, bottom sampling, and observations from a manned submersible. The fan system is being built in a British Columbian fjord (water depth 410 m) supplied with coarse-grained sediments from a fjord-side river.

Construction of the subaqueous fan began about 10–12,000 yr BP and is ongoing. The system is analogous to part of one fault-uplift sedimentation cycle in ancient fan deltas. Initially, when offshore relief was at a maximum, acoustically chaotic sediment wedges were emplaced over fjord-bottom glaciomarine deposits. Subsequent aggradation/progradation resulted in moderately dipping sequences interrupted by local chaotic units. The present fan surface (average slope 13°) is divided into six zones arranged concentrically from the fan apex, on the basis of form, sediment and process interpretations. Continued subaqueous fan growth results from settling of river-derived sediments from suspension and downslope sediment dispersal by episodic gravity flows, apparently fed by underflows from the river.