Grain-Size Distribution of Overbank Sediment and Its Use to Locate Channel Positions

  1. M. Marzo and
  2. C. Puigdefábregas
  1. M. J. Guccione

Published Online: 14 APR 2009

DOI: 10.1002/9781444303995.ch14

Alluvial Sedimentation

Alluvial Sedimentation

How to Cite

Guccione, M. J. (1993) Grain-Size Distribution of Overbank Sediment and Its Use to Locate Channel Positions, in Alluvial Sedimentation (eds M. Marzo and C. Puigdefábregas), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303995.ch14

Editor Information

  1. Barcelona, Spain

Author Information

  1. Geology Department, Ozark Hall-#118, University of Arkansas, Fayetteville, Arkansas 72701, USA

Publication History

  1. Published Online: 14 APR 2009
  2. Published Print: 16 SEP 1993

ISBN Information

Print ISBN: 9780632035458

Online ISBN: 9781444303995

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Keywords:

  • Grain-size distribution of overbank sediment;
  • identification of flood plain deposits;
  • knowledge of source of that sediment or the channel position;
  • Grain size-distance relationships;
  • Grain size of overbank alluvium decreases with distance

Summary

Studies of three rivers show that overbank alluvium decreases in grain size with distance from a channel source. In a first approximation of this relationship, sand and silt fractions best illustrate the decrease in grain size of overbank sediment derived from small streams where it is deposited less than 100 m from the source. In contrast, silt and clay fractions best illustrate this decrease in grain size for a large river (the Mississippi) where the sediment is deposited at distances greater than 1 km from the source. However, the clay fraction can only be used if the accretion rate is sufficiently rapid for pedogenesis not to affect the clay content. For both small and large streams with overbank sediment from a source less than 10 km distant, the fine silt fraction best illustrates the decrease in grain size with distance.

Overbank alluvium may be used to determine the position of the channel which served as a source of that sediment. The sediment grain size and the grain size–distance plot can be used to determine the distance between a sample site and a source channel, assuming a simplistic diffusion model for sediment transport and deposition. Multiple sample sites may be used to locate the channel position.