The use of Models in the Interpretation of the Effects of Base-Level Change on Alluvial Architecture

  1. N. D. Smith2 and
  2. J. Rogers3
  1. S. B. Marriott

Published Online: 17 MAR 2009

DOI: 10.1002/9781444304213.ch20

Fluvial Sedimentology VI

Fluvial Sedimentology VI

How to Cite

Marriott, S. B. (1999) The use of Models in the Interpretation of the Effects of Base-Level Change on Alluvial Architecture, in Fluvial Sedimentology VI (eds N. D. Smith and J. Rogers), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304213.ch20

Editor Information

  1. 2

    Department of Geosciences, 214 Bessey Hall, University of Nebraska, Lincoln, NE 68588-0340, USA

  2. 3

    Cape Town, South Africa

Author Information

  1. School of Geography and Environmental Management, University of the West of England, Bristol, Coldharbour Lane, Bristol BS16 1QY, UK

Publication History

  1. Published Online: 17 MAR 2009
  2. Published Print: 7 OCT 1999

ISBN Information

Print ISBN: 9780632053544

Online ISBN: 9781444304213

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Keywords:

  • controls on river systems and alluvial successions;
  • use of models in interpretation of effects of base-level change on alluvial architecture;
  • sediment accumulation on floodplains;
  • fluvial response to base-level change;
  • use of models - examine effects of base-level change;
  • effects of base-level change on alluvial architecture;
  • sequence of operations in computer-simulation model;
  • outcrop of late cretaceous fluvial sediments in Languedoc basin;
  • general pattern of sandbody geometry and connectedness

Summary

Base-level changes occur over a broad range of time-scales and may result from several interacting factors. As a result, relative sea-level has changed considerably over geological time, at times of intense glaciation and at times when the Earth was ice-free. Several models have been proposed that examine the effects of base-level change on river systems and the expected impact on alluvial architecture. These models tend to be qualitative and their aim was to give guidance in the interpretation of seismic stratigraphy. From Allen's pioneering work in the 1970s, a new generation of alluvial-architecture models has evolved. These are now solved by computer and provide an insight into a range of intrinsic and extrinsic influences on the development of fluvial sequences. None of these quantitative models, however, has been used to examine the effects of base-level change on alluvial architecture. This paper reviews literature on fluvial response to base-level change, then illustrates the use of a computer model developed by Crane in 1982 to examine this response in terms of a fluvial sequence. The resulting computer output of the alluvial architecture is then compared with a conceptual model and field data from southern France and Argentina. The general pattern of sandbody geometry and connectedness, simulated by computer, is in broad agreement with the conceptual model and with the outcrop patterns described. It is considered unreasonable to suggest that the models discussed would be applicable to all fluvial systems, because base-level change is only one of many extrinsic and intrinsic influences.