Fluvial Distributary Channels in the Fletcher Bank Grit (Namurian R2b), at Ramsbottom, Lancashire, England

  1. J. D. Collinson and
  2. J. Lewin
  1. Steve A. Okolo

Published Online: 29 APR 2009

DOI: 10.1002/9781444303773.ch34

Modern and Ancient Fluvial Systems

Modern and Ancient Fluvial Systems

How to Cite

Okolo, S. A. (1983) Fluvial Distributary Channels in the Fletcher Bank Grit (Namurian R2b), at Ramsbottom, Lancashire, England, in Modern and Ancient Fluvial Systems (eds J. D. Collinson and J. Lewin), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303773.ch34

Author Information

  1. Department of Geology, The University, Keele, Staffordshire ST5 5BG, UK

Publication History

  1. Published Online: 29 APR 2009
  2. Published Print: 7 FEB 1983

ISBN Information

Print ISBN: 9780632009978

Online ISBN: 9781444303773

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Keywords:

  • fluvial distributary channels – Fletcher Bank Grit, Ramsbottom, Lancashire, England;
  • cliff-face exposures;
  • palaeochannels;
  • channel filling;
  • traction currents

Summary

A working quarry in the Fletcher Bank Grit (Namurian R2b) provides excellent cliff-face exposures over a horizontal distance of some 800 m. Vertical and lateral relationships between five major delta distributary channels and their associated bay-fill sequences can be studied.

All five channels are thought to be of low sinuosity, and the lowest three cross-cut one another. The bed forms that produced the channel fills were sandwaves, dunes, ripples and flat beds which participated in variable proportions in four of the five channels. The other channel was probably filled by accretion on alternate bars.

Vertical sedimentation is considered the dominant channel filling mechanism for channels 1, 4 and 5 while side-filling appears to have dominated during the infilling of channels 2 and 3. There is probably a greater channel density in the lower part of the sequence than in the top, suggesting that channel switching may have been more frequent during the deposition of the sediments in the lower part.