Fluvial Distributary Channels in the Fletcher Bank Grit (Namurian R2b), at Ramsbottom, Lancashire, England
- J. D. Collinson and
- J. Lewin
Published Online: 29 APR 2009
Copyright © 1983 The International Association of Sedimentologists
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
- Published Online: 29 APR 2009
- Published Print: 7 FEB 1983
Print ISBN: 9780632009978
Online ISBN: 9781444303773
- fluvial distributary channels – Fletcher Bank Grit, Ramsbottom, Lancashire, England;
- cliff-face exposures;
- channel filling;
- traction currents
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.