Direct observation of longitudinal furrows in gravel and their transition with sand ribbons of strongly tidal seas
Belderson, R.H.; Wilson, J.B.; Holme, N.A. (1988). Direct observation of longitudinal furrows in gravel and their transition with sand ribbons of strongly tidal seas, in: de Boer, P.L. et al. (Ed.) Tide-influenced sedimentary environments and facies. Extended versions of papers presented at the Symposium on Classic Tidal Deposits, held August 1985 in Utrecht, Netherlands. pp. 79-90 In: de Boer, P.L. et al. (Ed.) (1988). Tide-influenced sedimentary environments and facies. Extended versions of papers presented at the Symposium on Classic Tidal Deposits, held August 1985 in Utrecht, Netherlands. D. Reidel Publishing: Dordrecht. ISBN 90-277-2622-1. ix, 530 pp., more |
| Authors | | Top | - Belderson, R.H.
- Wilson, J.B.
- Holme, N.A.
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| Abstract | Longitudinal furrows in gravel are developed in tidal seas where there are strong currents, a shortage of sand and a relatively smooth sea floor. Television, photographic and side-scan sonar observations of the sea floor in the English Channel show that variable amounts of coarse sand and/or fine gravel are transported along the axes of the furrows. With decreasing current speeds these develop, through a transition zone, into sand ribbons. The degree of faunal growth on the sea floor is related to the degree of abrasion by sand in transit. The furrow floors are almost devoid of faunal cover. They are flanked on one side by a strip of floor with a diverse and stable faunal assemblage, and on the other by a strip of floor with a much more gradual transition back to a diverse and stable fauna. The secondary flow mechanism usually proposed as causing the furrows must take into account this asymmetric arrangement, as well as their branching nature. |
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