. Collected reprints / Atlantic Oceanographic and Meteorological Laboratories [and] Pacific Oceanographic Laboratories. Oceanography 292 COASTAL SEDIMENTATION ridges. A full understanding of the genesis of these coastal sand bodies must await more detailed field meas- urements of the responsible flows. Storm-Induced Inner Shelf Ridge Fields Ridge fields on the inner shelf floor continue their mor- phologic identity and their characteristic pattern of grain-size distribution (Fig. 34). Relief continues at 10 m, and slopes for isolated inner shelf ridges are very similar to those o
. Collected reprints / Atlantic Oceanographic and Meteorological Laboratories [and] Pacific Oceanographic Laboratories. Oceanography 292 COASTAL SEDIMENTATION ridges. A full understanding of the genesis of these coastal sand bodies must await more detailed field meas- urements of the responsible flows. Storm-Induced Inner Shelf Ridge Fields Ridge fields on the inner shelf floor continue their mor- phologic identity and their characteristic pattern of grain-size distribution (Fig. 34). Relief continues at 10 m, and slopes for isolated inner shelf ridges are very similar to those of shoreface-connected ridges. Scour continues in troughs; the erosional surface cut by shoreface trans- lation extends beneath the ridges and is locally exposed in trpugh axes (Swift et al., 1972a,b). Generally, how- ever, it is veneered with a few decimeters of coarse, pebbly sand, overlaid by finer sand. The coarser sand is commonly exposed in elongate windows through the finer sand veneer. Sidescan sonar records suggest that the finer sand is moving as ribbonlike streamers over a coarser lag substrate. Ridge crests consist of medium to fine, well-sorted sand, with cross-stratified horizons (Swift et al., 1972a; Stubblefield et al., 1975). Flanks consist of fine to very fine sand and are distinctly asymmetrical in their textural pattern; seaward flanks are notably finer, and are locally steeper than landward flanks. Crestal sands, however, may be distinctly coarser than. the flank sands of either side, probably a response to winnowing by wave surge. The inner shelf ridges themselves appear to be in a state of slow transit, wherever there is a bathymetric time series adequate to test this hypothesis (Figs. 35 and 36). The pattern of movement is a fairly consistent one, in which both shoreface-connected and isolated inner shelf ridges move along similar trajectories. Where the angle of convergence of the ridge crest with the shoreline is fairly large, the ridges are moving down
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