. Collected reprints / Atlantic Oceanographic and Meteorological Laboratories [and] Pacific Oceanographic Laboratories. Oceanography 92 30-i 20 10- ? 2nd ORDER RIDGES Q3rd ORDER LINEATIONS. AZIMUTH (°) Histograms of orientations of large-scale current lineations (third order) and of crestlines of second-order ridges. The ripples were symmetrical, with broadly rounded tops. They were inferred to be degraded wave ripples. The largest and best developed ripples were located on the upper flanks and smaller more degraded ripples on the lower ridge flanks. This pattern probably
. Collected reprints / Atlantic Oceanographic and Meteorological Laboratories [and] Pacific Oceanographic Laboratories. Oceanography 92 30-i 20 10- ? 2nd ORDER RIDGES Q3rd ORDER LINEATIONS. AZIMUTH (°) Histograms of orientations of large-scale current lineations (third order) and of crestlines of second-order ridges. The ripples were symmetrical, with broadly rounded tops. They were inferred to be degraded wave ripples. The largest and best developed ripples were located on the upper flanks and smaller more degraded ripples on the lower ridge flanks. This pattern probably reflects a grain-size gradient decreas- ing down the slope. The A2 zones, subjacent to the rippled bottoms may represent areas where ripples were once present but have since been completely degraded. The amount of coarse material (> 2 mm) is minor; generally less than 1% and consisting mostly of shell material. Fig. 10 shows the percentage of coarse material (> 2 mm) across the submersible traverse. Higher percentages of shell material appear to be associated with the better developed ripples on the upper flanks. In general, shell material from Aj and A2 zones consists mostly of Echinoid fragments; but locally on some higher parts of the ridge, razor clam (Ensis) debris appears more abundant. Bottom type B occurs on the lower flanks of the seaward portions of the two ridges. The sequence Ai —A2 —B can be explained as an effect of grain size decreasing downslope, with the very smooth B zone representing the depositional of fine material on the seaward portions of the ridges. This fine flank material of zone B may reflect the fallout of wave-winnowed sand from the ridge crests, or sand swept on to flanks from troughs. Zone C bottom may represent the outcropping of Holocene/Pleistocene shell-capped backbarrier units discussed above. These outcroppings are correlated with broad dark bands on the side-scan sonar records ( and 9). They occur in the broad portion of
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