Abstract: “Sable Island, an arcuate bar of unconsolidated sand about 24 miles long, is the only emergent point on the outer continental shelf off northeastern North America. A paleosol, probably as old as 6800 years B.P., covers aeolian sand deposited when most or all of Sable Island Bank was subaerially exposed during lower stands of sea level. These Pleistocene are orange to red as a result of coatings of ocherous hematite on quartz grains. Abrasion and selective transportation during the Holocene have removed the iron-stain coating and altered the mineralogical composition of the sands above the paleosol. Lateral distribution of these sands suggest that (1) the north and south sides of the island are subject to different physical conditions and that (2) the net sediment movement is toward the northeast. Beach and dune sands can be differentiated only on the basis of texture. A mean grain size versus sorting plot is useful when large-scale movement of sediment with little selective sorting takes place, but when sediment has been subjected to prolonged selective sorting a skewness versus kurtosis plot is more useful. The backbone of the island, two parallel east-west trending dune chains, occupies the median position between strong winter winds from the northwest and gentle summer winds from the southwest. The interaction between wind and waves, both seasonal in character, causes cyclical movement of sediment from the island to the sea and back again. Although Sable Island is being slowly displaced toward the east, it is not being destroyed as predicted in previous studies.”
