While the sands settle out to form beaches, the clays remain in a suspension at approximately 8% solids concentration (Cs. mass of solids mass of total) or 3.8% by volume (specific gravity of fines being m2.2) Within a decade, these fines will settle to C 3520. but not appreciably settle or consolidate thereafter, even for significant dam heights (~80 m), and even after 50 years