Sedimentary rock the sedimentary cover can become unstable, causing turbidity currents. Turbidity currents are sudden disturbances of the normally quite deep marine environment and can cause the geologically speaking instantaneous deposition of large amounts of sediment, such as sand and silt. The rock sequence formed by a turbidity current is called a turbidite. The coast is an environment dominated by wave action. At a beach, dominantly denser sediment such as sand or gravel, often mingled with shell fragments, is deposited, while the silt and clay sized material is kept in mechanical suspension. Tidal flats and shoals are places that sometimes dry because
Rock Sand to his best position of second on the list of leading sires. On his four-year-old debut, Rock Sand ran against Sceptre again in June over the Derby course and distance in the Coronation Cup, a race which also featured the first meeting between Rock Sand and his contemporary Zinfandel, a colt whose engagements in the previous year's classics had been rendered void by the death of his owner Colonel Harry McCalmont. Zinfandel won easily from Sceptre, with Rock Sand third. Rock Sand avoided Zinfandel for the remainder of the season and was unbeaten in his remaining five races. He won