In Suffolk County the glacial moraine and glacial outwash behave very similarly for engineering purposes. The lacustrine deposits deposits differ from the moraine and outwash in that they are composed of fine-grained particles, mostly of silt and clay size. Muck is composed of organic matter in varying states of decomposition. Beaches are found along the shores of Long Island, and they vary in particle size form cobblestones to fine sand. Dune land is associated with beaches, but is mostly fine sand piled into mounds by wind action.
Tidal marsh consists of varying proportions of organic material and sand.
Soil Survey of Suffolk County, New York.