The shallow submerged extension of continent is called the continental shelf. It is the shallowest part of the ocean with depth varying between 20 to 600 m. Its width vary from one ocean to another ranging between 65 to 75 km. The width of the shelf is often related to slope of the adjacent land. It is wide along the low lying land and narrow along the mountainous coasts. Nearly 70% of continental shelves are covered with thick deposits of silt, sand, mud and sediments derived from the land.
