(i) During the pre-Cambrian era, there was a large depression in which the sediment was deposited and a block of crystal rock known as the Peninsula Plateau came out of this depression and never submerged again. This stable land has behaved as a rigid and inflexible block throughout its geological history and is often compared to a horst. (ii) Lagoons are saltwater ’lakes, separated from the main sea by sand bars and spits, ex: Chilka lake. Delta: In the lower course of the river, the river divides itself into several channels known as distributaries and in between these distributaries, sediments are deposited forming a triangular-shaped feature which is known as Delta, ex: Ganga Brahmaputra delta.