There are two large indentations of the coast - the Gulfs of Tehuantepec and California.
In addition to these seas notice must be taken of the subordinate marginal features, such as gulfs and straits.
The plain lying between this coast range and the Andes dips below sea-level in the gulfs of Ancud and Corcovado (average width, 30 m.).
Gulfs may be classified according to their origin as due to fractures of the crust or overflowing of depressed lands.
Gulfs formed by the overflowing of depressed lands lie upon the continental shelf, e.g.
