Gobi, Drainage and soils

Aridity in the Gobi depends on the relative chalkiness of the soil and has been aggravated by the strong mountain structure to the west. The lakes correspondingly have shrunk, leaving a series of terraces considerably farther from and higher than the present shorelines. Indeed, Lakes Orog and B��ntsagaan, in the easternmost Mongolian Altai, and Lake Ulaan, in the