Erg (landform) and western Asia, and Central Australia. In South America, ergs are limited by the Andes Mountains, but they do contain extremely large dunes in coastal Peru and northwestern Argentina. They are also found in several parts of the northeast coast of Brazil. The only active erg in North America is in the Gran Desierto de Altar () that extends from the Sonoran Desert in the northwestern Mexican state of Sonora to the Yuma Desert of Arizona and the Algodones Dunes of southeastern California. An erg that has been fixed by vegetation forms the Nebraska Sandhills (). Sand seas and dune
Erg Ferradj Erg Ferradj Erg Ferradj () is a town and commune in Abadla District, Béchar Province, in western Algeria. According to the 2008 census its population is 4,406, down from 4,670 in 1998, and an annual population growth rate of -0.6%, the second lowest in the province. The commune covers an area of . Erg Ferradj lies at an elevation of to the west of an extensive palm plantation covering 3000 hectares lying along the western side of the Oued Guir. The rocky hills of the hamada are found on both sides of the river, but are more dramatic on the