Grand Erg Occidental The mean elevation of the Grand Erg Occidental is about 500 m, on average higher than the elevation of the Grand Erg Oriental, but not as high as the neighboring Tademaït to the southwest. This desolate region is a practically uninhabited area; there are no permanent villages and there are no roads crossing it. Grand Erg Occidental The Grand Erg Occidental (, al-ʿIrq al-Gharbī al-Kabīr), (also known as the Western Sand Sea) is the second largest erg in northern Algeria after the Grand Erg Oriental. It covers an area of approximately . The sand dunes in the erg are formed
Issaouane Erg which can take hundreds of thousands of years to form; mesoscale dunes (including the stardunes), which form on the mega dunes; and yet smaller ones which migrate over the bigger ones. In the NASA images, the light-blue spots in the valleys between the dunes (which are red from iron oxide) are "sabkhah", or salt flats, left after the evaporation of accumulated water. Neolithic artifacts, sculptures and paintings have been found in the Issouane Erg. from the Kiffian culture. The Issaouane Erg contains oil; the Tifernine oilfield is explored by the Algerian state oil company Sonatrach, which began developing the oilfield