Grand Erg Occidental 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 by the wind, and can be up to high. Certain crescent-shaped dunes, known as barchans, are actually mobile; the wind can push these dunes as much as 20 to 30 m (65-100 ft) in one year. It is a desert natural region that receives less than 50 mm (1,96 in) of rainfall per year.
Erg Chech in Aoulef District, Adrar Province, Algeria, is named 'Erg Chech'. About of meteorites were collected in the Chergach strewn field, located in the Erg Chech north of Taoudenni, during the fall and winter 2007. Desert nomads reported that during daytime in July 2007 several detonations were heard over a wide area, a smoke cloud was seen and several stones fell from the sky, however no fireball was reported. Ouled Bleila was the finder of the first meteorites, but he died in October 2007 in a car accident on his way back from the trip to the Chergach strewn field. According