Issaouane Erg confined to basins. Sand in the Issaouane Erg, below the level of the sand dunes, has accumulated to a depth of 20 to 30 meters. It has barchan dunes as well as star dunes of 300 to 430 meters high. The presence of both barchan dunes (which form due to unidirectional winds) and star dunes (which form when winds from various directions deposit sand) "suggests that wind regimes have changed over time". NASA's "Earth Observatory" notes all three types of erg dunes are present in the photos of the Issaouane Erg taken from the International Space Station: stationary mega dunes,
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