CHARACTERISTICS, ORIGIN AND EVOLUTION AGES OF AEOLIAN SAND IN THE SAHELIAN REGION OF MALI

Key words: 
• Sahelian region of Mali /
• aeolian sand /
• material souree /
• desertification

Abstract: The Sahelian region of Mali is one of the areas seriously affected by sandy desertitication in the world.Widely distributed aeolian sand lays a material basis for the development of sandy desertification.Aeolian sand in the region is dominated by fine sand, followed by very fine sand.Sand materials contained in various sand dunes are different in grain size to a certain extent and the mineral compositions of dune sand are dondnated by stable and extreme stable minerals, with high stability and maturity.Aeolian sand in the region mainly comes from the reachvation of ancient sand dunes, the transportation of recent runing water and the sand supply of dry lakes and arroyos.Since the Pliocene this region has experienced four major evolution periods of aelian sand, namely from the Pliocene to the early Quaternary, last glacial period, the Holocene and present.