EXTENSION AND SUBDUCTION OF THE MESO-CENOZOIC TARIM BASIN AND THEIR RELATIONSHIP WITH MANTLE PLUME

Since the Permian,the Tarim Basin had undergone basinal extension,subduction and intro-continental orogeny.Basinal extension and subduction was related to activity of mantle plume,formation and evolution of mantle plume resulted in geothermal decreasing of lithosphere in the basin.A huge thermal dome structure was firstly formed in continental crust due to rising of hot mantle plume during the Early Permian,and graben and fault basin were further formed.During the Late Permian to Triassic,intra-continental down-warped basin was formed in the central part of the basin as a result of thermal decreasing from mantle after eruption of mantle plume material in the Early Permian;however,strong compression was occurred from centre to outsides because of raising of mantle material,Tianshan and Kunlunshan were fastly uplifted and thrusted towards the basin,and two foreland basins were formed respectively.From the Jurassic to the Cretaceous,it was a thermal decreasing period in the basin,as a result,intra-continental down-warped basin was formed.It was a relative fast period for geothermal decreasing during Cenozoic,which corresponded with continental convergence,subduction,thrust-nappe and collisional orogeny in the area.Mountain system around the basin was uplifted continously and the basin was subducted.Just because of formation and evolution of mantle plume,it resulted in inner basinal extension,subduction and intra-continental orogeny.The protobasin in Meso-Cenozoic includes transverse extensional basin (Early Permian),intra-continental foreland basin and down-warped basin (Late Permian-Triassic),intra-continental down-warped basin (Jurassic-Cretaceous) and late foredeep basin(Cenozoic).