夏里组沉积初期羌塘盆地发生大规模海退，海水由北向南退出，在此基础上，形成了北羌塘盆地以碎屑岩充填为主、南羌塘盆地以碳酸盐岩沉积为主的沉积特点．根据地面露头及分析化验资料，夏里组沉积相类型有滨海相、三角洲相、台地相及盆地相．滨海相有高能砂质类型海岸和低能泥质类型海岸两种类型，广泛发育于北羌塘盆地．三角洲相仅局限于盆地西部中央隆起带北侧．南羌塘盆地由北向南依次发育以碳酸盐岩沉积为主的局限台地、开阔台地、盆地相 During the initial sedimentation of the Xiali Formation, the Qiangtang basin experienced a large-scale regression and the seawater exited from north to south. On the basis of this, the northern Qiangtang basin was dominated by clastic rocks, while the southern Qiangtang basin was characterized by carbonate deposition The main sediment characteristics. According to the surface outcrop and analysis of laboratory data, the sedimentary facies of the Xiari Formation are of the facies facies, delta facies, platform facies and basin facies. The coastal facies have two types of high-energy sandy coast and low-energy muddy coast, which are widely developed in the northern Qiangtang basin. The delta phase is confined to the north side of the central uplift zone in the western part of the basin. Southern Qiangtang Basin developed from north to south in order to carbonate sedimentary-based platform, open platform, basin facies