摘要
An ice core which is 5 annual layers contained was drilled at Dongkemadi branch glacier,middle of I anggula Mts. The chemical analysis shows the obviously similar variations of the concentra-tions of major canons and anions versus depth. The similarities are ascribed to the same types ofaerosols that most of the ions concentrate and coexist. For instant, the aerosols traosported from thearid regions outsides north of the Tibetan Plateau as well as the high-mineralized saline lakes on theplateau are probablythemain sources of the major ions. However, profile of nitrate is unique comparedlth other species. Themaximum of theconcentrations of the major tons, i.e. Na+, MgZ+, Ca'*, andK+, coincides well with the depths of dirty layers, which correspond the accmulation of snowfallsfrom the end of ablation season to late spring, the concentration peaks of theselayers arepossibly dueto dry deposition during the “rare precipitation and dust storm” season. The contrast between the pro-files of chemical species and stratigraphy of ice core suggests that the disturbance of meltwater to thechemical records of ice core is not negligible. we are confirmed therefore by the records of ice core, thatthe continental air masses prevailingly controlling atmospheric environment over Tibetan Plateau mayreach somewhere south of Tanggula Mountain.