| Under cosmic-ray flux, stable cosmogenic nuclides and radioactiveisotopes are created in geomorphic surface, for example 3He 10Be 26Al14C 41Ca 21Ne 36Cl. The concentration of cosmogenic isotope in rock surface is a function of age, production rate, erosion rate and uplift rate. Using this model, we can calculate the exposed age. This technique for surface dating is ripe now and often be used, especially cosmogenicisotopes 10Be and 26Al being used to dating. Cosmogenic isotopes Be wasused to date the glacial geomorphic surface of Qinghai-Xizang Plateau inthis paper. We used quartzite grains for Be because qrartzites are closeto being pure Si02, quartzite is very resistant to weathering and easyfound.Retreating samples included extracting Be from quart grains andmeasuring 10Be/9Be ratio by AMS. Quart grains were picked out in the 0.25to 1.0 mm size fraction and remove atmospheric Be by confining to theouter portion about 20%-30%. These samples were made into tergers for analysis by AMS at the Tandetron AMS facility at Gif-sur-Yvette, France.Experimental precision was indicated by three group data. CD 10Be/9Be ratio of three blank samples: 0.125*10-13 0.029*10-13, 0.037*10-15. The lowest ratioAMS can measure is 10-15. The maximum error of atmospheric contaminationis 0.2% during experimenting. (2) Be concentration of two samples takingfrom same rock surface: 6.88886*106 atoms/g 6.810176*106 atoms/g. Theerror is 1.15%. (3) Be concentration of two same samples: 4.491689*10?atoms/g 4. 494642*106 atoms/g. The error is 0.07%. It can be judged that the experimental data is accurate.There are three variates during dating: exposure age, erosion rateand uplift rate of plateau. The erosion altitude 9 cm was determined by the glacial rock surface under big stone and surround rock surface. The erosion rate of granite can be calculated : 6. 42*10 cm/a( through samples: X8 X9) . The erosion rate can be used to other granite samples because they are so near. The erosion rate of samples X7 X13 being taken from the old moraine can be restricted using the maximum erosion rate and the minimum erosion rate. During calculating, the mean value of erosion convergent to 1. 53*10 cm/a.There are different ideas about Qinghai-Xizang Plateau uplift. In brief, there are two situations. One is Qinghai-Xizang Plateau reached modern height before Quaternary, the other is Qinghai-Xizang Plateau uplifted stage to the height since Quaternary. But there are different ideas about Qinghai-Xizang Plateau uplifting rate. The uplift rate changes from 0. 133 cm/a -0.4 cm/a in 800 ka BP.According to the idea of uplift early, it can be calculated that the old moraine was formed in 459. 42 ka BP, the glacial rock surface was formed in 122. 5 ka BP and the roche moutonnee was formed in 18. 3 ka BP. According to the uplift rate of 0. 133-0.4 cm/a, the old moraine was formed in 610 ?0ka, the glacial rock surface was formed in 140? ka and the roche moutonnee was formed in 18. 6?. 2 ka. Because moraine remained when ice flourished age was over, and glacial rock surface began to expose during ice age is over, they indicate the glaciation event are different. The old moraine near Kuzhaore was formed in MIS16(uplift late) or Misl2(uplift early). The glacial rock surface on the independent hill near Laolinkou Daoban was formed in MIS6. The roche moutonnee in the north of Mountain Tuershang was formed in MIS2.Normally , the distance glacial reached is further and the height of glacial is bigger, the scale of ice age is bigger. The old moraine formed in the last but two glaciation and the glacial rock surface formed in theIVlast but one glaciation can be remained, that indicate the scale of ice age is the last but two glaciation, the last but one glaciation and the last glaciation from the largest to the least. The glacial rock surface formed in the last but one glaciation on the independent hill indicates that the last glaciation was not reach the height. It also indicate that the idea about successive ice sheet includ...
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