COSMOGENIC ISOTOPE ¹⁰Be DATING FOR KUZHAORI MORAINE IN DAOCHENG ICE CAP

The Daocheng Ice Cap which is on the southeast of Shaluli Moutain had appeared as a large-scale glacier in Quaternary. Howevrer, there are few dating data available in the study area. In this article, we chosed three samples form the Kuzhaori moraine in the southern margin of Daocheng Ice Cap and used Cosmogenic Isotope ¹⁰Be exposure dating methord to date the exposure age of the moraines. It is found that:(1) the exposure time of the oldest moraine at Kuzhaori is 714±8.0~529±8.0 kaBP. The exposure age of D moraine is 121±2.9~114±2.9 kaBP. and the exposure age of DC moraine is 47±1.3~43±1.3 kaBP. Exposure ages give an estimate of the timing of initial glacier retreat, so we can deduce that E moraine, D moraine and DC moraine are the results of glacier advance in MIS 16、MIS 6 and MIS 3b, according to the climate changes deduced from deep-sea oxygen isotope isotopic records and other dating data. (2) The retreat of glacier is a gradual process. We double-Checked the dating data of sample E. It shows that the cosmogenic isotopes dating technique is an effective method in dating moraine samples.