10Be distribution and uranium-series dating of salt samples from salt playae in the Chaidamu Basin,Qinghai, northwest China

The distributions of cosmogenic nuclide¹⁰Be in the upper and lower salt units from a core (36.4°N, 94.5°E) in the Chaidamu Basin, Qinghai, China have been measured by means of accelerator-mass spectrometer. The comparison of these¹⁰Be results measured on salt and detritus fractions shows that the geochemical behaviour of¹⁰Be is detritus-phile. In this area¹⁰Be influx is different in the past tens of thousands of years, which is suggested to be related to climatic fluctuations during late Pleistocene. It seems that¹⁰Be influx is higher in the humid climate environnent than in the dry climate environment. The²³⁰Th-age estimates of two salt units have been determined. The corrected ages of the lower unit show a climate shift from humid to dry at about 50 Ka ago in this area.