Optically Stimulated Luminescence Chronology For DG02Core Of Gahai Lake In East Of Qaidam Basin

As an important source of information on climate change, lake sediments has itsindispensable advantages, thus in the study of past climatic and environmental changes and theimportance attached to it. Ever since the late19th century, scholars have been distributed in lakesof various sizes around the world have done a lot of research, which includes Europe and thePleistocene lake basin, Maar Lake in Europe, Lake of Qinghai-Tibet plateau, study Lakes laminaein geochronology, pollen analysis, magnetic susceptibility, granularity, and δ18O、δ37Cl、δ13Corgisotopic analysis. In the lake sediment in the study of dating methods also constantly enrich, hasnow developed includes14C dating, electron spin resonance and uranium-series (U/Th) Act andthe luminescence dating, dating of volcanic ash and other dating methods.Gahai Lake is an inland closed lake, located in the De Ling Ha basin in northeast ofQinghai-Tibet plateau, which are very sensitive to climate change responses, is the ideal place forstudying regional environmental response to global change. In recent years, some scholars havedone some research on palaeo-climate environment change in Gahai Lake, but only use theAMS14C for dating, dating methods are single. This paper use the Single Aliquot Regeneration(SAR) protocol of Optically Stimulated Luminescence (OSL), We tested7samples of OSL age ofDG02drilled in Gahai Lake, Contrast with the previous estimates of AMS14C age in GahaiLake and Hurleg lake. It is concluded that:1, Through the De value, the frequency distribution and the analysis of the sun retreated,combining previous OSL dating in lake sediment dating method of application, Single AliquotRegeneration (SAR) protocol of Optically Stimulated Luminescence (OSL) can be applied to thelake sediment, and can obtain more reliable age data.2, The age of Gahai Lake in DG02range at2.22±0.17ka to25.55±2.08ka, and increasingage with depth, indicate that the drilling from LGM stage to the Holocene deposits.3, Contrast with AMS14C age of DG02and DG03drilled in Gahai Lake, we found that: Thetwo hole age is consistent, But the two drilling have many age inversions. The14c age of GahaiLake younger than its OSL age about3.5-10ka, which in the0-1000cm14c age older than theOSL age, but after the1000cm,14c age younger than OSL age，and with the increase of thedepth, the age gap is increasing. The reasons for this difference may be due to “reservoir effect” affect the upper age, and the lower part sediments may be polluted by new carbon-related, but thespecific reasons for the pollution is not clear.