The Optically Stimulated Luminescence Chronology And Environmental Significance Of Nebkhas In The Qaidam Basin

The Qaidam Basin in the northeast of Qinghai Tibet Plateau has been a hot area of global climate change research and aeolian sedimentary geomorphology because of its unique geographical location and climate characteristics.All kinds of Aeolian sedimentary geomorphology are widely distributed in the basin.Compared with the study of crescent dunes and linear dunes in the central part of the basin,a large number of researches on the desert loess paleosol deposits in the eastern part of the basin are still lacking.Many of the nebkhas predecessors,is also more concentrated in the morphological characteristics of shrub evolution,ecological function and fertility,and the distribution of research area is quite uneven,mostly concentrated in Xinjiang,Inner Mongolia and other coastal areas,the southern Qaidam Basin nebkhas little attention.In this paper,using the OSL dating technique and AMS¹⁴C dating method for the study of Southern Qaidam basin to nebkhas,chronology and its environmental significance in the area of nebkhas.The main conclusions of this paper are as follows:?The first time in this area using optically stimulated luminescence dating of SAR-SGC?Single Aliquot Regeneration,Standardise Growth Curve?of K-feldspar in the test,the experimental verification system,as well as potassium feldspar dating results in comparison with AMS¹⁴C,explains the research dating of potassium feldspar is fully applicable to the area of nebkhas.?The starting time of the nebkhas began to develop in the late Holocene,and did not find the development of an earlier era shrub,the research results and in Qaidam Basin and other different types of sand dunes in different lakes integration study,study and research results from the eastern region of the ring,the late Holocene the most drought the stage,the area of nebkhas development is likely to be the response to drought of the late holocene.?The research in the same layer sampling OSL samples compared with AMS¹⁴C,OSL were significantly underestimated quartz,potassium feldspar pIRIR's there may be some residual dose effect.The difference between OSL and ¹⁴C in the same layer samples of some nebkhas in this area is quite different.It is probably not the problem of the dating technology itself,but the unique shrub and dune evolution and sedimentary mode in this area.?The evolution mechanism of shrub and dune in this area is rather complicated.There are still many uncertainties in using single nebkhas to correlate with climate change.