TL Dating of Malan Loess in Gansu Province

TL dating technique is of great advantage for determining the initial time of storing energy（T;）in an object to be analyzed.The sample is required to have undergone at least onethermal event,permitting all the residual storage to release.As a result,TL dating techniquehas found wide application in geochronology of pottery.The determination of T;of loess ismainly based on the fact that fine particles of which loess is composed will lose their storage inthe process of transportation by wind.In our experiment TL dating technique was adopted to determine the ages of fine quartzgrains,and the results were corrected for those of shine-fading experiment.TL dating of Malan loess specimens from Mt.Gaolanshan,Liugouhe near Lanzhou,Mt.Qijiadashan in Jingning and Baichaoyuan in Huining gave the age values of 2.6±0.1,3.6±0,3.4.7±0.5 and 10.0±0.6×10;yr,respectively.The values indicate that the Malan loess began de-positing in Late Pleistocene,but the initial time and acumulation rate are different under dif-ferent morphological conditions from place to place.