Chemical sedimentary sequence of Lop Nur salt lake in Xinjiang and its controlling factors

Located in the eastern part of the Tarim Basin,Lop Nur Lake is one of the largest playa lakes in the world. Although the overall chemical sedimentary sequence of the salt lake appears quite simple,represented by gypsum-glauberite (very thick)-halite (rather thin),the detailed variation of the sequence is rather complex and can be divided into nine zones according to ages of the strata. The chemical sequence of Lop Nur salt lake is remarkably different from many non-marine and marine chemical sedimentary sequences except for that of Tertiary paleo-salt lake in Jianghan Basin,Hubei Province,which shows some similarity with the sedimentary sequence of Lop Nur salt lake. The differences are probably related to such factors as regional climate,substance sources and tectonic environments. This special chemical sequence should have been the response to global climate changes and tectonic movements. Therefore,the coupling of continuous drying and supply variation might have been responsible for the formation of the special and complex chemical sedimentary sequence in Lop Nur salt lake.