Reconstruct The Paleoenvironment Of Sylvite Mineralization In Lop Nur Since 30000 Years

Lop Nur,as an important research area in the aird inland region of Asia,is located in the hinterland of Eurasia and the easternmost part of Tarim Basin.It is one of the typical extreme arid areas in China and even in the world.Many studys have shown that the environment changes in this area remarkable since Quaternary.In addition,the strong evaporate resources,which is an important sylvite production base in China.Due to the special and unique characteristics of Lop Nur,Lop Nur has become an important information carrier of global environmental change.It is of great theoretical and practical significanc to reconstruct the environmental background of sylvite mineralization in Lop Nur area since 30000 years ago.In the study,the TDP4 and DHB profile are taken as the research object.The dating test,element test and grain size test are carried out.The environmental background of Lop Nur is reconstructed.TDP4 profile cover from 27.9 to 18.1 cal.ka B.P..Environmental changes of TDP4 profile can be divided into three stages.Between 27.9-26.2cal.ka B.P.the climate was drought from wet.From 26.2 to21.3cal.ka B.P.the climate was wet and cold in the early stage,the climate was drought and cold in the later stage.21.3-18.1cal.ka B.P was wet period.The DHB section encompassed the periods from 15.3 to 6.3 cal.ka B.P..The sequence of environmental evolution can be divided into four stages.From 15.3 to 14.4 cal.ka B.P.conditions was drought.Between 14.4-11.75 cal.ka B.P climate conditions was wet in the early stage,in the later stage,the drought become worse.During11.75-7.48 cal.ka B.P.the climate was warm and wet.From 7.48 to 6.3 cal.ka B.P.the climate was drought.About 15.0 cal.ka B.P.cold event,about 14.3?12.9?10.8?9.3cal.ka B.P.dry event,about 8.4 cal.ka B.P.cold dry event and about 7.0 cal.ka B.P.cold dry event are recorded in the profile.The dry climate,aboudant sylvite source and closed tectonic environment are the basic conditions for the formation of potash deposits.In the dry climate condition,salt lake evaporation,lake water shrinkage constantly,resulting in the increase of Cl,S elements content,so that its sylvite source constantly evaporated out of the surface,with the accumulation of time,the climate continues to be dry,sylvite resources continue to be evaporated and enriched,thus providing rich sylvite resources.Therefore,the study on the environmental evolution of Lop Nur since 30000 years has provided scientific basis for the formation of sylvite significance for the rational development and utilization of salt resources.