Study On The Glacial Period And Glacier Scale Since The Late Pleistocene In The Middle Section Of The Taniantaweng Mountains

Taniantaweng Mountains is located in the west of Hengduan Mountains,with Tanggula Mountains in the northeast and Nianqing Tanggula Mountains in the west.The geographical position is very important.The terrain in the study area is complex and diverse,with alpine and valley distribution.Modern glaciers and glacier landforms are extensive in the study area.The Yuqu River flows through it,the terrain is slightly cut and the glacier landforms are well preserved.It is an ideal area for restoring the past environmental changes.The Yuqu River flows through it,the terrain is slightly cut and the glacier landforms are well preserved.It is an ideal area for restoring the past environmental changes.This paper examines the Late Quaternary glacial sedimentary geomorphology of Quzha Valley,Qinggulong Valley,Juequ Valley and the Ruqu Valley in the middle section of the Taniantaweng Mountains.Three dating methods,¹⁰Be exposure dating,ESR and OSL,were used to dating different glacial sediments in the study area at the same time.Three methods cross-dating and correction each other to establish absolute Glacier Evolution sequence.The chronological measurements of different glacial deposits in the study area were carried out using the ¹⁰Be exposure dating method,ESR and OSL dating methods.The three methods cross the dating and correct each other to establish an absolute glacial evolution sequence.At the same time,based on the glacier dynamic model and the GLaRe tool,the scale of the glacier in the study area was reconstructed,and the scale of the glacier at different glacial periods in the study area was restored.Combining the glaciation sequences with the glacier extent evolution process,the climate-tectonics coupling effect on Quaternary glacier development in middle and low latitudes is validated.The conclusions are as follows:?1?Based on the results of ¹⁰Be exposure age,ESR and OSL,studies have shown that at least four glaciers have occurred since the late Quaternary in the middle section of TaniantawengMountains:MIS6?90.73±8.71ka?,MIS3?30.99±2.97ka?,LGM?15.43±1.46ka²1.26±2.04ka?and eH?8.18±0.78ka⁸.54±0.82ka?.?2?Comparing the glacial advance age of the study area with the Qinghai-Tibet Plateau and its surrounding mountainous areas,we find that there are great differences in the glacial advance age of the mountainous areas in different regions.The Penultimate Glacial Period?MIS6?and the previous glacial processes mainly distributed in the Pamir Plateau,Himalaya-Gangdise Mountains,Kunlun Mountains and the central part of the Tibet Plateau.Since the late stage of MIS6,the glacial transgression remains are mainly preserved in the Boduizangbu Basin in the southeastern part of the Tibet Plateau and between middle section of Taniantaweng Mountains and the Hengduan Mountains.In the mid-MIS3,the glacial advance mainly occurred along the Tianshan-East Pamir Plateau in the northwestern margin of the Tibet Plateau,along the Himalayas-Nianqingtanggula-Tanggula-Hengduan-Kunlun Mountains in the southern and southeastern margins of the Tibet Plateau,as well as the Altun Mountains on the northeastern edge of the plateau-the Qilian Mountains and the Taiwan Mountains.The Last Glacial Maximum?MIS2?has a large number of chronological data in the Tibet Plateau and its surrounding areas,which have the characteristics of integrity and universality.The Holocene glacial age data are relatively few.Based on the chronological results,it is suggested that the glacial advance may be related to the 8.2ka BP cooling event.?3?Based on the glacier dynamics model and using GLaRe tools,the glacier scale of the four glacial advance stages in the middle section of Taniantaweng Mountains was reconstructed.The results show that the average thickness of glaciers from the late penultimate glacial period to the early Holocene glacial period is 190 m,110 m,67 m and 50 m,the area is21 km²,6 km²,5.35 km² and 1.21 km²,and the volume is 4.002 km³,0.661 km³,0.35 km³ and0.06 km³.In summary,it is found that since the penultimate glacial period in the middle section of Taniantaweng Mountains,the scale of glaciers has gradually decreased,the thickness of glaciers has gradually thinned and the area has gradually decreased.At the same time,by comparing the glacier scale of the penultimate glacial period in the Quzha and Juequ valleys,it is found that different topographic conditions have an important influence on the development of glaciers under the same glacier action.Compared with the glacier extent in the surrounding areas,it is found that the glacier extent changes in the middle section of Taniantaweng Mountains and the western part of China generally show the characteristics of gradual decrease.