Climate Evolutiom Since Late Pleistoncene In Muli Region Of Qilian Mountain

Qilian Mountain is a region sensitive to climate changes,the ecologicalenvironment is fragile,particularly in the study area Muli,due to extensive coalmining, has caused some damage to the ecological environment.Therefore,understand and grasp the evolution of the climate characteristics of the region notonly to play a guiding role in protecting the environment, but also provide for thenatural gas hydrate storage, development and the utilization of effective climateenvironmental basis.Late Pleistocene contains the most recent and the duration of the last glacial age,so the study area since the late Pleistocene climate research papers as of greatimportance.This paper selects five profiles to measuring and sampling, Basis of theanalysis on granularity,magnetic susceptbility,pollen records and oxides,with OSLage determination test,we can get the following points:1.The characteristics of Quaternary sediments in the study area is as follows,thelower part is gravel layer or sands with gravel layer,In the middle is clay layer andclay with gravel,on the top is humus layer.2.The granularity,pollen records and oxides of PM1is consistent,From bottomto top is divided into3stages.3.The climate evolution from the late Pleistocene in the study area can bedivided into6stages as follows:The middle of late Pleistocene (88.25-52.00KaB.P.):worm and dry period.The middle-late of late Pleistocene（52.00-47.01KaB.P.):cold and moist period.The late of late Pleistocene （47.01-31.31KaB.P.):worm and dry period.The later of late Pleistocene （31.31-26.32KaB.P.):worm and moist period.The end of late Pleistocene （26.32-15.61KaB.P.):cold period.The end of late Pleistocene till now（15.61Ka B.P.-0KaB.P.):climate fluctuation period.