Taibai In Mountain Periglacial Geomorphologic Characteristics And Environmental

In recent years,rely on the Qinghai Tibet Plateau and its relevance edge mountain,geomorphology and quaternary workers of Quaternary glaciers in China have established the systematic understanding in occurrence,development,distribution and the corresponding mechanism and from the new perspective of theories,they proposed that coupling effect of climate and tectonic results changes in mountain body environment.As an important carrier of Quaternary environment changes,Periglacial geomorphology has important implications for the ancient and modern mountain environment.As an important mountain range in case of the geographic boundaries of the "bridge" transition of the mountain and the partition of north and south,Qinling,the mountain lying in Central China reaches to Weihe Valley in the north and reaches Bashan Hanzhong Basin in the south.Its main ridge Taibaishan with an elevation of 3767.2 m,the highest peak in the east area of China.Main body of this mountain is composed of granite,marble and metamorphic rocks,and the peak grew in the tertiary planation surface.Massive residues developed by frost weathering are widely distributed and periglacial geomorphology development is very typical.(1)Based on the field investigation in peak of Qinling Taibai mountain,it has been clearly observed that there are landscapes developed in the altitude above 3000 m as follow:block field,stone stream and stone slopes,rock glacier,and underground blind rivers,well developed talus and scree,ice edge rock column and stone fort,nivation depressions,stone ring and other typical periglacial landforms and there are loess layers developed in the presence of periglacial as observed.(2)Due to the structure,lithology,slope direction and the height of the mountain in different,periglacial geomorphology types and characteristics are different,freeze-thaw weathering gravel landform is widely developed,in the southern slope of which,we can see block field,rock glaciers,and underground rivers,rubble and debris heap a lot of typical development,on the north slope of periglacial rock pillars and stone fort,stone river and stone Liupo was developed typicaly.(3)Using method of moraines chronology,landform compiling and the comparison of regional enviroment in Taibai Mountain glacial sequence combined with climate in North China evolution evidence at least three periglacial action period of Taibai Mountain in late Pleistocene middle and late stage of late Pleistocene and Holocene periods have been confirmed to experience,naming as Hall periglacial periods(30-50 ka);Taibai periglacial periods(12-28 ka);in Temple ice margin period(0.25 ka).(4)The evolution characteristics of Taibai mountain environment is conform with the changing regulary of the East Asian monsoon region in late Pleistocene environment and provide possibolity to perform research on Asian monsoon system and mountain movement in ice/interice period.Through the comparison we can conclude that in the late Quaternary environment in Taibai Mountain,glacial and periglacial staged a stage line succession,glacial and periglacial periods start time is responsed mutually,reflecting a certain regularity.From contrasting glacial evolution in Japan,the Russian Far East,North Korea and others we can see the same monsoon system under the environment of the common,but certain differences can be seen due to the difference in geographical position of heat and water.The results show that the factors of climate,structure,latitude and the location of the land and sea and others control the last glacial stage of the East Asia monsoon region,distribution and time stage.Under the control factors'influence,low altitude mountain in East Asia does not appear earlier behavior than the last glacial period of glaciation.Through the analysis and discussion of glacial features in East Asia monsoon region it can be found,due to the differences in geographical location as a result from hydrothermal conditions,in many mountain in the East Asian monsoon region,the phenomenon of periglacial geomorphology development is widespread,and only a few mountain development have termicnal glacial.Periglacial and glacial development there has correlation and difference,and in reality the conclusion of mistaking the ice margin for the glacial relics is not consistent with the overall regional environmental evolution characteristics.