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The Preliminary Study Of Quaternary Glacier In Middle Tenasserim Chain

Posted on:2017-06-23Degree:MasterType:Thesis
Country:ChinaCandidate:L ChaiFull Text:PDF
GTID:2310330488472000Subject:Physical geography
Abstract/Summary:PDF Full Text Request
Tenasserim chain,located in the transitional zone between the southeast of Tibetan Plateau and Yunnan-Kweichow Plateau,we can provide vital basis for rebuilding the evolutionary history of glacier effect in Hengduan Mountain range and the uplifting mechanism of Tibetan Plateau by deeply research.The relies of the Quaternary period glacier is surly reserved above the elevation of 4200m of Tenasserim chain's middle range.Judging from the grouping character of physiognomy and the grouping trait of precipitation where developed in the research area,once here developed a little bigger scope foothill glacier where flowed into Yuqu valley,and it was limited between the mountain valley and the valley glacier and cirque one where in the origin.This paper applies the means of the outdoors inspect and indoor laboratorial analysis primarily surveying the Quaternary period erosional physiognomy and accumulated ones in the research area,as well as the electron spin resonance dating(ESR)to establish the glacial sequences.The results are as follows:1.Erosion landscape of glacier There conserves several big glacier troughs between the elevation of 4800-5200 m,of which the cross profile manifest U,about 1-2 km wide,extending length 4.5-25 km;development in the study area typical cirque,horn,blade ridge,candy,and ice glacial lake,including cirque development is big enough,the typical form.Using natural breakpoint method,this paper will study area above 3900 m ice bucket is divided into four classes,namely,3900-4670 m,4670-4920 m,4920-5060 m,5060-5360 m four altitude range,different altitude belt cirque morphological differences are more obvious.Slope to the distribution of the ice bucket mainly by the influence of the difference of precipitation and structure and terrain factors on the cirque distribution also has the control function,slope direction,toward the radiation distribution is mainly controlled to control the temperature factor.2.The glacier accumulation landforms Glacial deposits mainly stored in the tank bottom,the trough valley exit and piedmont,form a clear glacial till four sets.The development in the Qing Gulong village,near the 4 trough valley and the Bagu village in 6 trough valley glacier debris preservation is better.In addition to the neo-glaciation/Little Ice Age(corresponding to the deep sea oxygen isotope stage 1,abbreviated MIS 1),the remaining three glacial till electron spin resonance(ESR)dating results the Penultimate glaciation(MIS 6,MIS= Marine Oxygen Isotope Stage)during the Middle Pleistocene(192±51 ka,207±45 ka,207±29 ka),the middle stage of the last glacial cycle(MIS3,55±8 ka-54±9 ka)and the last glacial maximum(MIS2,25±1 ka-38±6 ka)during the Last Pleistocene.Combining different stages of glacial till sedimentology,environmental magnetism and element geochemical shows that glaciers in the middle Tenasserim chain at least four times.3.Compared with the surrounding mountain quaternary ice age series shows that the study area special geographical location gives its special ice development condition,and it conforms to the overall law of the development of the quaternary glacial ice,also glaciers have certain differences in the size of different stages.it closely linked with the Tibetan plateau and its surrounding mountain since the quaternary climate and tectonic conditions,and the glacier is the result of the coupled action of tectonic and climate.
Keywords/Search Tags:Tenasserim chain, ESR dating, glacial sequence, glacial landforms
PDF Full Text Request
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