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THE COMPARISON OF LANZHOU LOESS PROFILE WITH VOSTOK ICE CORE IN ANTARCTICA OVER THE LAST GLACIATION CYCLE 总被引:4,自引:0,他引:4
Loess near Lanzhou in the late Pleistocene is very sensitive to climatic fluctuations. The Beiyuan terrace profile in Linxia City, of which the curve of susceptibility tallies with the trend of isotopic curves of Vostok 2083 m ice core in Antarctica, is 35m thick. There are five layers of paleosols under Malan loess(L_1). Upper three layers (S_(1-a),S(1-b)and S_(1-c) correspond to three warm stages in last interglaciation, Interstadial of Last Glacial (C stage in Antarctic ice core)was clearly recorded in the Beiyuan profile, in which three layers of paleosols and two of loess were formed. The lowest section of the profile belongs to penultimate glaciation, in which fossils of cold-drought-resistant mammal and mollusc have been discovered. 相似文献
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The major Quaternary climatic deterioration of the Lushan area occurred mainly in LatePleistocene when a periglacial environment prevailed on the high summits above 1000 m a.s.l.with resulting frost shattering and gelifluction. The data from sporo-pollen analysis, fossilfauna, paleosols and the elevation of the snowline in the ice ages prove that conditions for thedevelopment of the glaciers did not exist in the Lushan during early and middle Quaternaryperiod. Evidence of former glaciation has not been found in the study on the type sedimen-tary sections in Yejialong and Dajiaochang gully. There are many relict landforms belong-ing to hot and humid tropical climate rather than to glacial one. The problems of the land-form development of the Lushan are also discussed. 相似文献
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青藏高原东北边缘晚新生代沉积物磁组构的初步研究 总被引:2,自引:0,他引:2
通过临夏盆地晚新生代以湖相为主的沉积物磁组构特征的初步研究表明,沉积物磁组构特征的变化很可能同青藏高原的阶段性隆升有关,正是由于青藏高原的隆升才造成盆地水系格局的,入湖水流方向的改变,从此意义上说,临夏盆地晚新生代沉积剖面各段磁组构特征的变化可能蕴含了青藏高原隆升的信息,沉积物磁组构参数值的变化无疑会给我们对青藏原隆升的认识提供了新的思路和证据。 相似文献
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Together with their British friends, the authors made a field investigation in the Karakoram Mountains in Pakistan for radio-echo sounding on the Ghulkin Glacier during the summer of 1980.Four transverse sections and one longitudinal section including thirty-two measurement points have surveyed on the glacier tongue. The ice-depths at the points have been calculated, and measurement errors analysed on the basis of experimental data.The history and present status of radio-echo sounding are briefly reviewed and appraised in this paper. 相似文献
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运用因子分析法处理青藏高原东北边缘临夏盆地近30MaB.P.以来新生代沉积物的氧化物含量提取的气候演变的序列及特征与孢粉分析结果基本一致,即在第三纪大部分时间中,虽有冷干与暖湿的交替变化,但气候状况相对稳定;进入上新世后,气候不稳定性显著增加,表现为冷干与暖湿大幅度、频繁地交替,至第四纪早期,才又表现出相对冷湿的环境特征.这一变化特征一定程度上反映了东亚季风由上新世前不显著至上新世中逐步建立,直至第四纪早期稳定建立的动态过程.气候自第三纪以来的重大调整,同青藏高原的阶段性隆升有密切关系. 相似文献
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