| 希夏邦马峰—珠穆朗玛峰地区地貌与环境演化问题探讨 |
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| 引用本文： | 刘勇,邓晓峰.希夏邦马峰—珠穆朗玛峰地区地貌与环境演化问题探讨[J].冰川冻土,1998,20(1):79-84. |
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| 作者姓名： | 刘勇 邓晓峰 |
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| 作者单位： | 兰州大学地理科学系(刘勇)，中国科学院兰州冰川冻土研究所(邓晓峰) |
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| 摘 要： | 希夏邦马峰－珠穆朗玛峰地区是新生代以来，在欧亚板块与印度板块碰撞的地质背景下，迅速隆升起来的极高山地区．进入第四纪以来，强烈的构造隆升，使这些山地上的冰川进退、河流发育和湖泊变迁都发生了重大变化，带来整个地貌格局的变化．倒数第二次冰期时，亦即聂聂雄拉冰期的鼎盛时期，本区发育了巨大的冰帽，覆盖了整个地区．末次冰期的冰川以长大的山谷冰川和小冰帽为主要特点．在末次间冰期，河流侵蚀能力增强，位于山地南坡的河流进行强烈的溯源侵蚀，破坏了山脉的完整性，并对北坡的河流进行劫夺，从根本上改变了本区的地貌格局．到了全新世后期、新冰期到来之际，佩枯错的水位也达到了其在地质历史上的最高水位和最大面积，高出现今湖面整整１００ｍ．此后，由于朋曲河的溯源侵蚀和劫夺作用，上游流域面积减少，水源补给逐渐丧失，水域迅速收缩，水位降低．
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| 关 键 词： | 冰期 环境演化 河流劫夺 构造地貌 希夏邦马锋 |
An Approach on the Geomorphological and Environmental Development in the Xixiabangma-Qomolangma Area |
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| Abstract: | The Xixiabangma-Qomolangma area has uplifted rapidly since Neocene, under the geological background of collision of the Eurasia Plate with the Indean Plate. With the dramatical tectonic uplift in Quaternary, advance/retreat of glaciers, development of rivers and change of lakes all underwent dramatic shifts, and induced the entire change of geomorphological pattern. In the Penultimate Glaciation, i. e. the maximum Nieniexiongla Glaciation, large scale of glaciers or small ice sheet developed in this area, covering all the area. The glaciers in the Last Glaciation were mainly large and long valley glaciers and small ice sheet. In the Last Interglaciation, the erosion ability of rivers enhanced, the rivers in the south side of the Himalayas made strong backward erosion, cut into the core of the mountains, destroyed their entirety, captured rivers in the north side, and changed fundamentally geomorphological pattern in this area. In the Climatic Optimum of middle Holocene, the Peiku Lake got the highest water level and the widest area in its geological history, when the water level was just 100 m higher than that at present. Afterward, water supply became less and less, water area shrinked rapidly, and water level reduced with the backward erosion and capture of the Pengqu River. |
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| Keywords: | glaciation environmental evolution capture of river |
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