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喜马拉雅山珠穆朗玛峰-希夏邦马峰地区是青藏高原南部现代冰川集中发育区之一,古冰川遗迹亦十分丰富,是研究第四纪青藏高原冰川形成和演化的关键区,一直备受地貌和第四纪环境研究者的关注.应用原地宇宙核素10Be暴露年龄测试技术,对采自希夏邦马峰西北佩枯岗日拉曲谷地冰碛垄上的冰川漂砾进行年代学研究;结合冰川地貌分析方法,对古冰川平衡线高度(ELA)和气候特征进行探讨.结果表明:末次冰期时,拉曲谷地冰川扩张,发育了山麓冰川,拉曲Ⅰ冰川面积99.9 km2,平衡线海拔5 620 m;拉曲Ⅱ冰川面积97.6 km2,平衡线海拔5 600 m;与现代平衡线高度相比,拉曲Ⅰ和拉曲Ⅱ的平衡线分别下降380 m、400 m.拉曲在末次冰期存在多次冰进,拉曲Ⅰ的10Be暴露年龄在42.1～22.3 ka;拉曲Ⅱ的10Be暴露年龄在18.6～14.8 ka.根据地貌法恢复末次冰期拉曲Ⅰ平衡线高度的温度为-10.7℃,拉曲Ⅱ为-10.6℃,降水量分别为251～461 mm和261～480 mm,显示出当时雪线高度的温度状况和现代冰川雪线高度的温度状况接近,但是降水比现在少得多,冰川气候类型为亚大陆型,印度季风减弱带来的水气变少.
Himalayas Mount Everest - Shishapangma peak area is one of the concentrated glaciers of modern glaciers in the southern part of the Qinghai-Tibet Plateau, and is rich in ancient glaciers. It is a key area for studying the formation and evolution of glaciers on the Qinghai-Tibet Plateau during the Quaternary. Quaternary environmental researchers are concerned with the geochronology of glacial boulders collected from moraine ridges collected from the Rhyti valley in Pekui hill, northwestern Xibabangma peak, using the on-site universe radionuclide 10Be exposure age test technique. In the last glacial period, the glaciers in the Lhache Valley expanded, the foothills of the glacier developed, and the area of Latch Ⅰ glacier was 99.9 km2. The altitude of the balance line 5 620 m; Latch Ⅱ glacier area is 97.6 km2, and the balance line is 5 600 m above sea level. Compared with the height of modern equilibrium line, the balance line between LST1 and LST1 decreases by 380 m and 400 m, respectively. There were multiple ice inlets, and the exposure age of 10Be in La Qu I was 42.1 ~ 22.3 ka and that of 10Be in La Qu II was 18.6 ~ 14.8 ka. The temperature at which the equilibrium height of La Qu I was restored in the last glacial period was -10.7 ℃ , Pull song Ⅱ is -1 0.6 ℃ and precipitation of 251 ~ 461 mm and 261 ~ 480 mm, respectively, showing that the temperature of the snow line at that time is close to that of the modern glacier snow line, but the precipitation is much less than that of today, and the glacial climate is of continental type , India’s monsoon winds bring less moisture.