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白马雪山地处横断山脉腹地,对于重建西南季风影响区的环境变迁以及探讨冰川作用特点具有重要科学意义。这里保留着典型的晚第四纪冰川侵蚀地貌,其中冰川槽谷发育特征明显。本文运用抛物线形态参数、梯级宽深比、形态比率等定量分析冰川槽谷的研究方法,对保存在白马雪山主峰扎拉雀尼(5429m)东北坡的两条简单冰川槽谷的形态特征进行分析。采用7个典型剖面的形态特征参数与其他地区对比,探讨冰川槽谷发育的可能影响因素如水热条件、冰川性质、冰川规模、岩性特点、冰川作用时间等。结果显示:白马雪山冰川槽谷抛物线形态参数b值为1.779,明显小于冰川性质相同的螺髻山(1.835),主要是由于区域降水条件的不同所造成的差异,而与冰川性质不同天山乌鲁木齐河源区(1.825)冰川槽谷的形态特征的差异,可能与冰川规模、作用时间以及岩性条件密切相关;梯级宽深比中槽谷形态参数沿程变化可以反映冰川流动过程中的动力变化,梯级宽深比中的形态参数A_f和B_f值最大处对应的谷肩位置接近雪线位置。根据槽谷谷肩的位置确定末次冰期早期/中期的雪线高度为4140m,这与用地貌法如冰斗底部高程法、侧碛堤最大高度法和冰川末端至冰斗后壁最大高度法等综合确定的雪线高度4092m基本一致。因此,在冰川槽谷发育的冰川作用区,用槽谷谷肩的海拔高度估算雪线高度可以成为一种比较可靠的确定古雪线方法;白马雪山的冰川槽谷形态参数b-FR的特征表明,即使是海洋性冰川作用区也不符合Hiran和Aniya提出的山地冰川模式,但运用b-FR相关关系可以很好的反映冰川的侵蚀过程。白马雪山地区冰川侧蚀作用导致槽谷坡降值较小,底部较平坦宽阔,呈现出相对完整的U型形态。此外,用形态比率FR值也可以验证雪线的位置高度。
Baima Snow Mountain is located in the hinterland of the Hengduan Mountains, which is of important scientific significance for reconstructing the environmental change in the SWMZ and exploring the features of the glacier. Here retained the typical Late Quaternary glacial erosion landscape, including glacial trough valley development characteristics. In this paper, quantitative analysis of glacial troughs using parabolic morphological parameters, step-width-depth ratio, morphological ratio and other analysis methods were used to analyze the morphological characteristics of two simple glacial troughs stored in the northeast slope of Zalaitanye (5429m) . By comparing the morphological characteristics of seven typical sections with those of other regions, the possible influencing factors of glacial trough development such as hydrothermal conditions, glacier characteristics, glacial scale, lithology characteristics and glacial action time are discussed. The results show that the parabola shape parameter b of Glacier valley is 1.779, which is obviously smaller than that of Luoji Mountain (1.835) with the same glacier, which is mainly caused by the difference of regional precipitation conditions, but different from the glacier nature of Urumqi river source region (1.825) The differences of the morphological characteristics of glacier troughs may be closely related to glacier scale, duration and lithology conditions. The variation of the shape parameters along the troughs of the cascade can reflect the dynamic change of glacier flow, The position of the valley shoulder corresponding to the largest depth of the morphological parameters A_f and B_f is closer to the snow line. According to the location of valley valley shoulder, the snow line height in the early / mid-last glacial period was 4140m, which is consistent with the method of topography such as ice bucket bottom elevation method, side moraine dike maximum height method, Determine the snow line height of 4092m basically the same. Therefore, estimating the height of snow line at the glacial valley where glacier trough develops may be a reliable method to determine ancient snow line. The characteristics of the glacial trough valley shape parameter b-FR in Baima Snow Mountain indicate that, Even the glacially active glacier does not conform to the mountain glacier model proposed by Hiran and Aniya, but the use of the b-FR correlation can well reflect glacial erosion. Glacier erosion in the Baima Snow Mountain region resulted in a smaller slope depression value and a more flat bottom, presenting a relatively complete U-shape. In addition, using the form ratio FR value can also verify the location of snow line height.