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贺兰山(3556m)是中国东部存在确切第四纪冰川遗迹的山地之一,是我国季风区与非季风区、温带草原与荒漠草原的分界线,对于研究中国东、西部冰川发育特点以及青藏高原边缘山地冰川发育与气候和构造之间的耦合关系具有十分重要的科学意义.野外地貌调查与室内光释光(OSL)、加速器质谱碳十四(AMS14C)对冰川、黄土以及湖相沉积物年代测定结果显示,在贺兰山主峰周围海拔2800m以上保存着古冰川侵蚀与堆积地貌,第四纪冰川发生的时限较晚,时代上限为末次冰期中冰阶,对应深海氧同位素MIS3中期(43.2±4.0ka)、末次冰盛期(LGM,~18ka)、晚冰期(12.0±1.1ka)和新冰期(3.4±0.3ka),冰川作用的阶段性明显.采用深海氧同位素曲线(MIS)代表共和运动(150ka)以来的冰川平衡线变化,并用末次冰盛期的平衡线(2980m)以及现代理论雪线高度值(4724m)作为平衡线的最大振幅,以3.5mm/a作为贺兰山体的抬升速率,探讨了末次冰期以来贺兰山山体高度与冰川作用之间的关系,并与黄土-古土壤等反应气候环境变化的指标对比,认为贺兰山地区第四纪冰川作用是山体的构造抬升与气候条件耦合的结果,即“共和运动”之后山体抬升到与末次冰期气候耦合的高度,开始发育冰川.
Helan Mountain (3556m) is one of the mountains with the exact Quaternary glacial relics in eastern China. It is the dividing line between monsoon and non-monsoon regions, temperate steppe and desert steppe in China. It is of great significance to study the characteristics of glaciers in the east and west of China and the edge of the Qinghai- The relationship between glacier development and climate and tectonics in mountainous area is of great scientific significance.Outline, Glacier, Loess and lacustrine sediments dating by field survey and indoor OSL and accelerator mass spectrometry carbon 14 (AMS14C) The results show that the erosion and accumulation of paleo-glaciers preserved above 2800m above the main peak of the Helan Mountain, the Quaternary glacier occurred later, and the upper limit of the age was the middle-ice period of the last glacial period. Corresponding to the mid-MIS3 (43.2 ± 4.0ka) (LGM, ~ 18ka), late glacial (12.0 ± 1.1ka) and the new glacial (3.4 ± 0.3ka), the phases of the glaciation are obvious, and the deep sea oxygen isotope curve (MIS) ), And the maximum amplitude of balance line with the balance line of the last ice age (2980m) and modern theoretical snow line height (4724m) is 3.5mm / a as the Helan Mountain The relationship between Helanshan mountaineering height and glacier effect since the last glacial period was discussed. Compared with the index of climate change of loess-paleosol response, it is concluded that the Quaternary glaciation in Helan Mountain area is the result of tectonic uplift and climate The result of the conditional coupling, that is, after the “Republican Movement,” the mountain was lifted to the level of the coupling with the last glacial climate, and the glacier began to develop.