中国低纬度地区中更新世以来冰川发育与成因探讨

Development and Cause of Glacial since Middle Pleistocene in Low Latitude of China

青藏高原东南缘和台湾地区是国内外第四纪学者研究的热点地区,对研究冰川发育与构造和气候(气温和降水)的关系具有重要意义。该文以冰期系列为切入点,通过研究分布在中国低纬度地区的玉龙雪山、拱王山、点苍山、台湾山地的冰期系列,运用多种手段确定的隆升速率论证构造对冰川发育尤其是对冰期系列的主导作用。使用Ohmura的公式P=645+296T+9T2计算玉龙雪山、拱王山、点苍山、台湾玉山的现代理论雪线分别为5 193m、5 000m、5 068m、3 953m,考虑构造抬升的末次冰期雪线降低值分别为1 220m、1 423m、1 630m、928m,末次冰期6-8月平均气温比现代的降低值分别为7.3℃、8.5℃、9.8℃、5.6℃,分析数据显示:台湾山地的气温条件不如青藏高原东南缘山地有利于冰川发育,但是台湾山地同样发育大规模的末次冰川作用,说明降水是控制台湾冰川发育的主导因素。

The southeast of the Tibetan Plateau and Taiwan are both the hot spots for domestic and overseas Quaternary stud- ies, they play important roles in discussing tectonic movement and climate （temperature and precipitation） impact on glacial de- velopment. Base on glacial sequence, according to study the glacial sequence among Yulongxueshan, Gongwangshan, Diancangs- ban and Taiwan mountain, which distribute in low altitude in China, uplift rate determined by multiple means to demonstration the tectonic movement influence the glacial development especially the glacial sequence. Combined with Ohmura＇s formula of the relationship between the annual precipitation and atmospheric temperature at equilibrium line altitude （ELA）, the present theo- retical ELA in Yulongxueshan, Gongwangshan, Diancangshan and Taiwan mountain are respectively 5 193 m, 5 000 m, 5 068 m and 3 953 m, and consider the tectonic movement, the ELA depression in the last glacial cycle are 1 220 m, 1 423 m, 1 630 m and 928 m, the temperature depression are 7. 3℃, 8. 5℃, 9. 8 ℃ and 5.6 ℃responding. From the data, it is concluded that the tem- perature in Taiwan mountain is not in favor of developing glacial than the southeast of the Tibetan Plateau. However, Taiwan mountain also discover big extent glaciation, so the temperature and precipitation both have an impact on the glacial develop- ment.