王明业等同志这篇论文提供了不少西藏高原上古冰川沉积以及其他遗迹的资料。从这些遗迹的分布来看,肯定有一个时期冰川的范围远比现代为大,那时冰川会从一些山谷通过一些低的山口漫溢到另一些山谷中,会覆盖广大的山麓地区,甚至达到盆地的中心。也可以想见某些宽平的山顶上可能有平顶冰川或所谓冰帽覆盖。在这种情况下,冰川的厚度一定也比现代为大,冰川的类型也更复杂的多。但是对于西藏高原这样一个广大的地区来说,作者等的观察范围以及获得的资料究竟还是非常有限,在达到的地区内也未见到有巨厚的,延续很广的冰碛物存在,所以据此即说除雅鲁藏布江谷地和金沙江、澜沧江、怒江的峡谷外西藏高原断续出现的冰盖是相当普遍的(虽然作者等也声明说和格林兰、南极洲的冰盖不一样),结论似乎下得太早。所引waxler的关于晚更新世雪线下降随的资料仅适用于一般海洋性气候的冰川作用区,是否能用到象西藏这样大陆性很强的地区是值得怀疑的。但是无论如何,作者等的资料是很宝贵的,关于西藏高原古冰川覆盖类型的问题,目前也确实还难说孰是孰非,所以我们还是把本文发表出来,以供对西藏古冰川研究的参考。

On the Tibetan Plateau, remnants of the quaternary glaciation are of general oc-curence. Cirques, U-shape valleys, glacial-scoured lakers, till plains, terminal moraines, and drift boulders are wide spread features down to 4200 m in altitude. The authors believe that there was once a fairly continuous ice cover on the Tibetan plateau in late pleis-tocene. Here after the snow-line was raised, and the glaciers retreated gradually to their present positions. The reasons are two-fold:(a) a general warming of the world climate, (b) dessication of Tibet due to further uplift. The latter is evidenced by the obvious shrinkage of many lakes on the plateau. By correlating the moraines of this glaciation with the terrace of Zi-Ling Tsangpo and Yamdrok, we reach at the conclusion that this great Ice Cover was of late Pleistocene in age. Since that time the glacier retreated in three recessional stages: 1. forming Yamdrok Lake ................................……4400 m. 2. forming terminal moraines in Cano Chu Valley ............……4650 m. 3. forming moraines on Cano-La Col ........................……4950 m. Respective recessional moraines are also discovered in the valley of Drokar Chu on the northern slope of Chumulanma.