河北、内蒙古中低山区发现罕见的冰臼群

Rare Moulin Swarms Discovered in the Medium-Low Mountains Areas in Hebei and Inner Mongolia

冰臼是冰川流行的有力证据之一,也是古气候、古环境变迁的历史见证。已有的资料表明,冰臼大多数发育于冰谷底部及冰床之上,规模不大、数量不多。而在我国河北、内蒙古中低山区发现的冰臼群,绝大多数分布于由坚硬的花岗岩组成的山脊和山峰上。目前发现并经过实地调查过的6处冰臼群,冰臼总计有400～500个以上,分布在海拔650～1500m左右。冰臼大小一般为0.5～2m,深0.2～1m左右。最大冰臼口宽约10m,深约3.5m;最小冰臼口宽及深度均在数厘米左右;最深冰臼约5m,而口宽仅0.12m。冰臼多呈圆形、椭圆形或不甚规则形,呈口小、肚大和底平为主要特征。河北、内蒙古中低山区大量冰臼群的发现,笔者认为中国东部中低山区在第四纪早期确实曾发生过大规模冰川活动。这一发现对该区和全球古气候、古环境演化研究,提供了十分重要的依据,对开发旅游资源也有着重要意义。

Moulins are powerful evidence for glacial development as well as a historic witness to paleo-climatic and paleoenvironmental shifts. Available data indicate that most moulins are developed on the bottom of glacial valleys and glacial beds and that they are small in size and limited in number. But the moulin swarms discovered in the medium-low mountains areas of Hebei and Inner Mongolia are mostly distributed on the mountain crests and peaks of hard granites. Moulins of five moulin swarms discovered and investigated on the spot now amount to more than 400~500, which are distributed at elevations of ca. 650~1500 m above sea level. These moulins are generally 0. 5~2 m in diameter and 0. 2-1 m or so in depth. The largest moulin is about 10 m wide and about 3. 5 m deep, whereas the mouth width and depth of the smallest moulin are both about a few centimeters; the deepest moulin is about 5 m in depth with a mouth width of only 0. 12 m. Most moulins are round, elliptical or irregular in shape with a small mouth, a large belly and a flat bottom. The discovery of large numbers of moulin swarms in the medium-low mountains areas of Hebei and Inner Mongolia provides evidence that large-scale glaciation did took place in the early Quaternary in medium-low mountains areas of eastern China. This discovery provides very important grounds for the study of the global paleoclimatic and paleoenvironmental evolution and also has great significance for the tourist resources and economic development.