一九二六年,在北京举行的中国地质学会学术年会上,一位身材魁伟、三十开外的年轻学者宣读了一篇内容新颖的科学论文。他从地壳岩层的变化,海水进退的差异,讲到大陆的大规模水平运动,进而提出一个引人入胜的地壳运动理论——地球自转速度在地质年代时快时慢的变化,是地球表面构造形态变更的主要因素。讲者侃侃而谈,论又有据,述之成理,引起与会者的强烈反响。这位学者就是当年任北京大学地质系主任的李四光教授。他宣读的这篇著名论文《地球表面形象变迁之主因》,在地质学中引进一个新的方 In 1926, at a academic annual meeting of the Chinese Geological Society held in Beijing, a young, 30-year-old young scholar read out a novel scientific paper. He talked about the large-scale horizontal movement of the continent from the change of the crustal strata and the seawater advance and retreat, and then he put forward a fascinating theory of crustal movement - the rapid and slow change of the earth’s rotation speed during the geologic age is the change of the structure and structure of the Earth’s surface structure The main factor. Speakers talked about, on the basis of data, described as reasonable, aroused strong repercussions of the participants. The scholar was Professor Li Siguang, then director of the department of geology at Peking University. He read this famous paper “the main reason for the image of the Earth’s surface changes,” in the introduction of a new geology