地文期及其在新生代黄土和古地理研究中的意义

侵蚀循环理论和地文期理论是地貌学的重要的基本理论。中国大陆在古近纪之前构造比较稳定，以低平的准平原地貌为主。白垩纪末至古近纪初，喜马拉雅运动拉开了序幕，中国的古地理环境发生了巨大的转变，逐步形成了高原、高山和盆地构成的复杂地貌景现。侵蚀循环和地文期理论是研究上述地质历史的有效方法和重要手段。在讨论侵蚀循环问题的一些新认识、新思考的基础上．初步探讨地文期在中国新生代黄土和古地理环境研究中的意义，希望加强研究并使其发挥更大的作用。

Physiographic stage and its significance in the study of Cenozoic loess and paleogeography

The theories of erosion cycles and physiographic stages are important theories of geomorphology. The continent of China was relatively stable for a long time before the Paleogene, and its geomorphology was dominated by low and flat peneplains. From the end of the Cretaceous to the beginning of the Paleogene, the Himalayan movement was the prelude to radical changes of the paleogeographic environment of China, thus forming complex geomorphologic landscapes with plateaus, high mountains and large basins gradually. Erosion cycles and physiographic stages are effective methods and important means for the study of the Cenozoic geological history. Based on discussing some new ideas about erosion cycles and physiographic stages, the Cenozoic physiographic sequences in China are put forward in this paper. The relation between physiographic transition and climatic changes and its response to loess deposits are also discussed.