北京平原地区新生代古地理概貌

燕山运动造成了本区基底构造的基本轮廓—北东向雁列式隆起与拗陷。老第三纪至新第三纪为内陆湖盆扩大时期,早更新世初期出现北京海湾,其后逐步发展为今天地理上的“北京湾”。本文概略地描述了这一古地理演化过程及同生断裂的发育与北京平原地区古地理演化的关系,并指出研究全新世以来古地理演化趋势的重要意义。

A SKETCH ON STUDY OF CENOZOIC PALEOGEOGRAPHY IN BEIJING PLAIN

The fundamental framework of geological structure of bedrock in Beijing plain was created due to Yanshan Movement in this region. There were mainly uplifts and downwarpings with arrangement in an echelon type. During Eogene there were developed some innercontinental narrow basins along some contemporaneous faults. And up to Neogene it was the stage of wide spreading of these fresh water basins. Then, in the beginning of Early Pleistocene Epoch, Beijing gulf was appeared when the ingression of sea water had happened. Afterwards it was developed step by step to become to modern form-what is called "Beijing Bay" in the sense of geography. It is a dry delta standing in front of mountainous district of Beijing. Some features of contemporaneous faults and their activities on C3nozoic paleogeographic evolution in Beijing plain are roughly described as well in this paper. And the studying of developing tendency of geographical environment is of great significance, ever since the time of Holocence Epoch, it was also mentioned in this paper.