渭河宝鸡段河谷地貌的构造气候响应

TECTONIC CLIMATE RESPONSE IN THE GEOMORPHOLOGY OF THE WEIHE RIVER VALLEY AROUND BAOJI,SHAANXI PROVINCE

渭河宝鸡段发育五级河流阶地，分别形成于１．２ＭａＢＰ、０．８ＭａＢＰ、０．５ＭａＢＰ、０．１３ＭａＢＰ、０．００９ＭａＢＰ。它们是第四纪早更新世中期以来，青藏高原整体隆升过程中几个大幅度抬升阶段及其驱动的气候变化的响应，记录了准０．４Ｍａ、准０．１Ｍａ周期的构造气候旋回与亚旋回。这种尺度的构造气候旋回与黄土—古土壤序列记录的天文气候旋回很吻合，表明它们在成因机制上的某种内在联系，深刻认识这一点，将有助于全面理解区域环境演化的规律性与差异性。文中还初步探讨了渭河贯通陇山的时代和统一水系的形成问题。

There have been developed five stages of terraces,formed in 1.2MaBP,0.8MaBP,0 5MaBP,0 13MaBP,0 009MaBP,respectively,in the Weihe river around Baoji,Shaaxi Province.Each of these stages is considered to be the response to the corresponding large up lifting and consequent climatic changes during the rising of Qingzang Plateau's since middle period of early Pleistocene,witnessing tectonic climatic cycles and sub cycles of a period of about 0 4Ma and 0 1Ma.Such scale tectonic climatic cycles well agrees with the astroclimatic circles recorded by loess paleosol sequence.This shows that there may be some causative relation between them. A knowledge of the relation will be helpful to the undertanding of the environmental evolution of the region.A preliminary discussion on the age of the passage of the Weihe river through the Longshan Mt.and the formation of a unified drainage system of it.