依据孢粉资料探讨我国西北地区第三纪时期的干旱化及其与季风的关系  

PALYNOLOGICAL IMPLICATIONS FOR RELATIONSHIP BETWEEN ARIDIFICATION AND MONSOON CLIMATE IN THE TERTIARY OF NW CHINA

作　　者：宋之琛[1] 王伟铭[1] 毛方园[1] 

机构地区：[1]中国科学院南京地质古生物研究所,南京210008

出　　处：《古生物学报》2008年第3期265-272,共8页Acta Palaeontologica Sinica

基　　金：中国科学院资源环境领域知识创新工程重要方向项目(KZCX2-YW-105);国家重点基础研究发展规划项目(2006CB806400);国家自然科学基金重点项目(40730210)联合资助

摘　　要：文章依据孢粉资料讨论我国西北地区第三纪时期植被的演变情况,认为始新世时古地中海和副古地中海(Paratethys)自南亚及中亚地区的撤退,以及中新世时青藏高原的隆起对东亚季风的屏蔽,都对西北地区的干旱化起了重大作用。上新世中期开始的青藏高原的持续隆起和冬季风(寒流)的劲吹,使本地区植被成分更趋单调,演变成荒漠型植被,气候更趋干旱。根据孢粉资料推测:太平洋季风至少在中中新世已经形成并可伸展至兰州地区,而印度洋季风有可能是同时出现的,并可侵袭到目前的甘肃南部地区。Based on palynological data, we suggest that the retreat of the Tethys and Paratethys from southern and Central Asia in Eocene and the uplift of Qinghai-Xizang Plateau in Miocene have largely shielded the monsoon climate northwestward, and have resulted in the Tertiary aridification in NW China. With the persisting uplift of Qinghai-Xizang Plateau and the strengthening of winter mon-soon （cold snap） in the Pliocene, the climate in these regions tended to become much drier and the component for vegetations was rather barren, which led to the desertification. The current data show that the Pacific monsoon was formed at least in the middle Miocene, and could have reached to the present Lanzhou area, Gansu Province, whereas Indian monsoon might have occurred in the same time, reaching to the southern area of Gansu Province.

关 键 词：干旱化 植被 季风 第三纪 中国西北地区 

分 类 号：Q914[天文地球—古生物学与地层学]