华北岩石圈减薄的时空不均一特征

华北岩石圈减薄的时空不均一特征

徐义刚

中国科学院广州地球化学研究所广州 510640

收稿日期:2004-09-20 修回日期:2004-09-20 出版日期:2004-09-20 发布日期:2004-09-20

Lithospheric Thinning Beneath North China:A Temporal and Spatial Perspective

Xu Yi-gang

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China

Received:2004-09-20 Revised:2004-09-20 Online:2004-09-20 Published:2004-09-20

摘要/Abstract

摘要： 总结了华北中生代基性岩浆活动的年代学资料和中一新生代岩浆的地球化学特征，认为岩浆随时问的演化趋势与岩石圈减薄过程密切相关。根据富集岩石圈地幔来源的岩浆作用持续时间(180～90Ma)认为该区岩石圈减薄时限约为100Ma。这暗示热机械侵蚀可能是华北岩石圈减薄的主要机制。华北东、西部新生代玄武岩岩浆具有相反的演化趋势，显示了该地区岩石圈减薄作用的时空不均一性。

Abstract: This paper reviews geochronological and geochemical data on Mesozoic -Cenozoic magmatism in North China.It is suggested that the temporal variation in geochemistry of Mesozoic-Cenozoic mafic rocks is coupled with lithospheric thinning process in this region. Consequently,the duration of magmatism(180～90 Ma)provides a first-order estimation for the timescale of lithospheric thinning in this region.The relatively long timescale(～100 Ma)suggests that thermomechanical erosion by convective mantle is the main mechanism of lithospheric thinning. Contrasting magmatic evolution trends in western and eastern North China craton suggest that lithospheric thining may have proceeded in diachronous manner.

徐义刚. 华北岩石圈减薄的时空不均一特征[J]. J4.

Xu Yi-gang. Lithospheric Thinning Beneath North China:A Temporal and Spatial Perspective[J]. J4.