摘要
本文通过对华北的大兴安岭—燕山地区晚中生代火山-深成岩岩石化学、同位素地质学的分析,认为该地区岩浆的形成和演化与板内伸展环境下的底侵作用有关,而与太平洋板块俯冲无直接的成因联系。本文展示了较高分辨率的日本海沟—长白山—蒙古额尔德尼查干的地震层析图象,揭示了太平洋俯冲板片的形态特征;再结合对俯冲时间及俯冲作用与岩浆作用时差的研究,进一步证明板块俯冲与研究区的岩浆活动无直接关系。最后通过底侵作用年代学的研究,将大兴安岭—燕山中生代岩浆活动与层析图象显示的大陆板内软流圈上涌体联系起来。
Petrochemistry and isotope geology of the Late Mesozoic volcanic-plutonic rocks from the Da Hinggan Mts. and the Yanshan Mts. in north China are studied. The results indicate that the formation and evolution of magmas in this area are related to intraplate magmatic activities under an extensional environment but not directly related to the subduction of Pacific Plate. In this ppaper, high resolution tomographic images across Japanese Trench-Changbai Mts. -Erden Cagaan of Mongolia are displayed, delineating the shape of the subducted Pacific slab, which in combination with the subduction time and time-lag between the subduction and magmatism, further proves the independence of the magmatic activities from the plate subduction. Finally, chronological research of underplating connects the Mesozoic magmatic activities in the Da Hinggan Mts. -Yanshan Mts. with the upwelling of the sub-continental asthenosphere displayed by the tomograghic images.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2001年第1期56-63,共8页
Acta Geologica Sinica
基金
国家自然科学基金资助项目(编号496772156
49872079)
国家高技术研究发展计划资助项目(编号863-820-01-04)的成果。
