中国地球化学学报(英文版)2001，Vol.20Issue(1)：59-72,14.
Age, Mechanism and Direction of East Qinling-Dabieshan Lithosphere Delamination Petrological Evidence and Stipulation
Age, Mechanism and Direction of East Qinling-Dabieshan Lithosphere Delamination Petrological Evidence and Stipulation
李超 1陈衍景 1何顺东2
作者信息
- 1. Department of Geology, Peking University, Beijing 100871, China
- 2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
- 折叠
摘要
Abstract
Through studies of P-T-t paths and decompressive retrograde metamorphic textures of metamorphic rocks in the East Qinling-Dabieshan region, the authors determined the Mesozoic crust rapid uplifting age, and then inferred that in the East Qinling-Dabieshan region lithosphere delamination occurred from T3 to J1. The Yanshanian granites produced by delamination are developed well in the East Qinling-Dabieshan region. But due to the Gondwana plate effect, magmatism in the region caused by delamination lagged until J3 when the northern Tibet terrane and the Eurasian plate completely amalgamated. Additionally, due to western Pacific plate subducting underneath the Eurasian plate, in the East Qinling-Dabieshan region the stress state was transformed from compression to extension. So in the region from J3 to K2 magmatism was most intensive, and liberalization was also relatively strong. Geophysical data reflect that in the East Qinling-Dabieshan region the asthenosphere rose to the shallow level, the Moho is flat with no mountain root, and the crustal thickness is less than 40 km on average.These features agree with those of collisional orogenes in which delamination has occurred.Through contrasting differences in surface and interior depth between east and west Qinling we believe that delamination proceeded from east to west.关键词
East Qinling-Dabieshan Mountains/delamination/granite/Mesozoic/P-T-t pathKey words
East Qinling-Dabieshan Mountains/delamination/granite/Mesozoic/P-T-t path分类
天文与地球科学引用本文复制引用
李超,陈衍景,何顺东..Age, Mechanism and Direction of East Qinling-Dabieshan Lithosphere Delamination Petrological Evidence and Stipulation [J].中国地球化学学报(英文版),2001,20(1):59-72,14.
