关于华北克拉通燕山期岩石圈减薄的机制与过程的讨论_是拆沉_还是热侵蚀和化学交代_.pdf

13 2 ( ( ) ; ) Vol. 13 No. 2 2006 3 Earth Science Frontiers ( China University of Geosciences, Beijing; eking University) Mar. 2006 : , ? 邓晋福, 苏尚国, 刘 翠, 赵国春, 赵兴国, 周 肃, 吴宗絮 11 , 100083 21 , 100083 31 ( ) , 100083 DENG Jin-fu, SU Shang-guo, LIU Cui, ZHAO Guo-chun, ZHAO Xing- guo, ZHOU Su, WU Zong-xu 11 State K ey Laboratory of Geolog ical P rocesses and Mineral Resources, China University of Geosciences, Beij ing 100083, China 21 K ey Labor atory of L ithosp here ectonics and L ithop robing echnology of Ministry of Education, China University of Geosciences, Beij ing 100083, China 31 School of Earth Science and Mineral Resources, China University of Geosciences , Beij ing 100083, China DENG Jin-fu, SU Shang-guo, LIU Cui, et al1 Discussion on the lithospheric thinning of the North China craton: delamination? or thermal erosion and chemical metasomatism? Earth Science Fr ontiers , 006, 13( ) : 105-119 Abstract: There are tw o prevailing models for the lithospheric thinning of the North China craton: ( 1) delami- nation, (2) thermal erosion and chem ical metasomatism1 T o assess them, on the basis of both magmatism and tectonic deformation, w e have considered the following: ( 1) structural elements, orogenic episodes, and the P- -t path of orogenic processes in Yanshan belt; (2) crustal tectonic thickening based on evidence from cont- ractional deformation, igneous rock assemblages and lower crustal xenoliths; and (3) thermal models and mod- els of crust-mantle interaction for igneous petrogenesis1 From these considerations w e discuss reasons for the transformation of buoyant cratonic lithosphere to a denser one, and favor delaminat ion as the model for lithos- pheric t hinning, rat her than thermal erosion and