Formation, destruction and deformation of the Mesozoic crust-mantle transition zone in west Liaoning province, China.

利用火成岩及其携带的捕虏体的岩石学、年代学等研究成果,反演辽西中生代时期的壳幔相互作用,重塑这时期的壳幔边界组成。对应于中生代活跃的壳幔相互作用,辽西义县-北票一带理论上应该存在一个发育的壳幔过渡带。然而现今的各种地球物理研究显示辽西的莫霍面是清晰的间断面,其上、下地震波速变化从6.5～6.7km/s 截然变成8.0～8.1 km/s。壳幔过渡带到那里去了?围绕这一问题,本文依据火山岩及其捕虏晶的研究,探讨了在软流圈底辟体上涌背景下,壳幔过渡带被破坏和改造的原因。最后从演化角度将辽西与张家口和西藏高原的壳-幔边界进行了比较。The Mesozoic crust-mantle interaction in west Liaoning province is studied according to petrologic and chronologic results of igneous rocks and xenoliths in them, and composition of the crust-mantle boundary in Mesozoic is reconstructed. Theoretically, there should be a developed crust-mantle transitional zone in Yixian-Beipiao area of west Liaoning province, where occurred active Mesozoic crust-mantle interaction. But the current Moho in the west Liaoning province is a clearly discontinuous interface with the seismic velocities above and below it being 6.5 similar to 6.7 km/s and 8.0 similar to 8.1 km/s respectively. Where the crust-mantle transitional zone could have gone? To answer this question, the authors explore the possible causes and processes of deformation and destruction of the crust-mantle transitional zone in the light of upwelling diapirs of asthenosphere. The crust-mantle-boundary structure in the west Liaoning province is also compared evolutionally with those in the Zhangjiakou area and in the Tibet plateau.SCI(E)中文核心期刊要目总览(PKU)中国科技核心期刊(ISTIC)中国科学引文数据库(CSCD)0122825-28322