中国东部中、新生代岩石圈转型与减薄研究若干问题

Major transformation of subcontinental lithosphere beneath eastern China in the Cenozoic-Mesozoic:review and prospect.

文中对中国大陆岩石圈的持续热点研究领域?东部中、新生代岩石圈巨厚减薄所涉及的问题进行了简要评述,特别是对减薄问题的提出和认识的历史过程作了较详细的回顾。笔者特别强调了中生代华北岩石圈地幔高度化学不均一性所反映的减薄作用时空分布特征,以及中生代岩石圈地幔的两次转型所导致的高度化学不均一性,进而建议以岩石圈全面转型来描述这一大尺度地球动力学过程。在此基础上讨论了减薄过程的可能机制,认为虽然在局部地区有可能存在拆沉作用,但从全局来看目前更多的岩石地球化学证据与热减薄-化学减薄的假说相兼容。而反映地球深部圈层相互作用的中生代全球事件则被解释为中国东部岩石圈地幔全面转型的动力学背景。显然,对此问题的深化仍将构成本世纪我国固体地球科学一个重要研究领域。

The thinning of subcontinental lithosphere beneath eastern China in the Cenozoic-Mesozoic has been a hot debatable issue in the geological community. This paper presents an overview on topics related to this field, such as the history of recognition of this geodynamic phenomenon, the major transformation of the lithosphere in the Phanerozoic, the mechanism and processes involved, as well as the dynamic regime in tectonics. The author suggests to use the term of transformation, instead of the term of thinning, to describe this event. Meanwhile, the global link between the Mesozoic overturn and what happened in eastern China is emphasized, which opens a variety of approaches for further study.