华北下地壳岩石组成-物性综合及其精细结构研究

Many important progresses, such as on the discovery of the spatial structural differences of the deep-lithosphere, the decision of the subcontinental lithospheric mantle (SCLM) through times beneath the North China Craton, and so on, had been achieved by the Earth scientists, who were supported by the “Destruction of the North China Craton” Grand Research Plan under the NSFC in the passed four years. However, deficiently geological and geophysical studies of the lower crust beneath the North China Craton (NCC) apparently bounds our comprehensive understanding of the NCC destruction and possible more important achievements in Earth sciences. This is because that the continental lower crust (and crust-mantle transitional zone) is not only an important magmatism and metamorphism region, but also is one of the important geochemical and geophysical boundaries of the Earth. And also that the complex forming processes and non-accessible detection of the lower crust obscured its chemical composition and geological and geophysical status. Medium- and high-grade metamorphic rocks, such as the deep-seated xenoliths in volcanoes and the outcrops as terranes, are the directly sampled lower crust, however, the thoroughly mapping of the lithospheric structure and composition is needed that the combination of physical properties of the lower crustal samples and the regional geophysical detection. .Our research will focus on the chemical and physical properties, the coming depths and the formation ages of the lower crustal samples collected from the spatial and temporal volcanoes and the massifs surrounding those volcanoes in the North China Craton. Multi-integration study of the lower crustal rocks in petrologic, physical and chemical properties and reported datasets of regional geophysical detection, refine the composition, structure and evolution of the lower crust beneath the craton. These thus will greatly improve our understanding the processes of the continental formation and evolution.

重大计划实施以来在壳-幔空间结构差异发现、不同时代地幔属性厘定等方面取得了重要进展。但缺乏针对华北克拉通重点地区下地壳综合地质-地球物理研究，制约人们对克拉通破坏过程的完整认识及可能的重大成果产生。这是由于下地壳(及壳-幔过渡带)既是岩浆、变质等作用的重要发生区, 也是地球化学、地球物理学性质变异的重要界面；加之下地壳形成过程复杂和不易直接探测的原因, 其物质组成及状态仍不清楚。中高级变质岩石是研究深部地壳的直接样品，但完整的岩石圈组成结构认识，须结合配套样品的物理性质分析及研究区已有地球物理探测成果实现多维研究。项目拟对华北不同时代位置火山岩下地壳捕虏体及火山岩周边地质体岩石，进行捕虏体化学-物理性质、来源深度和形成年龄的研究。通过配套样品的岩石物性与岩石矿物及化学组成综合分析研究,利用人工地球物理探测成果，获取华北下地壳的精细结构和形成演化过程认识，提升对大陆形成与演化过程的认知水平.

重大计划实施以来在诸多方面取得了重要进展，但缺乏针对华北克拉通重点地区下地壳综合地质-地球物理研究，制约人们对克拉通破坏过程的完整认识。这是由于下地壳(及壳-幔过渡带)既是岩浆、变质等作用的重要发生区, 也是地球化学、地球物理学性质变异的重要界面；加之下地壳形成过程复杂和不易直接探测的原因, 其物质组成及状态仍不清楚。中高级变质岩石是研究深部地壳的直接样品，但完整的岩石圈组成结构认识，须结合配套样品的物理性质分析及研究区已有地球物理探测成果实现多维研究。项目对华北不同时代位置火山岩下地壳捕虏体及火山岩周边地质体岩石，进行了捕虏体化学-物理性质、来源深度和形成年龄的研究。.通过配套样品的岩石物性与岩石矿物及化学组成综合分析研究,利用人工地球物理探测成果，获取华北下地壳的精细结构和形成演化过程认识，具体包括：1) 恢复了华北下地壳岩性结构、年龄结构和磁性下地壳结构，并通过地质结构与物性结构的综合，探讨了不同尺度大陆下地壳磁性演化及其与深部过程之间关系；2）从深部地壳角度发现了华北地块南、北缘所存在的多期古元古代构造热事件和弱的新元古代热活动；3）发现岩石圈初始厚度决定着大陆的命运，陆内显生宙伸展背景下埃达克质岩石属克拉通下地壳部分熔融产物，克拉通破坏过程是壳-幔结构从耦合到不耦合的过程，这些成果提升对大陆形成与演化过程的认知水平。.发表标注项目编号91214204资助的论著35篇（章），其中国际SCI论文31篇、英文专著1章。在31篇国际SCI论文中，90%以上发表在包括Earth Planet Sci Lett, Joural of Petrology, Tectonics, Contrib. Mineral. Petrol., Geophysical Journal International，Journal of Geophysical Research，Precambrian Reesarch, Lithos等在内的地学Top期刊上。依托项目培养的博士、硕士研究生近20名，本科生近30名，其中有5位研究生获得国家奖学金，毕业研究生中，有5人获得湖北省优秀博士或硕士论文奖。1人入选国家百千万人才工程并获国家有突出贡献中青年专家称号。