岩石圈地幔富集改造过程中的壳幔相互作用：鲁西中生代镁铁质岩的地球化学制约

The southeastern edge of the North China Block (NCB) is close to the Dabie-Sulu orogenic belt that was formed by the Triassic continental collision between the South China Block (SCB) and the NCB. There are widespread Mesozoic igneous rocks in this region. Studying the nature of their magma source and geodynamic setting can provide insights into the complex crust-mantle interaction above the continental subduction zone, and have important bearing on the recycling of subducted continental crustal materials with respect to the evolution of subcontinental lithospheric mantle (SCLM). The previous studies are mainly conducted on the whole-rock major-trace elements and radiogenic Sr-Nd-Pb isotopes, whole-rock and mineral O isotopes as well as zircon Lu-Hf isotopes. The results are used to constrain their petrogenesis, and to explore the crust-mantle interaction above the continental subduction zone and its modification on the overlying SCLM. This project focuses on in situ major-trace elements and stable isotopes analysis for minerals from the mafic rocks in Jinan and zouping at Luxi areas. Together with the previous mineral chemistry and whole-rock major and trace elements and isotopic compositions of the mafic rocks, we further constrain the characteristic and origin of the recycled continental crustal materials during the modification of the lithospheric mantle. Our results also can restrict the mechanism of the interaction of the subcontinental lithospheric mantle with the crustal components derived from the deep subduction continental crust in the continental subduction channel.

华北陆块东南缘紧邻三叠纪由华南陆块与华北陆块俯冲/碰撞形成的大别-苏鲁造山带，其中广泛分布的中生代岩浆岩能够提供大陆俯冲带丰富而复杂的壳幔相互作用信息，对于认识深俯冲陆壳物质再循环和大陆岩石圈地幔演化具有十分重要的意义。前人的研究主要基于全岩主微量元素和放射成因Sr-Nd-Pb同位素以及锆石Lu-Hf同位素地球化学特征对其源区进行制约。本研究拟对鲁西地区济南和邹平的中生代镁铁质侵入岩的组成矿物开展电子探针和微区原位的主微量元素含量和稳定同位素组成以及水含量分析。结合已知的地球化学资料，进一步限定地幔源区富集改造过程中再循环的大陆地壳物质的性质和来源，进而能够制约大陆俯冲隧道中深俯冲大陆地壳物质与上覆岩石圈地幔相互作用的具体方式。