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对近年来华北克拉通不同时代地幔橄榄岩捕虏体和捕虏晶的研究结果进行了系统的归纳和总结,旨在为华北克拉通破坏过程的进一步研究提供新的思路.Re-Os同位素研究结果证明华北岩石圈减薄前岩石圈地幔的确形成于太古代.这种密度低、难熔程度高的古老岩石圈地幔能够被破坏和减薄的关键是由橄榄岩与多来源熔体的相互作用造成岩石圈地幔的组成和物理性质的改变引起的.华北克拉通周边板块的俯冲-碰撞作用不仅提供了克拉通破坏的动力来源,而且俯冲下去的大陆壳或大洋壳物质熔融还为岩石圈地幔组成的改变提供了源源不断的熔体.120Ma左右的区域性热异常的存在导致已经被改造的岩石圈地幔熔融,此时或随后岩石圈的伸展作用以及软流圈上涌进一步加剧了地幔的熔融和岩石圈的减薄.因此,华北岩石圈的破坏和减薄是橄榄岩-熔体相互作用(加挥发分)、区域热异常的升高(增温)和岩石圈伸展(减压)联合作用的结果.这一复杂的地质过程最终形成了华北中生代、新生代高度化学不均一的“混合”岩石圈地幔,并导致了不同地区不同时代地幔橄榄岩捕虏体组成的巨大差异.
The research results of xenoliths and xenocrysts of mantle peridotites of different ages in North China Craton are systematically summarized and summarized in order to provide new ideas for further research on the destruction process of craton in North China .Re-Os isotope studies The results show that the lithospheric mantle did form in the Archean before the thinning of the North China lithosphere.The key to the destruction and thinning of the ancient lithospheric mantle beneath the low density and high degree of refractivity is the interaction between the peridotite and the multi-source melt The subduction-collision effect of the plate around the North China Craton not only provided the source of the cratonic damage, but also the melting of the subducted continental crust or oceanic crust and the lithosphere The change of mantle composition provided a steady flow of melt.The presence of regional thermal anomalies around 120 Ma resulted in the melting of the lithosphere mantle that had been reformed, and at this time or later the extension of lithosphere and upwelling of asthenosphere further aggravated the mantle Of the melting and lithospheric thinning.Therefore, the destruction and thinning of the North China lithosphere is the peridotite - melt interaction (plus volatile) As a result of a combination of regional thermal anomalies (warming) and lithospheric extension (depressurization), this complex geological process eventually resulted in Mesozoic and Cenozoic highly heterogeneous “mixed” lithospheric mantle , And led to a huge difference in the composition of the magma peridotite xenoliths in different regions in different times.