地幔不均一性与地幔循环的多维表征和原因思考OA北大核心CSTPCD

The mantle experienced core-mantle-crust differentiation in its early stages,followed by convection circulation at various scales,resulting in mantle heterogeneity.Overthe past three decades,the study of oceanic basalt has gradually established a comprehensive geochemical system of the mantle,revealing the presence of various mantle end members and non-radioactive isotopic evidence,confirmingthe existence of mantle heterogeneity.However,the relationship between mantle heterogeneity and mantle cycling in terms of time and space scales remains unclear,as well as the evolutionary history and laws governing mantle heterogeneity.Geophysical studies have provided evidence for the spatial heterogeneity of the traversal convective system through observations of differences in thickness of the upper mantle lithosphere between the ocean and the continent,velocity anomalies in the middle and lower mantle,and the morphology of subduction plates.The combination of geochemical and geophysical methods is crucial for studying mantle heterogeneity,and it has been widely accepted to use this"binocular"approach to better understand the composition and structure of the mantle.This paper considers the internal logic of the superficial supercontinent cycle and mantle heterogeneity by integrating different manifestations of the geochemical field and geophysics,and contrasting oceanic and continental patterns in both present and historical periods.The significance of mantle heterogeneity in the context of global evolution is emphasized,and the potential for establishing amantle cycle driving model through multiple approaches is proposed.