Mineral chemistry of peridotite xenoliths in Yangyuan Cenozoic basalts: Significance for lithospheric mantle evolution beneath the North China Craton

The compositions of the minerals and peridotites, especially trace elements of clinopyroxene (Cpx) can well reflect the characteristics of the subcontinental lithospheric mantle (SCLM). Based on the petrographical study of peridotite xenoliths in Yangyuan Cenozoic basalts and chemical study of minerals, the paper mainly analyzes the LAM-ICP-MS trace element compositions of Cpx from the Yangyuan peridotitic xenoliths and discusses the nature and evolution of the Cenozoic SCLM beneath the center of the Trans-North China orogen. The SCLM beneath the Yangyuan area is heterogeneous, forming from the different partial melting of the primitive mantle: most melted less than 5% of the total, except a few among 15%-20%. The coexistence of the fertile and refractory-transitional mantle was better explained by the effects of heterogeneous erosion, transformation and replacement of asthenospheric materials on the cratonic lithosphere mantle.