Cumulate complex xenoliths in the early Mesozoic in eastern Inner mongolia

Mafic xenoliths occur in Mesozoic diorites from nine localities in eastern Inner Mongolia from the Da Hinggan Mts, to Huabei craton, Their petrologic and geochemical features suggest that they are an intact suite of cumulate complex whose mineral assemblages contain typical patent mantle metasomatis m minerals such as pargosite, phlogopite and apatite, Their REEs and trace element characteristics suggest a comagmatic relationship in these cumulate s with different compositions. Isotopic dating of the xenoliths indicates t hat they are products of the mantle magmatic underplating in the Early Meso zoic (237-224 Ma), and they may provide direct evidence for the crust-mantl e interaction and vertical accretion of continental crust under a backgroun d of the mantle upwelling in the Early Mesozoic in Huabei region.