Petrology, geochemistry and petrogenesis of Early Mesozoic diorites in Harqin area, Inner-Mongolia
内蒙古喀喇沁早中生代闪长岩的岩石学,地球化学及其成因

Isotopic geochronology, petrology and geochemistry of diorites containing mafic-ultramafic cumulate and basic granulite xenoliths from Harqin area of Inner-Mongolia have been studied. The results suggest that (1) K-Ar datings of whole rock and single mineral of diorites give ages of 218～223 Ma; (2) diorites have no genetic correlation with cumulate and granulite xenoliths; (3) these diorites in different lithologies are probably products of highly partial melting of Archean amphibolite; (4) the Early Mesozoic underplating lead to the formation of diorites, reflecting an extensional tectonic setting.