Isotopically-enriched Components in Evolution of Late Cenozoic Potassic Magmatism in the Heilongjiang Province, NE China
Four groups of high-K volcanic rocks with different variations of SiO2, K2O, and Mg-numbers have been defined in Late Cenozoic volcanic fields of the Heilongjiang province. Essential trace-element difference has been found between the groups with 87Sr/86Sr ratios above and below 0,7052. It is suggested that this value is characteristic of a common component from the asthenospheric domain, which has originated due to Mesozoic through Cenozoic erosion of the isotopically enriched lithosphere in East Asia. On basis of geochemical data on the volcanic rocks studied, the Late Cenozoic rift-related lithospheric erosion is described.