宽甸黄椅山玄武岩和巨晶的同位素与微量元素地球化学

ISOTOPE AND RARE ELEMENT GEOCHEMISTRY OF THE HUANGYISHAN BASALT, KUANDIAN, LIAONING PROVINCE, CHINA

All of the rare element and isotope characteristics of the Huangyishan basalts are similar to that of the original mantle of the Earth. Since the lava crystallization was too quick to reach the chemical equilibrium between the solid and liquid phases, it is reasonable using the rare element compositions of the megacrysts and the melts to calculate the rare element distribution coefficients of the silicates crystal and melt since there are genesis relations between the megacryst and its host rock basalts. The double-concave shape of REE patterns of the alkali basalt show that the basalt melt had reached equilibrium or quasi-equilibrium with the garnet and clinopyroxene megacrysts. The positive Eu anomaly of the basalts is actually the turning point of the double-curved REE patterns but with no relations with oxygen fugacity of the mantle.