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nephelinite n.【地質學;地理學】霞巖。

nephelite

On the basis of the study on the petrology , trace element , and isotopic geochemistry , the primary magma of volcanic rocks can be divided into two series according to their originated rocks and degree of partial melting . one is the basanite - alkaline basalt - olivine tholeiite magma series , which are generated by partial melting from spinel iherzolite ; the other is nephelinite magma - alkaline picritic basalt magma , which are generated by partial melting of the garnet iherzolite 巖石化學、微量元素、同位素地球化學證據都表明,華北、華南地區的火山巖根據源巖和局部熔融程度的不同,可以分為兩個原生巖漿系列:一個是源巖為尖晶石二輝橄欖巖,隨著局部熔融程度的增加,形成的碧玄巖巖漿-堿性玄武巖巖漿-橄欖拉斑玄武巖巖漿;另一個是源巖為石榴石二輝橄欖巖,隨著局部熔融程度的增加形成的霞石巖巖漿-堿性苦橄玄武巖系列。