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用预浓集中子活化法测定了中祁连岩带清水沟地区方辉橄榄岩中稀土元素(REE)的含量,并用仪器中子活化法测定了玄武岩中的REE。依据测定结果分析了方辉橄榄岩和玄武岩的地球化学特征:方辉橄榄岩为上地幔经历了部分熔融后残留的地幔物质;拉斑玄武岩很可能是由伏于消减带之上的富轻稀土的上地幔楔部分熔融形成的。所以中祁连清水沟蛇绿岩属岛弧火山活动的产物,可能形成于弧前或者弧后的构造环境。
The content of rare earth element (REE) in the galea peridotite in Qingshuigou area of the Central Qilian rock zone was determined by the preconcentration neutron activation method, and the REE in basalt was measured by neutron activation. Based on the results, the geochemical characteristics of the harzburgites and basalts are analyzed: Hatchlite is a mantle material that has undergone partial melting after the upper mantle; and that the tholeiite basalts are likely to be enriched by light-rich rare earths Of the upper mantle wedge partially melted. Therefore, the Qingshuitang ophiolite in Qilian is a product of the island arc volcanism and may form in the tectonic environment before or after the arc.