摘要
达拉布特蛇绿岩带的镁铁质岩属亚碱性和碱性系列，可能是弧后盆地火山活动的产物。根据镁铁质岩的层位关系、岩浆来源和微量元素特征，可将该盆地的地质演化概括为扩张阶段和封闭阶段。盆地扩张阶段早、中期喷发的镁铁质岩具有低的稀土和不相容元素丰度，而在盆地封闭阶段晚期喷发的碱性玄武岩，其特点是稀土和大多数不相容元素丰度极大增高，其稀土元素分布模式为轻稀土元素强烈富集型。
A detailed geochemical study has been carried out on mafic roc ks from the Dalabute ophiolite. Based on their petrochemistry, the studied rocks can be divided into subalkalic and alkalic series. Their geochemical characteri stics of trace elements and Nd and Sr isotopes show that these mafic rocks erupt ed in a back-arc basin. The mafic rocks at the early and middle stages of expa nsion of the basin are low in abundance of REE and other incompatible elements, while alkalic basalts erupted at later stages of closing of the basin are enrich ed in light REEs and other incompatible elements.
出处
《矿物学报》
CAS
CSCD
北大核心
2000年第4期363-370,共8页
Acta Mineralogica Sinica
基金
国家攀登计划预选(95-预-39)
国家杰出青年基金(批准号:49625304)
