排序方式: 共有3条查询结果,搜索用时 0 毫秒
1
1.
2.
本文依据攀枝花-西昌裂谷四十几个火成岩的主要元素、过渡金属元素、稀土元素和其他微量元素的分析结果,探讨了这些岩石的成因和岩浆过程。从主要元素成分来看,明显地显示出双众数岩套的特征。过渡金属元素显示了Cr和Ni的强烈亏损与Ti的明显富集,反映了复杂的结晶分离作用历史。所有岩石的稀土元素分配型式都是富集型的,暗示出原始岩浆可能来自原始地幔的低程度部分熔融,玄武岩的亲石岩浆元素丰度经原始地幔值标准化后的分配型式,显示出一种介于碱性玄武岩与大陆拉斑玄武岩之间的图形,这支持了它们的裂谷大地构造环境,也暗示了原始岩浆来自深处的原始地幔区,可能是石榴二辉橄榄岩部分熔融的产物。 相似文献
3.
A lot of granitoid rocks occur in Panxi area, SW China, which were formed during Jinningnian-Chengjiangnian, Hercynian-Indosinian and Yenshanian. According to their trace elements geochemical and petrochemical characteristics, they can be divided into calc-alkaline and alkaline granites. The petrogenesis and magma sources of these granitoid rocks are different. The Jinningnian-Chengjiangnian granitoid rocks include Mopanshan granite body, Moshaying granite body and Lugu granite body. The Mopanshan body might be formed by partial melting of the lower crust and due to refusion of basic volcanic rocks. The magma source of the Moshaying and the Lugu bodies might be formed by partial melting of the upper crust. The Hongge-Ailanghe granites belonging to the Hercynian-Indosinian may be products of complex melting from the crust-mantle materials caused by the increase of temperature during rifting stage in the area. The Cida and Taihe alkaline granites belonging to the Hercynian-Indosinian might be derived from 相似文献
1