摘要
临沧花岗岩基中段花岗闪长岩类属残留岩基 ,岩石学特征与临沧花岗岩基其它花岗岩明显不同。地球化学特征与二长花岗岩类相近 ,两类花岗岩之稀土特征与大勐龙岩群(Pt2 d .)基本一致。加之花岗闪长岩类中含镁铁质微粒包体 (MME) ,认为花岗闪长岩类存在岩浆混合作用 ,岩浆向上运移过程中未发生同化混染和分离结晶作用。结合同位素测年结果及其它地质事件 ,确定是在二叠纪侵位于活动陆缘 ,是区内古特提斯洋向东俯冲消减作用的产物。
The granodiorite in the middle part of Lincang granite batholith belonges to a relict batholith with different petrographic characteristics from the granitr of Lincang granite batholith.The geochemical characteris tics are similar to those of adamellite.And REE characteristics of two types of traite are basically same as those of the Damenglong Rock Group (Pt 2d).The mafic microgranular inclusion(MME)in the granodiorite shows the magmatic mixing process,whithout assimilation-contamination and fractional crystallization in the upward movement of magma.According to the isotopic dating,it was emplaced into the active continental margin in Permian,which was resulted from the eastward subduction of the Tethys sea.
出处
《云南地质》
2003年第4期426-442,共17页
Yunnan Geology
基金
中国地质调查局
1:2 5万临沧县幅区域地质调查
