云南个旧拉丁尼克期玄武岩地球化学特征及其大地构造背景

Geochemistrical Features and Tectonic Settings of Ladinian Basalts in Gejiu,Yunnan Province

个旧地区拉丁尼克期火山岩的地质、地球化学特征研究表明:该期玄武岩的岩石类型为杏仁状斑状纤闪石化玄武岩,属于硅不饱和、富碱、高钛,镁、铁偏高,铝偏低,具有大陆碱性橄榄玄武岩的组分特征。该玄武岩为陆内拉张环境下基性程度高、分异程度低的幔源岩浆分异的产物,形成于大陆板内裂谷环境,并与拉裂作用有关。

Study on geology, geochemistry of the Ladinian basalts in Gejiu, Yunnan Province cates that these basalts are of blastoamygdaloidal structure and belong to olivineous alkali-basalts and they are of features of unsaturated silicon, of abundant alkali, magnesium and iron and of excessive titanium and low aluminium. The basalts came from high basic magmas of mantle derivation and were formed by low degree of differentiation under a general extension setting in a rift.