喇嘛苏铜矿中酸性岩体岩石学特征

采用费氏台五轴定位法和D C Noble等提出的求斜长石成分和有序度方法、鉴定图表,在喇嘛苏矿区三种中酸性岩体的岩石薄片中选择比较新鲜的、自形程度较好的斜长石,测得斜长石牌号χ(An)=24～56,有序度S=0.4～0.7,说明斜长石以中长石为主,属中温型,即在结晶过程中岩浆冷却的速度较快;斜长石环带有正常环带,也有韵律环带,表明在结晶过程中总体是正常结晶环境,而期间有上下反复运动和岩浆房内压力的反复变化。

Petrologic characteristics of the acid-intermediate intrusive bodies in Lamasu copper deposit

Fishercher stokes five axis positioning method, plagioclase identification plot, the method for calculation of composition and order of plagioclase put forward by D.C. Noble to identify plagioclase in three kinds of acid-intermediate intrusive bodies in Lamasu copper deposit. Samples are relatively fresh with highly euhedral crystal of plagioclase in thin section. The identification is that An% of its plagioclase mostly is between 24 to 56 and degree of order S=0.4 to 0.7 that means the domination of andesine formed under condition of medium temperature, i.e. magma is cooled quickly during crystallization of the plagioclase. Normal and rhythmic girdle in the plagioclase shows that it is crystallized under normal condition with crystal ocillation during its crystallization process, the crystallographic environment generally is normal, and there has up and down movement and the pressure change in Magma chamber again and again occasionally.