CIPW标准矿物计算法应用时存在问题的探讨

DISCUSSION ON SOME PROBLEMS ABOUT CIPW METHOD IN APPLICATION

CIPW法是当今最广泛应用的岩石化学计算法之一 ,其目的在于提供模拟矿物成分和相对数量 ,为岩石正确命名提供依据 .作者在应用CIPW法过程中 ,发现不同教科书上的计算原理及方法存在差异 ,给实际应用造成不便 ;本文就斜长石牌号的计算方法、CIPW计算原理以及钠长石分配方法等问题进行了探讨 .

CIPW is one of the most extensively used petrochemistry calculating methods. Its purpose is to provide a basis for rock naming by simulating mineral components and relative amounts. The author found that the calculating principles and methods in different textbooks are various, that is unconvenient in practical application. After discussing the calculating method of plagioclase serial number, CIPW calculating principle and albite distributing way, the author concluds that:1) as calculating the plagioclase serial number,the amount of albite should adopt two times of albite molecular number; 2)when MgO′+FeO″>SiO 2′>0.5(MgO′+FeO″),we should use the following hypotheses:Hy+Ol=SiO 2′,and Hy+2Ol=MgO′+FeO″;and 3)Rittmann method is suggested to name rocks, as it is more reasonable and accurate.