岩浆岩综合碱度指数(CAI)的计算方法和意义  

Comprehensive Alkalinity Index (CAI) of Magmatite: Calculating Method and Its Significance

作　　者：邹海波[1] 徐洪武[1] 周新民[1] 

机构地区：[1]南京大学地球科学系

出　　处：《地质与勘探》1990年第10期21-27,共7页Geology and Exploration

摘　　要：根据酸碱电子理论、软硬酸碱理论,可以得到岩浆岩综合碱度指数(CAI)的计算公式,即CAI=0.98×X_(TiO_2)+3.62×X_(Al_2O_3+2.95×X_(Fe_2O_3)+6.54×X_FeO+4.96×X_MnO+7.11×X_MgO+8.32×X_CaO+12.07×X_(Na_2O)+13.05×X_(K_2O),其中X是摩尔分数.CAI值可以更准确地反映岩浆岩的碱性程度,据CAI划分岩浆岩的类型具有许多优点.Based upon electronic theory of acid and base and in combination with theory of acids and bases (including hard and soft ones), the authors have derived a formula for calculating the comprehensivealkalinity index of magmatic rocks as following:CAI=0.98×X_TIO_2+3.62×X_Al_2O_3+2.95×X_Fe_2O_3+6.54×X_FaO++4.96×X_Mro+7.11×X_MgO+8.32×X_CaO+12.07×X_Na_2O++13.05×XK_2O (where X is the molar fraction),The alkalinity of a magmatic rock can be more accurately expressed by the value of CAI.

关 键 词：岩浆岩 综合碱度 指数 计算 

分 类 号：P588.112[天文地球—岩石学]