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碱度在火山岩岩石学及地质学上应用较广,意义较大.现列举以下十个方面加以说明. 碱度与火山岩系列及组合的关系1.火山岩的碱度与系列是两个不同的概念,但系列多以碱度来划分,故又有联系.划分火山岩碱度的方法很多,简便而又定量的方法是钙碱指数(CA)及组合指数(σ).火山岩的碱度通常分为两级:钙碱性岩(广义)的CA>56,σ<3.3;碱性岩(广义)的CA<56,σ<3.3.钙碱性岩(广义)又细分为钙性岩(CA>61,σ<1.8)、钙碱性岩(CA=56～61,σ=1.8～3.3);碱性岩可细分为碱钙性岩(CA=51～56)、碱性岩(CA<51,σ>9).碱钙性岩又称碱性岩;碱性岩又称
Alkalinity in the volcanic petrology and geology widely used, of great significance .Considering the following ten aspects to illustrate .Basic and volcanic series and combinations of relationship 1. Volcanic alkalinity and series are two different concepts , But the series are mostly divided by alkalinity, so there is a link between them.Many ways to divide the volcanic rock alkalinity are simple, the quantitative methods are the caustic soda index (CA) and the combination index (σ) Two levels: CA> 56, σ <3.3 for calc-alkaline rocks (generalized) and CA <56, σ <3.3 for alkaline rocks (broad sense) (CA = 56-61, σ = 1.8-3.3). Alkaline rocks can be subdivided into alkali-calcium rocks (CA = 51-56), alkaline rocks <51, σ> 9) Alkali-calcareous rock, also known as alkaline rock; alkaline rock, also known as