碱性火成岩
碱性火成岩-
霞石主要生成于富含Na2O而贫SiO2的碱性火成岩及伟晶岩中，晶体呈六方短柱状、厚板状等粒状集合体或致密块状。
Nepheline forms mainly in the alkaline igneous rocks and pegmatites , which contain more Na 2O and less SiO 2 . Its texture is mainly shaped like hexagonal columniation , thick slate , granule or compact mass .
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塔里木盆地南北缘几个地方的新生代火山岩类具有贫硅富碱、特别是富钾的特点，均属于碱性火成岩系列。
Most of the Cenozoic volcanic rocks from the south and north rims of Tarim basin are classified as alkali series .