Abstract
Synopsis: The petrographical setting of pyroxene and mica-group minerals in the Tertiary alkali granite of Ailsa Craig is described. Electron microprobe analyses of pyroxenes ranging from He 87 Ac 13 to He 0 Ac 100 are given and their variable contents of minor elements (Al, Ti and Zr) shown to compare closely with a similar occurrence recently described from a South Greenland nepheline-syenite. Glauconitic minerals occur in patches of interstitial crystallisation in the granite.

This publication has 5 references indexed in Scilit: