From Dolerite to Diorite: Older Granite Activity near Ellon, Aberdeenshire

Abstract

Hornblende-schists, probably intruded as dolerite sills, have been permeated by trondhjemitic material. Conversion to rocks of dioritic aspect is the end-stage of this process, but the intermediate stages are more common. The conversion has been effected with little displacement so that all varieties can be observed in their correct sequence.