A tholeiitic phase of the quartz-dolerite magma of central Scotland

Abstract

The Permo-Carboniferous quartz-dolerites of central Scotland are generally holocrystalline, and only two intrusions amongst them with a fresh vitreous base have been recorded—those of Dalmeny in West Lothian, andKinkellnear Kirkintilloch (northof Glasgow). Both rocks have already been described briefly, but in view of their many interesting features a more thorough treatment seems desirable, particularly as they have a bearing on some recent theories of magmatie differentiation advanced by Dr. C. N. Fenner.