Quart. Journ. Geol. Soc. Vol. LXX, Pl. LI. 





A Quartz Topaz Vein in Quarry C: 



Fig. 2. Section in Quarry C, showing the 'Reaction Border' 



of Schorl-Rock. 



J.B.S. Photo. 



Be mros«. Collo. Derby 



