W. A. Richardson—A Basic Dyke at Charnwood. 175 
centre is much less affected than the margin by cleavage, and its 
quartz in thin section has no very prominent strain phenomena. 
The oe remarkable feature is the presence of laminated margins 
(Fig 3). They occur at both sides of the dyke. At first sight they 
Ce columnar basalt, or certain shearing effects. They really 
lan Marein 
Fic. 3.—Peldar Tor Quarry. Exposure of dolerite dyke showing marginal 
lamination. View looking north. 
