f A N:o 1) Igneous Rocks of Sviatoy Noss in Transbaikalia. 29 
| At point 19 was observed a fine example of composite 
dike (fig. 6), intruding an adergneiss. The middle part of 
the dike consists of a dark kersantitic rock composed of 
— hornblende, biotite and feldspar. This rock has been broken 
| 
SE EV 
' 
IT NET 
Ah 
Fig. 6. A Composite dike-breccia in adergneiss, SE-shore 
of Sviatoy Noss. Photo P. Eskola. 
(The hammer-shaft is 42 cm in length.) 
a 
sd 
VTLy 
up into fragments which, somewhat rounded by resorption, 
are enclosed in the aplite. 
3 At point 26 an amphibolite-migmatite is invaded by a 
grey minette dike. This cuts across the aplite dikes and 
the granite veins of the migmatite, but it is itself inter- 
; sected by other narrow (2cm in bredth) dikes of aplite. 
The minette, examined under the microscope was found 
to consist of plagioclase (Abg,), biotite, quartz and a little 
microcline. 
Nå 
