42 
MUSEUM BULLETIN NO. 30 . 
was completed and the gabbro had undergone a period of joint- 
ing. How long this period was there is no means of ascertaining, 
but, long or short, the cooling intrusive must have lost heat during 
it, and the outflowing solutions must have been correspondingly 
cooler. Again, it has just been shown that the aplitizing solutions 
were less concentrated in magnesia, lime, and iron than the horn- 
blendizing solutions, and although concentration may depend on 
several factors, it is pre-eminently a function of temperature; 
hence the conclusion is fair that the aplitizing solutions were the 
cooler. In the third place, it has been shown by Bowen, in the 
paper already cited, that the presence of blotite in a rock is 
indicative of high concentration of volatile constituents, of which 
the chief is* water; hornblende indicates lower concentration of 
water, augite, a magma poor in water. The ferromagnesian 
mineral crystallizing in the aplite veins is biotite, that in equil- 
ibrium with the homblendizing solutions was hornblende. If 
Bowen's conclusions are correct, therefore, the aplitizing solu- 
tions must have been higher in water than the homblendizing. 
The increased concentration of water could only have been 
attained by the crystallization from solution of part of the con- 
tained solids, a function of decreasing temperature mainly ; hence 
again the aplitizing solutions must have been the cooler of the 
two. 
Summary of Facts Known Regarding the Homblendizing and 
Aplitizing Solutions . 
It has been shown that both the hornblendites and the aplites 
are deposits from aqueo-igneous solutions exhaled from the 
Sooke gabbro during its final stages of cooling. Both types of 
solutions escaped through joint and fault fissures, altering the 
rocks as they passed. Both types contained all the component 
rock oxides, although in different proportions ; the homblendizing 
solutions were the mors concentrated, perhaps in all constituents, 
but certainly at least, in magnesia, lime, and iron. The aplitizing 
solutions were cooler, and contained a larger proportion of water. 
Corresponding to these differences there was a marked difference 
in the metamorphic effects of the two solutions. The homblend- 
