GABBROS OF EAST SOOKE AND ROCKY POINT. 
45 
It seems probable that this control of the escape of solutions 
bj jointing and faulting may be the explanation of the usual 
absence of hornblendite types among the igneous veins formed as 
the last products of differentiation of other magmas. If jointing 
was deferred until the, magma had cooled to a point where the 
solutions could not carry lime, iron, and magnesia, except in 
small quantities, nothing but aplitic veins would be formed. This 
might have been the case in the mass under discussion, had not 
regional faulting fissured the rocks, soon after their consolida- 
tion. 
Additional Considerations and Conclusions . 
Behaviour of Lime in the Solution. From the analyses and 
Figure 1 it may be inferred that the concentration of lime in 
the hornblendizing solutions was higher than in the aplitizing. 
It has also been shown that the former were hotter than the latter. 
Projecting this temperature-concentration curve for lime, the 
conclusion may be drawn that still hotter, earlier solutions than 
any of those which have left their record here might carry lime 
in still larger proportions, and deposit it in some form at an 
earlier date. Such deposition of lime would then have ended 
before that of hornblende began. 
Behaviour of Alumina. As shown on Figure 1, there was 
some loss of alumina from the wall rocks during alteration by 
both types of solutions. On the hypothesis of constant volume, 
previously shown to be the most probable, the proportion of 
alumina removed is almost identical in both. It seems probable, 
therefore, that the solubility of alumina in these juvenile solu- 
tions, at whatever temperature, was never great enough to satisfy 
the other bases present for the formation of alumino-silicates, so 
that constant additions to the supply had to be made by drawing 
on the wall rocks. 
SUMMARY. 
The Sooke gabbro is found throughout the Sooke map-area, 
southern Vancouver island, as a number of masses of varying 
size intrusive into the Metchosin basalts. It is of lower Oligocene 
