GABBROS OF EAST SOOKE AND ROCKY POINT. 
31 
basalt. The time interval between the two periods of vulcanism 
was comparatively short. These facts suggest strongly that both 
rocks were ejected from the same underlying reservoir, the 
basalt representing the primary extrusive phase of igneous 
activity, the gabbro the secondary, intrusive phase. Under this 
hypothesis the composition of the Metchosin basalt represents 
that of the original magma, less such volatile constituents as 
were lost during cooling. 
PROOF OF MOVEMENT PRIOR TO CONSOLIDATION. 
The occurrence of the gneissic structures and textures 
already described indicates conclusively that movement took 
place prior to consolidation, but after the mass had begun to get 
rather viscous, partly crystalline, and perhaps in parts wholly 
solid. The gneissic textures could not have been produced after 
consolidation, as movement then would have resulted in granula- 
tion of previously formed crystals and the production of the 
secondary minerals characteristic of dynamic metamorphism. 
The occurrence of gabbros of widely differing compositions in 
long, narrow, gneissic bands, separated from each other by 
sharp gradafions, indicates that when these were formed the 
gabbros were liquid enough to flow, and to be brought into con- 
tact with one another without exhibiting intrusive phenomena, 
yet sufficiently viscous to prevent intermixing. The occurrence 
in some bands of acicular and lath-like pyroxenes, all arranged 
with their long axes parallel, indicates that crystallization had 
at least commenced, although the crystals need not have attained 
their present size when they were thus oriented. The occurrence 
of flow textures in one variety at its contact with another indicates 
that that other must have been very viscous, if not solid. Finally, 
the generally chaotic condition in which the various varieties are 
arranged is also suggestive of movement, although it may also 
be due, partly or wholly, to the freezing of the magma while 
differentiation w f as still incomplete, 
TIME OF MOVEMENT. 
It has been shown that the olivine and augite gabbros were 
rendered gneissic in places, particularly in the peripheral parts 
