GABBROS OF EAST SOOKE AND ROCKY POINT. 
21 
INTERNAL STRUCTURAL RELATIONS. 
Spatial and Contact Relations. 
The relations between the different rocks of the mass are of 
two classes ; general arrangement in space, and contact relations. 
Although both of these have been taken up to some extent, the 
previous statements are here recapitulated and somewhat 
enlarged. 
In space, the olivine gabbro occupies the whole central part 
of the intrusive. If its upper horizons were originally of other 
composition, all trace of this condition, except the anorthosite 
remnant on the summit of mount Maguire, has been removed by 
erosion. Erosion has also eaten deeply into the edges of the mass 
locally, especially on the western and southeastern coasts, and 
there the olivine gabbro outcrops directly on the seashore. The 
augite gabbro is found over the remainder of the coast-line, 
occupying a position peripheral to the olivine gabbro and form- 
ing a partly removed shell around it. It is found in a narrow 
strip around the southwestern end of the peninsula, and as a 
wider band along the north coast. Anorthosite does not occur 
in any continuous mass, but small bodies of it are scattered 
throughout the strip of augite gabbro, and larger bodies at oi 
near the contact of the olivine and augite gabbros. Thus the 
largest mass on mount Maguire is directly underlain by olivine 
gabbro, and the moderately large masses on the western coast 
and near Beechey head lie fairly close to the contact of the oli- 
vine and augite gabbros. The only granite mass found on Sooke 
peninsula occurs at the extreme southwestern tip, on Possession 
point, intruding the augite gabbro there ; this point is supposed to 
be very near the original periphery of the body, as the augite 
gabbro here forms an extensive contact breccia with the Metcho- 
sin basalt, and such bands of contact breccia are nowhere else 
found to be more than 200 or 300 feet in width. 
Turning now to the relations between the different rock 
varieties as found at their contacts, it is necessary to consider 
those between the different varieties of each principal rock type 
