Postelsia 
(ox) 
to 
CO 
weight and in percolating waters operating in a 
wide area and through great depths uniform 
material will produce uniform results. Hence 
the evenly assorted particles of quartz, clay, 
carbonaceous material and other incidental 
mineral components produce a rock evenly de- 
formed, made crystalline and uniformly com- 
pacted into a siliceous shale which, for hundreds 
of feet in thickness, is a normal schist of perfect 
erystallime’ texture.’ his’ is due to “the spne: 
cesses of mineral reconstruction reinforced by 
mineral solutions brought in by percolating sub- 
terranean waters. 
With the quartz schists of Providence Cove 
compare the rocks in front of the Station and 
indeed generally along the shore for the distance 
of a mile. At the Station only thin layers of 
the schistose type are to be seen. Lamine of 
alternating hard siliceous bands and argillaceous- 
carbonaceous material of a softer habit prevail. 
This alternation gives evidence that there had 
once been a succession of sand layers and muddy 
shoreline flats succeeding each other many times. 
Again the geologist stands at Port Renfrew 
