22 Geology of Mt. Stephen— McConnelL 
panying these phenomena would be volcanic bombs and ejec- 
tions o£ basic matter such as those mentioned by Dr. Johnson- 
Lavis in the American" Geologist for December, 1888, p. 424. 
These would be thrown to great distances and would appear in 
the sediments where they finally found a resting place as bould- 
ers in a conglomerate of material similar in the composition of 
its matrix to the boulders themselves. 
The eruptive material would be subjected to the action of the 
waters in which it fell. Some of it would be immediately de- 
posited as a basic sediment. Other portions would be mingled 
with siliceous grains derived from the wearing away of other 
adjacent shores. During intervals of volcanic inactivity 
siliceous sediments only would be formed on top of the basic 
deposits already made. Sometimes the fragmental and eruptive 
materials would be mixed in about equal proportions; and again 
one or the other would predominate and the resulting rock 
would be acidic or basic. 
These various inter-gradations and commixtures of different 
materials are all represented in the rocks of the region referred 
to. Although this belt of diabasic schist is immensely thick 
and extends for miles it is no greater than volanic deposits are 
known to be in other places on the globe. Of 'course it is un- 
derstood that the distance across the strike represents only the 
depth or twice the depth, or thickness, of the deposits and not 
the lateral extent of the overflows; for the rocks of the region 
iiave been folded and pressed together, the horizontal strata 
turned to verticality and the prevailing schistosity thus produc- 
ed in the greenstones. 
Minneapolis, December, 1888. 
NOTE ON THE GEOLOGY OF MT. STEPHEN, BRITISH 
COLUMBIA. 
By R. G. McConnkll. 
I have just returned from an extended exploration in the 
north, and find that during my absence several papers have 
been written by Dr. Rominger and Mr. Walcott on the Cam- 
brian fauna of Mt. Stephen. Dr. Rominger, on authority no 
doubt, states in his first paper, published in the Proc. Acad, of 
Nat. Sciences, of Philadelphia, that the locality from which the 
