Kawishiwin Agglomerate.— Winchell. 36T 
saussurite, leucoxene, serpentine, hornblende, etc, and these 
would, in some places be consolidated into rock which would 
possess many of the characters of an altered igneous rock, but 
would manifest more or less evidently the stamp of the ocean. 
There would be occasional foreign ingredients, particularly rounded 
quartz grains, and there would be in many places a fine intermix- 
ture of chemically precipitated silica, or perhaps of: chemically 
precipitated oxide of iron, the last two uniting to form the well 
known jasperoid hematites. Again there would have to be many 
places, as there are, where the resultant rock would be very fine- 
grained, the ejecta having been totally disintegrated “and reduced 
toa pulp or voleaniec mud. When this accumulation was rapid there 
could be but little opportunity for the formation of characteristic 
sedimentary structures, but when it was slow the most evident sed- 
imentary banding would result. There would be many places where 
the non-stratified would gradually acquire a stratified structure. 
If we attempt therefore to effect such a compromise between 
the opposing disputants as the facts seem to warrant, we have to 
allow that the stratigraphist has a show of reason in insisting that 
oceanic structures permeate these greenstones, although the sedi- 
mentary banding is sometimes wholly wanting over large areas. 
We also have to allow that the nature, in general, of the minerals 
contained in these rocks is such as only igneous agencies can ex- 
plain. In other words we must grant the chief contention of 
each party. The source of the rocks was igneous, but their 
structure is aqueous. 
The recognition of this joint agency of oceanic water and 
igneous action in the production of these ambiguous rocks relieves 
the physical geologist of some rather severe strains of imagina- 
tion as well as of dynamic laws to which, without such recogni- 
tion he is compelled to resort. For instance, he has not to con- 
jure up some hypothetical force through which he can explain, if 
he adhere to their sedimentary origin, the conversion of these 
“sediments” into a rock quite unlike ordinary sediments, and the 
absence of the usual structural characters. He has not to assume 
if he adhere to their igneous origin a semi-metamorphosed condi- 
tion or any chemical change capable of converting a vast thick- 
ness of rock, situated at great depths in the crust, from asiliceous 
to a semi-basic character, nor vice versa. It has been gravely 
asserted by some extreme advocates of ‘‘alteration” that the 
