170 Foliation and Sedimentation— Laivma. 
gueisse-s of the region in question, I promised a reply. I- was 
called away to other duties, however, immediately after, and 
have not till the present had an opportunity of fulfilling my 
promise. Now that the time is at my disposal I shall endeavor, 
while gratefully acknowledging the fair and sincere spirit in 
which Prof. Winchell has examined and reviewed my work, to 
show that many of the contentions advanced by him in opposi- 
tion to my own views are untenable, and that others argue 
strongly for and not against the position I have taken. The 
question at issue is not merely one of controversial interest, but 
is as Prof. W. states of fundamental importance in Archaean 
geology. 
To state the question fairly I must quote the proposition 
which Prof. W. combats in the words in which I first stated it: 
"It is highly improbable that the foliation of the gneiss has anything 
to do with an original sedimentation. Numerous instances have been cited 
in the preceding pages of the brecciated condition of the contact of the 
gneiss and schist. Gneissic foliation is seen to have been developed in a 
rock, which was once in so liquid or viscid a condition as to permit the 
passage through it of angular blocks of schist, to considerable distances 
from the source from which they were detached. A rock, to have been in 
a state so yielding, must necessarily have had all traces of an original sed- 
imentation, if any such existed, obliterated. Furthermore, the existence 
of a well marked foliated structure in dykes which have been injected 
within the schist, both parallel and transverse to its lamination, and 
which are sometimes traceable in unbroken continuity with the main area 
of the gneiss, proves conclusively that such foliation was induced in the 
rock subsequent to its having been soft enough to have undergone injec- 
tion, and therefore to have had any traces of sedimentation destroyed. In 
other words, the foliation of the granitoid gneisses is developed in rocks 
once viscid or plastic, quite independently of any arrangement due to 
sedimentation they may or may not liave possessed. This conclusion does 
not necessarily imply that the gneiss and schist may not have been origi- 
nally sedimentary and conformable. As a matter of opinion* I incline to 
the belief that the granitoid gneisses of the Laurentian were never aqueous 
sediments, but the conclusion, which the facts adduced lead to, is independ- 
ent of either the origin of the rocks or their original stratigraphical rela- 
tions. It simply proves that foliation is no indication of sedimentation and 
so far as the question of conformity depends upon it there is nothing to 
go by." 
This being my position on the question, Prof. W. proceeds to 
assail it, and in a categorical series of fourteen propositions to 
* I have now abandoned this opinion which was based on the absence of evidence 
to the contrary and I have always Mt myselt quite free to recognize that the Lauren- 
tian rocks were once sediments or volcanic rocks or surface rocks of any kind. 
