162 REPORT OF THE AMERICAN COMMITTEE. 
Prof. George H. Williams would prefer to classify the 
eruptives of tlie Archean with their including rocks. 
Prof. W. P. Blake would have eruptives separately classed. 
Prof. C. H. Hitchcock holds that eruptives in the Archean 
should be separated from the ordinary foliated beds on maps and 
in descriptions. He adds, in a note, "I regard the 'Norian' 
system of Hunt, and what he calls the ' Arvonian/ in America, 
as eruptive masses. They should be mapped and described as 
eruptives and not as stratified systems." 
Prof. N. H. Winchell thinks that the eruptives occurring 
in the Archean should hot be considered a part of the strati- 
graphic scheme of classification, but they should be named as a 
part of the classification. They seem to be local, irregular and 
capricious in their distribution. Pie would prefer some classifi- 
cation devoted entirely to them (and for them), but allowed for 
in the stratigraphic column when they are found at any horizon. 
Mr. Thomas Macfarlane holds that the Archean eruptives, 
wherever found, should be classified separately. 
Prof. M. E. Wadsworth answers the question : " No ; they 
are too intimately mingled with the stratified rocks ; and, as yet, 
we do not know what are erupt^ive and what are sedimentary." 
Capt. C E. Dutton says : " I see no reason for treating the 
eruptive rocks of the Archean any differently from those of other 
ages." This means to answer the question, "No." 
Prof. Heilprin : The eruptive rocks of the period should be 
classified aj)art from the Archean rocks proper. 
Prof. Pumpelly : " Only when their eruptive origin is clear 
and of Archean age, and even then, for the present, I would 
follow the old method of relegating them to a separate graphic 
scheme for eruptives." 
Dk. G. M. Dawson: "Separately as in other formations." 
Prof. A. AVinchell says : " They must first be classified 
petrographically, in consequence of the difficulty of determining 
their relative age. But the search for their chronologic succes- 
sion should never be intermitted, and their relations to the Ibeds 
which they intersect should always be recorded." 
To sum up the opinions expressed : 
Prof. Dana, Sir J. W. Dawson, and Prof. George H. 
Williams (the first two in map-making and in the special case 
of foliated eruptives respectively ; the last unreservedly), are the 
