298 J. P. Kimball on Iron Ores of Marquette, Michigan. 
this series on the North shore, and which have no counterparts 
in Michigan, it will remain for special lithological investigation 
to complete the evidence of the metamorphic origin of the Up- 
per copper-bearing rocks of Lake Superior on the grounds of 
analogy with the conditions of their development in Canada. 
That the question has been left open by the Canadian geologists, 
is apparent from the fact that the stratified greenstones of this 
series, in a chapter by Mr. T. Sterry Hunt, are described as the 
stratigraphical and lithological equivalents of the diorites of the 
uebec Group examined by him in Eastern Canada, which he 
asserts to be altered sediments, and to pass into chloritie, epidotie, 
and hornblendic slates.” 
Allusion has already been made to the regularity of the flex: 
st 
tonnées,” and the glacial furrows which these surfaces re 
the most frequent and instructive. It is almost impossl 
meet with an outcropping rock whose character is hibit 
sist weathering influences, the surface of which yee of 
* Geol. Survey of Canada, pp- 612, 614. 
