THE 
AMERICAN GEOLOGIST, 
Vol. XXII. SEPTEMBER, 1898. No. 3 
[Continued from the March Xo.] 
THE GEOLOGY OF THE KEWEENAWAN AREA IN 
NORTHEASTERN MINNESOTA. III. 
By A. H. Elftman, Minneapolis. 
(Plate VII.) 
Part II. GEOLOGY OF THE KEWEE- 
NAWAN SERIES. 
The Map. 
The accompan)ing map, Plate VII, represents the sub- 
divisions of the Keweenawan sefies in Northeastern Minne- 
sota. The boundaries of the various members represent the 
limits of the main bod\' of each member. The Red Rock 
member is so intricate!)' involved with the Gabbro member, 
that it is impossible to represent ever}' small area of red rock 
within the gabbro mass, upon a map of this scale Owing to 
the heavy cover of glacial drift the exact location of the 
boundaries is known often only in widely separated areas. 
The numerous isolated outcrops of the several members of 
the series show the position of the main body of each mem- 
ber. In townships 63 and 64 N. R. 2 E., T. 63 N. ranges 
3 and 4 E. and along the lake Superior coast from Brule 
river to Red Rock ba)', the writer has relied entirely upon 
previous descriptions and an examination of rock specimens 
from that region. The extensive diabase dikes between 
Grand Portage ba)' and Pigeon point, are probably of Ke- 
weenawan age. As no direct evidence to this effect is at hand 
