THE EAST COAST OF LAKE SUPERIOR. 349 
be N. 60° W.<22°.” Similar rocks appear again “at the extremity of Gros 
Cap, where there is but a small quantity of the amygdaloid, and where 
trap of a porphyritic character appears to be associated with it. The dip 
ie <4 °.” 
To these quotations I have only to add that the specimens brought to 
me from the above-described places, south of Mamainse Point, show only the 
typically Keweenawan kinds, including not only the basic kinds but also 
red quartziferous porphyry and felsite, the latter from Gros Cap. There is 
still much obscurity hanging about the structural relations of the rocks of the 
east shore from Pointe aux Mines to Gros Cap, and especially is this true of 
the rocks in and about Batchewanung Bay. ‘To add to the difficulties, the 
horizontal Eastern Sandstone seems to be present here, and has been con- 
founded with true Keweenawan sandstones. The peculiar way in which the 
traps and amygdaloids of the latter formation skirt the shores of Batchewa- 
nung Bay, appearing in a small patch even at the deepest point of the bay, 
suggests very strongly the thought that the existence of this bay is deter- 
mined by a peculiar loop-like bend in the general course of the Keweenawan 
belt of the East Shore. Possibly the confused appearances noted on the 
south side of Mamainse by Macfarlane may have something to do with this 
convolution. 
