THE EASTERN SANDSTONE ON BETE GRISE BAY. 353 
relations subsisting between the Keweenawan rocks and the Eastern Sand- 
stone, I follow the northern junction westward from Béte Grise Bay to Lake 
Agogebic, and then the southern from that lake eastward. 
The north shore of Béte Grise Bay, as shown ona previous page, is made 
of low cliffs of Keweenawan diabase and melaphyr, with some quartzifer- 
ous porphyry, all dipping northward at a high angle; while the west shore of 
the bay lies in the lowland underlain by the Eastern Sandstone. In the angle 
of the bay the two formations come together, and their contact may be fol- 
lowed for a long distance. The sandstone, of which a considerable thickness 
may be seen in continuous exposure, dips southward at angles varying from 
45°? at the contact to 30° and less at the point farthest removed from the 
contact. It is made up of alternating whitish, quartzose, fine-grained lay- 
ers, and thinner ones of red shale; the latter running from a few inches to 
several feet in thickness. Some of the red layers are strongly conglom- 
eratic, the pebbles being generally of small size and often angular, and 
composed in the main of red felsite, but also in some measure of the ordinary 
Keweenawan diabase and melaphyr. The accompanying section, repre- 
Fia, 30.—Showing relation of the Eastern Sandstone and Keweenawan melaphyr, Béte Grise 
Bay. Length of section about 150 feet. 
senting a length of about 150 feet, is designed to illustrate the nature of 
this contact. The junction line between the sandstone and the older rocks 
is quite irregular, and as the shore of the bay is followed eastward, patches 
of the sandstone are seen remaining in embayments of the older rocks on 
the cliff-side. Underneath the clear waters of the lake the beveled edges 
of the alternating bands of red and white sandstone may be traced for 
hundreds of feet in great sweeping curves. On the south point of Béte 
Grise Bay, below the ship canal, the sandstone lies horizontally. 
‘Not 78°, as reported by Foster and Whitney, op. cit., p. 112. 
23 LS 
