CAAT Ee valale: 
THE KEWEENAWAN ROCKS OF THE NORTH AND EAST 
SHORES OF LAKE SUPERIOR. 
INTRODUCTORY.—Large rock exposures of the North and East Shores.—Contrast between the North 
and South Shores.—Distribution of the Keweenawan rocks of the North and East Shores. 
SEcTION I. THE MINNESOTA COAST.—Examinations made on this coast.—Lakeward dip of the rocks.— 
General review of relation of coast line to strike and dip of the rocks.—Crescentic courses of the 
rock belts of this region.—Stratigraphical succession of the Minnesota coast.—The several 
subordinate groups described in detail; the Saint Louis gabbros; the Duluth Group; the Lester 
River Group; the Agate Bay Group; the Duluth, Lester River, and Agate Bay Groups at the east 
end of the Minnesota coast; the Beaver Bay Group; the Temperance River Group. 
Suction II. IsL—E ROYALE AND THE NEIGHBORING MAINLAND TO NIPIGON Bay.—Relation of the Isle 
Royale rocks to those of the Minnesota coast.—Sources of information with regard to this 
region.—Isle Royale and its geology.—The Keweenawan rocks of the mainland between Thunder 
Bay and Nipigon Bay.—The Nipigon Lake basin and its geology. 
Srction III. MicurercoreEN ISLAND AND THE EAST COAST.—Michipicoten Island; accounts of its 
geology, by Logan and Macfarlane.—Microscopic examinations of its rocks.—The east coast; 
accounts by Logan and Macfarlane.—Cape Choyye.—Pointe aux Mines.—Mamainse.—Batche. 
wanung Bay.—Gros Cap. 
The north and east coasts of Lake Superior together form one of the 
finest lines of rock exposure in the world. From Duluth to the Sault— 
a distance of over 600 miles, without taking into account any but the 
greatest indentations — the rocks are in nearly continuous exposure. 
Short pebble beaches, usually not more than a few rods in extent, and very 
rarely over a mile, here and there interrupt the absolute continuity of the 
exposure ; but even in these places the rocks on either side of the gap may 
often be connected by outcrops in the woods behind, by islands in front, or 
by continuous rock surfaces not too far beneath the water. Frequently the 
exposures are abrupt cliffs rising from the water’s edge to a height more 
commonly from 20 to 50 feet, less commonly from 50 to 1,000 feet. Only 
rarely are the exposures of soft rocks like sandstone; and for the most part 
they are of some sort of crystalline rock. 
The North Shore thus stands sharply contrasted with the South in its 
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