396 DESCRIPTION OF THE COUNTRY BORDERING 
support the capping of altered slates. As the Eastern Palisades are approached, the 
sedimentary rocks become more bent and undulating, in consequence of the nume- 
rous narrow prismatic dikes which traverse them. The rock composing the Eastern 
Palisades (No. 57) is, in every respect, like that of the Palisades near Baptism 
River, as well as the metamorphosed siliceous slates of Wisacodé and Pigeon Rivers. 
The Palisade rock here forms a point thirty-six feet in height, which projects into 
the Lake for the distance of one hundred feet. It extends back to the first high 
greenstone ridge in a tolerably level plain, covered by scanty vegetation. Like the 
metamorphosed shales below Bitobigungk, it lies between two trap ridges, and is 
traversed by narrow trap dikes, having different bearings, which do not appear to 
have caused much disturbance in the sedimentary rocks at the time of their erup- 
tion. Between this point and the mouth of Wisacodé River, the rocks exposed on 
the shore vary in height from three to twenty feet, and are composed, in the bottoms 
of the bays, of altered slates overlaid by bedded trap, and at the points, by the 
remains of a great north-45°-east dike (No. 58.) Immediately below the mouth 
of the Wisacodé, in the first bay, the shores are composed of No. 638. 
Along the extent of coast just described, numerous narrow trap dikes traverse 
the bedded rocks, differing in composition and bearing. In the second small bay 
below the Wisacodé, a dike of greenish-coloured trap, bearing north 60° west, inter- 
sects the north-45°-east dike mentioned above. These dikes vary in width from 
three to twenty feet, and bear east and west, north and south, north 20° east, and 
north 45° west. Nos. 641 and 642 show the general character of the rock com- 
posing the dikes, most of which are shown on the Geological Map. 
At the northeast end of the island, in Grand Portage Bay, is a narrow dike, 
bearing west 10° north. 
At the point opposite the centre of the large island, in the cluster below Waswa- 
goning Bay, is a dike bearing east and west, accompanied by a vein of calcite from 
two to three feet wide. In its course across the bay, the dike forms several rock- 
islands. A little below this is a heavy east-10°-north dike, which resembles No. 
636. It imparts to the sedimentary rocks in near contact with it, much of its litho- 
logical character. This dike continues along the point to the projection opposite 
the northeast end of the island (No. 649). The island is composed, mostly, of No. 
650, which bears east and west, and is concerned in the formation of most of the 
islands here. It crosses at the bottom of the bay and runs inland. 
At Grand Portage Bay are two ancient lake beaches, the first one about one hun- 
dred yards back of the present beach, the other three hundred yards further back. 
The first one is, like all the present beaches, highest next the Lake, with a descent 
of several feet to the base of the second one. 
The details of the Coast Section, from Grand Portage Bay to Pigeon Point, are 
given, in the following Report, by Major Richard Owen, who made the examina- 
tions. 
Dr. J. G. Norwoop. 
Sir,—Having received instructions from you, on the 17th July, 1849, to take the 
canoe, with some of the men, and examine, in detail, the coast, from the mouth of 
