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 Wisacode 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 Wisacode 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 Wisacode, 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 Wisacode, 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. G41 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. Norwood. 



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 



