380 



DESCRIPTION OF THE COUNTRY 



BORDERING 



gorges still show large sections of holes, some of them, as along the margin of the 

 upper gorge, high above the present water-level ; while below them are the remains 

 of potholes, some wholly, and others partially, broken into by the channel. In 

 addition to the enlargement of the potholes by grinding, the freezing of water in 

 them in winter has contributed, no doubt, towards breaking them into the gorge. 

 The preceding sketch will illustrate the manner in which they occur. 



The highest point near the lake-shore, between Fond du Lac Superieure and 

 Pigeon River, is a hill which bears due north from a point on the shore half a mile 

 below the mouth of Kawimbash River. The distance from that point to the sum- 

 mit of the hill is about four miles. It was proposed by Colonel Whittlesey, who 

 ascended it in company with Mr. R. B. Carlton, in 1848, to call it Carlton's Peak. 

 It was measured, barometrically, by Major Richard Owen, in 1849, and the summit 

 found to be nine hundred and thirty-seven feet above the level of the Lake. It is 

 a prominent and important landmark to the voyageur, and commands a view of 

 Point Keweenaw, the Porcupine Mountains, and a long extent of the south coast of 

 the Lake. It also overlooks a large section of the country to the north. At the 

 distance of twelve or fifteen miles to the northwest are several ridges, which appear 

 to rise to about the same height as the Peak, and one of them, perhaps, is higher. 

 The summits of the highest intervening ridges, some of which were measured, are 

 only a little over seven hundred feet above the lake-level. 



The summit of Carlton's Peak is composed entirely of felspar rock, which appears 

 to have been erupted in the form of a dike, bearing east and west (No. 148). On 

 the side next the Lake, and one hundred and seventy feet below the summit, No. 

 149 appears, bearing northeast and southwest; and one hundred and ninety-six 

 feet below this, where the gentle descent to the Lake begins, No. 150 comes up, 

 and forms a ridge about sixty feet above the general slope. Continuing to descend, 

 a quarter of a mile further, is a ridge of greenstone, eighty feet high ; and between 

 this and the Lake are two low ridges of No. 150, which appear to be the same as 

 the overlying rock found at numerous points on the lake-shore. Between all these 

 ridges cedar swamps occur, and the rocks are entirely concealed, except at the 

 summits of the ridges. The rocks underlying No. 150, however, are believed to be 

 the same as those found on Kawimbash and Inaonani Rivers, and at the lake- 

 shore. An analysis of the rock forming this peak (No. 148), yielded the results 

 given below.* 



* BB. — Fuses with difficulty on the edges ; with soda on charcoal, forms a white enamel ; with borax, 

 a colourless glass; with solution of cobalt, the fused edges become blue. Held in the forceps, a thin 

 splinter fuses to a globule at the point, with effervescence, the globule being, when cool, white and 

 blebby. Sp. Gr. 2-710. — Streak grayish white. 



Matters insoluble in CI H. -522. 



Silica, ...... -462 



Alumina, with a trace of iron. . . -346 



Magnesia, ...... -015 



Lime, ...... -115 



Potash, ..... -017 



Soda, ...... -010 



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