SirS Dr. Bigsby oti the Geology of Lake Ontario. 



and Moira ; and crossing the height of land from this lake to 

 that of Simcoe, I never could either see or hear of the muria- 

 tiferous rock itself. At the west end of Ontario, and through- 

 out the eastern part of the Niagara district, it emerges in the 

 ravines and beds of streams. Of the rocks above this, I have 

 only seen what I consider to belong to the calciferous slate. 

 Beginning with the lowest, I shall now give a short but suffi- 

 cient sketch of the rocks of this shore in succession from the 

 north-east, including also those of its outlet. 



Mr. Eaton found, inclining upon the gneiss of Macomb's 

 Mountains, calciferous sandstone : on that of the Thousand 

 Islands and of the vicinity of Kingston, there is no such stra- 

 tum ; but in place of it, from Brockville to seven miles above 

 Gananoque (forty-nine miles), there is a hard quartzy sand- 

 stone in thin layers placed horizontally or nearly so. From 

 three miles to ten miles above Brockville, it forms on the north 

 side of the outlet extremely picturesque cliffs surmounted by 

 green slopes, through whose herbage the gray rock occasionally 

 peeps. Seven miles from the above town, on the same side 

 of the river, two mounds of fine granular gneiss, within a few 

 feet of each other, make part of the precipice without disturb- 

 ing the sandstone in close contact with it. The interval be- 

 tween them has formed into a shallow cave. The sandstone is 

 most plentiful on the east side of this primitive barrier; and in 

 the interior, a few miles west and north-west of Brockville, it 

 appears among the gneiss mounds as the precipitous sides of 

 valleys, and as obstructions to water-courses. 



This sandstone, both in large tracts, and in alternating layers 

 of the same cliff, is gray and white, rarely spotted with car- 

 buret of iron. It is granular, fine and coarse, and occasion- 

 ally contains nodules of crystalline quartz from the size of a 

 mustard-seed to that of a child's head. These nodules are seen 

 in irregular and sometimes thick beds at the lower parts of 

 the stratum, on the river side, from four and four and a half to 

 seven miles above Brockville. Here they are not of milky 

 quartz, but are hyaline, or brown with iron, in which case the 

 imbedding sandstone is also brown. At Gananoque this rock 

 forms a natural quay for commercial purposes. Here the 

 larger nodules (white) are on the surface, the smaller scattered 

 through the body of the layers. At the south-west end of this 

 arenaceous platform there are many balls of sandstone six 

 inches in diameter, with onion-like concentric coats, all of the 

 same substance as the containing rock. Six miles above Ga- 

 nanoque, the north main shore of a strait, opposite the end 

 of Hour Island, is composed of a pudding-stone of very large 

 rounded masses of quartz, some of which are of the milky kind. 



They 



