Stratigraphy of the Camlsro-Silurian Rocks of E. Manitoba. G7 



southern portion, the general inclination of this uneven floor, is possibly 

 about parallel to the bedding of the overlying series, but farther north 

 it is more abrupt, as at Dog Head, where a narrow channel has been 

 eroded, and is kept free by cuirents in the lake, through the soft under- 

 lying sandstone, a depth of 1 1 2 feet has been reached at a little over 

 one half mile from the Archie in rocks of the east shore. 



THE WINNIPEG SANDSTONE. 



The basal beds of this series of'Cambro-Silurian rocks, is, on its 

 eastern outcrop, a sandstone, which is probably a shore deposit of an 

 advancing sea, and therefore, not altogether similar in age., to 

 those to the south, at the base of the Cambro Silurian in Minnesota, 

 but may possibly be a trifle later. The fossils found, so far, are rather 

 indefinite, and would seem to be much the same as species in the next 

 overlying series of limestones. Mr. Whiteaves, the palaeontologist of 

 the Geological Survey, intends making a study of these in the near 

 future. The exposures on the lake show a thickness of about 100 feet 

 of friable fine grained sandstone with a few feet of dark grey green 

 shales toward the upper part of the section. The lower half resting on 

 the Archaean, is seen on the eastern end of Punk Island as a pure, clean 

 fine-grained sandstone, lightly cemented, and very friable. In several 

 places it is somewhat harder, and of a reddish colour/from a staining of 

 iron oxide, derived from the Huronion beds immediately underlying 

 portions of the island. On Deer Island, to the west of this, the upper 

 part of the sandstone is seen, overlaid by limestone. The sand is in- 

 terbedded with shaly bands, and the sections exposed at several points, 

 show an irregularity in the deposition of this dark material. The 

 sections of this sandstone and shale at the several localities on the lake 

 are all near the eastern edge of this deposit, and probably near the 

 ancient shore line. . 



Comparisons with sections elsewhere made in Manitoba in drill 

 holes, show an increasing deposit of the shaly beds in the upper part 

 of the sandstone. For example, at Selkirk, the drilling extended 36 feet 

 below the limestone, through shales and soft rocks, before striking a 

 porous layer of pebbles and sand. Again at Rosenfeld,* a much greater 



*On certain borings in Manitoba and the Northwest Territories by Dr. G. M. 

 Dawson, Trans. Royal Society of Canada, Vol. IV, ft. IV, 1886. 



