GEOLOGY. 229 



" The rock is a white sandstone formed of fragments of 

 fine transparent and colorless quartz, united l)y a cement, 

 which, in some parts, appears to be ferruginous, while, in 

 others, it is colorless, and probably of a calcareous nature. 

 In some parts the cement is quite invisible, and would almost 

 lead to the belief that the union of the grains was a crystal- 

 line one. Til is sandstone appears in fragments or tatters, 

 and constitutes the remains of a formation which probably 

 covered the whole of the limestone, at least in this part of 

 the country. That it is above the limestone no doubt can 

 exist in our minds, as we saw the immediate superposition. It 

 sometimes appears, it is true, to sink below the level of that 

 rock, and this led us, at first, to apprehend that there miglit 

 be an alternation of strata, but a careful examination of all 

 these spots has left no doubt in our minds, that in these 

 cases the sandstone is deposited in coves or valleys formed in 

 the limestone previous to the deposition of the sandstone. 

 The cases are, however, not common, and we may safely 

 state, as a general rule, that not only the sandstone is rela- 

 tively above the limestone, but that it is even, in almost all 

 cases, at a greater absolute elevation, and the spot at which 

 we first met with it, west of the Wassemon, was considera- 

 bly elevated above the usual level of the limestone ; for 

 wherever the sandstone has retained its position, it has pro- 

 tected the limestone against decomposition, and hence, in 

 such places, the latter rock still continues to rise to a higher 

 level than where it is laid bare, and exposed to the destruc- 

 tive influence of atmospherical agents. We also observed 

 very distinctly, that while the valleys formed in the limestone 

 at a time anterior to the deposition of the sandstone were 

 few, those produced subsequently were numerous, as was 

 indicated by the great rougiiness and unevcnness of the sand 



