GEOLOGY. 235 



found on the Wassemon, though we are unwilHng to pro- 

 nounce upon their identity. 



n^ ***** * 



" It would remain for us, in order to complete this view 

 of the geology of the Falls, to inquire whether the limestone 

 observed at the falls corresponds with that superior to the 

 sandstone south of the Wisconsin ; and if that found near the 

 level of the river at the fort be analogous to that observed 

 under the sandstone between the Wisconsin and Wassemon. 

 We shall not affect a degree of certainty which we do not 

 possess, but we may be permitted to advance an opinion that 

 the sandstone is probably of analogous formation, and that, 

 therefore, the strata of limestone which we found at the Falls 

 correspond with that stratum, of whose existence, at a former 

 period, between the Wassemon and Wisconsin, we think we 

 have evident proofs. We have in our possession specimens 

 taken in both places, filled with, apparently, the same organic 

 remains, and exhibiting characters in the rock which corre- 

 spond as well as could be expected from pieces collected at 

 three hundred miles' distance from each other." — Long^s 2d 

 Exped., vol. i., p. 306, et seq. 



Extracts from tJie Report of a Geological Exploration in 

 part, of Ioioa,Wisconsin and Illinois. By D. D. Owen. 



" Throughout the Western States, generally, the secondary 

 formation prevails, covered up in various locations, some- 

 times to a considerable depth, by recent alluvial and diluvial 

 deposits. 



" This secondary series of rocks comprehends various sub- 

 divisions of distinct character and invariable succession, 

 which, in their turn, have been again subdivided. 



