CARBONIFEROUS ROCKS IN RUPERT'S LAND. 



305 



Mountains,) a series of various coloured clays and sand- 

 stones, and beds of sand, often of great thickness. In 

 this series organic remains, excepting leaves of apparently 

 dicotyledonous plants, fossil wood, and obscure casts of 

 shells, are very rarely found, but it everywhere preserves 

 a uniformity of hthological and other characters, point- 

 ing unmistakably to a similarity of physical conditions 

 during their deposition, over immense areas. 



" Although the weight of evidence thus far favours the 

 conclusion that this lower series is of the age of the 

 Lower Green Sand, or Neocomien, of the old world, we 

 yet want positive evidence that portions of it may not be 

 older than any part of the Cretaceous system." 



Judging therefore, solely from the relation which the 

 Cretaceous series bears to formations beneath them in 

 their development through Eupert's Land, Nebraska, and 

 Kansas, we might expect to find on the Eiding Mountain 

 in the vertical section concealed by drift, beneath forma- 

 tion No. 4, either formation No. 1, 2, and 3 of the 

 Nebraska section, or members of the Jurassic and Per- 

 mian as well as the Carboniferous series. 



In the Eeport on the Geological Survey of the State of 

 Iowa, published in 1858, the State geologist, James Hall, 

 advances a highly important view of the relation of the 

 Cretaceous formations to the Carboniferous Series. " To- 

 wards the Eocky Mountains, the palaeozoic rocks are 

 overlaid by the Cretaceous formation, which, in its lower 

 arenaceous members, stretches from the northern limits 

 of the United States territories to the Gulf of Mexico, 

 and throughout a great part of this extent rests uncon- 

 formably upon the coal measures. 



" The line of junction of these two formations is 

 obscured by the denudation of the higher one, and its 

 finely comminuted materials are widely spread over the 



VOL. II. x 



