282 IDENTITY OF THE WESTERN FORMATIONS 



features unlike any of the limestones seen in New York or Ohio. 

 By reference to the section, lliis limestone will be seen extending 

 eastward to the vicinity of New Albany, la., and passing beneath 

 the level of the river, near Leavenworth, about fifty miles below. 

 It is visible, forming a cliff- along the river, for nearly the whole 

 of this distance, where it passes under the conglomerate, or its 

 representative, a coarse gray sandstone, showing diagonal lines 

 of deposition, with seams and nodules of hydrate of iron. This 

 limeston© reappears upon the river in several places between 

 Leavenworth and the Wabash, at some of which examinations 

 were made. Beyond the Wabash it reappears and continues to 

 the Mississippi river, forming a low cliif often for many miles in 

 succession. On the Mississippi, above the junction of the Ohio, 

 it soon appears, forming at first but slight elevations, but soon 

 ''rising into cliffs of from one hundred to two hundred feet in 

 height. It presents this character of cliffs nearly to St. Louis, 

 beyond which place it does not rise so high, but continues in 

 view as far as the Rock river, and extends up this stream beyond 

 Dixon's Ferry. From this rapid sketch it will be seen, on refer- 

 ence to the map, that this limestone occupies an extensive area 

 east of the Mississippi river, and sti'etching "westward its limits 

 are unknown. On the south of the Ohio it is known to extend 

 into Tennessee, and from the Reports of Prof. Rogers, it is a very 

 extensive and important rock in Virginia. It thus becomes 

 equally important with any of the gi'cat limestone formations 

 heretofore described in this country, in regard to position and 

 extent. When it shall become more generally known, it will be 

 found a prominent horizon for the proximity of the coal strata, 

 as, in its absence, is the conglomerate fiu-ther cast. 



The examination of this limestone at Leavenworth, gave the 

 following characters : — The lower part of the rock is compact and 

 fine-grained, brealdng with a smooth conchoidal fracture. This 

 portion has been used for lithographic stones, and for small 

 pieces sei-vcs the purpose very well. Above this portion the 

 character is somewhat irregular, with light-colored chert or horn- 

 stone, which is often translucent. I was unable to find any fos- 

 sils thus far upward, in the mass at this place. Above the cherty 



