390 APPENDIX. 



pected to yield thin seams of coal, in distant places, l)ut no deposit 

 of this mineral which will reward exploration in this or its super- 

 incumbent series of rocks, the slates, limestones, &;c. It will re- 

 sult, that the coal-measures, properly so denominated, are a prior 

 deposit in the order of series ; and, should they hereafter be found, 

 such a discovery must take place above the range of the sand- 

 stone, which is the basis rock at Niagara and Genesee Falls. 



Having premised the character of the sandstone, all the series 

 occupying a position above it must derive their character, as 

 secondary deposits, from this. The limestone cannot, therefore, 

 be a part of the carboniferous or " medial." The slates, as shown 

 at Cashong, are fragmentary, and rather nearer slaty grau- 

 waks. The arenaceous and calcareous upper deposits assume 

 nearly the position of the oolitic series, and, in fact, ought, in 

 some localities, to be regarded as equivalents. 



"Westerx Coal-Mines. — Much of the data employed in these 

 inquiries is the result of previous examinations of the great coal 

 deposits in the Ohio Valley, and other parts of the western country. 

 Here we have the coal-sandstone and the slate clay, with slate, 

 &c., alternating with the coal-measures. Such is the order of 

 deposits at the junction of the Alleghany and Monongahela, where 

 the formation is well developed, and where there exists, too, in 

 the elevated valley hills, several repetitions of the series. The 

 zechstone, or compact limestone, which is a pervading rock in 

 the Mississippi Yalley, occupies a position next above the great 

 Mississippi sandstone.* It may always be distinguished from the 

 shelly, entrochal limestone of the Genesee,t by the absence of 

 gypsum and of the fetid odor emitted on fracture. 



Alleghany Yalley. — A question of interest, in connection 

 with the extent of the Ohio Yalley coal-formation, arises from 

 the attempt to fix the point to which this formation ascends the 

 Alleghany Yalley — being the direct avenue into Western New 

 York. I have examined this valley in its entire length between 

 Pittsburg and Olean, in Cattaraugus County, and have not been 

 able to observe that there are any evidences of its termination 



* This formation cannot be called "red sandstone," from its being generally 

 white or gray, but appears to occupy the position of the "horizontal red sandstone" 

 among European rocks. 



•}■ The cornutiferous limerock of Mr. Eaton. 



