No. 50.] 
431 
this may appear sufficiently like it, yet it has none of the essential cha- 
racters except color ; and black shale exists in all the formations of 
New- York. Neither is the bituminous character of the rocks an indi- 
cation of coal ; for all the rocks of western New-York, even the hme- 
stone and sandstone, are bituminous. 
The black shale at this place belongs to the Gardeau group ; and 
had the boring proceeded, alternations of green and black shale, with ' 
thin layers of sandstone would have continued to the Gashaqua shale, 
which is seen at the ravine in Wyoming ; and below this the upper 
black shale, &c. It cannot be too often repeated that it is in vain to 
seek for coal in rocks so situated. 
In the ravine west of Warsaw some of the Gardeau rocks are expos- 
ed. In the ravine southwest of the village are found rocks of the Por- 
tage group, though mostly destitute of the characteristic fucoid. In 
this ravine there is a waterfall of 110 feet; which, together with the 
rocks above and below, gives a thickness of 200 feet at this place ; 
they are principally shale with thin layers of sandstone. 
The upper mass of this group may be seen at the falls on Allen's 
creek, near the north line of Gainesville and about three miles south of 
Warsaw village. On elevated ground fiom Sheldon to Warsaw, this 
mass with its vertical fucoid appears in several places along the road. 
The county of Genesee appears to have been less affected by deep 
and violent currents than most others of the same range ; and conse- 
quently the rocks are exposed at fewer points. 
Physical Geography. — Valleys, <^c. — 'The physical geography of 
western New-York, and indeed of the whole State, is a subject of 
much interest, but one to which, thus far, little attention has been 
given. One great difficulty has arisen from the want of knowledge of 
the elevations in different parts of the State. Of many places which 
have been surveyed, we have no published accounts, and of others no 
exact knowledge has been obtained. The published reports do not al- 
ways give' the information sought with regard to particular points. The 
surveys for rail-roads and canals, passing through the lowest valleys, 
do not give the elevation of the higher points, and we are still left with 
only an approximate knowledge of the subject for which we are seek- 
ing.* 
* The tables of elevations published by Professor Henry, in the 1st volume of the 
Transactions of the Albany Institute, are of great interest and importance. 
