GENESEE SLATE. 169 



Mr. Hall in the septaria of the same slate in the fourth district, and the discovery in the ravine 

 at Ogden's ferry was made conjointly with him. 



The Genesee slate was not distinctly recognized east of the town of Smyrna in Chenango 

 county, probably owing to intermixture with sandstone, and its fossils not having been noticed. 

 West of that town it may be seen in several points along the road from Smyrna to De Ruyter ; 

 and at the latter village also, which it underlies, and appears in all the side-hills around it. 

 It is found near the dividing line of the counties of Cortland and Onondaga, forming the base 

 of the hills, especially where the towns of Fabius, Truxton, Preble, and Tully join. It 

 appears in many parts of those towns, and may readily be found by its black color, slaty frac- 

 ture, and being between the Tully limestone and the sandstone flags of the base of the Ithaca 

 group. Below Preble comers, where it forms the base of the abrupt hill which rises from 

 the bottom of the valley, it is said from Indian tradition to contain coal, for which there is 

 no other foundation than the resemblance which it bears to coal slate or shale. 



The slate appears in the northern part of Spaiford, upon the Tully limestone ; on both 

 sides of Otisco valley, at the head of the lake ; near Vanetten's, in the northern part of 

 Sempronius ; along the side-hills of the valley at the head of Skaneateles lake ; and in 

 numerous places in Scipio, and along Cayuga lake to the west of the towns of Venice and 

 Genoa, and on the west side of the town of Lansing. 



In the ravines east of Ludlowville, the slate is well exposed from the Tully limestone 

 upwards, presenting a mass which cannot be less than from eighty to one hundred feet in 

 thickness. In the third ravine there are two high falls formed by this rock, which have some 

 beauty, owing in part to the regular joints of the rocks being, as before mentioned, nearly at 

 right angles to each other ; the middle block having been removed, the edges and angles 

 rounded, and the water falling in the direction of the joint. Near the Tully limestone, in 

 the fissures of the slate, are two narrow veins of semi-crystalline rock of a blackish brown 

 color, becoming olive by alteration. It appears to be a mixture chiefly of serpentine and 

 limestone, having the appearance of a Trap rock. There are also two similar veins, near the 

 foot of the second falls, in the same ravine. Both sets of veins traverse the creek at nearly 

 right angles to its course. 



The greatest exposition of the slate is along Cayuga lake, south of Ludlowville, along which 

 it ranges above the Tully limestone, and below the Ithaca group, for a considerable distance. 

 It often shows, where sheltered, a saline efflorescence of two or more different salts. The 

 same was also noticed in Otisco valley, or depression south of the lake. 



Gkol. 3d Dist. 22 



