68 GEOLOGY OF THE THIRD DISTRICT. 



on Eaat and West Canada creeks, but are rare, though tlie heads are ratlier numerous ; tlje 

 easy solution of Uie hgament which binds the crustaceous parts, being probably the cause why 

 so few comparatively are found whole. 



Out of this rock, in the district, I hare met with but one head, and this was in the Frank- 

 fort slate, in the gulf to the east of lltica. It was very small, not more than half the usual 

 size, resembling those found opposite to Cincinnati, Ohio, as seen in the collection of Mr. 

 Conrad. 



This rock is confined entirely to Montgomery, Herkimer, Oneida and Lewis counties. It 

 enters from Schenectady county, on the south side of the Mohawk, and extends without 

 interruption, excepting along the border of the river from uplifts, to about Whitesborough ; 

 there it crosses the river, and extends north tlu-ough Lewis into Jefferson county. As this 

 rock in the district invariably rests upon the Trenton limestone, so the Frankfort slate and its 

 sandstone follow the Utica slate. Knowing the order of their succession, when either of the 

 two are discovered, the other is readily found ; and a similar remark applies to all rocks 

 which are coextensive masses, or which coexist in any one or more localities. 



On the north side of the Mohawk, the slate covers the large area extending from near 

 Tripes hill to the uplift of the Noses, and north to near the Primary region, forming that 

 fine section of country in which Johnstown is seated. It covers also the area west of that 

 uplift, extending to near Mother creek. These areas show less transported materials than 

 any other observed, the soil which covers the slate being generally the product of the slate. 

 The cliffs along the water courses are of no great height in the Johnstown area, but rise a 

 hundred feet on the Garoga. A small patch was observed in Broadalbin and three in Oppen- 

 heim, one of which is at St. Johnsville, another at the mouth of East Canada creek, and the 

 third on Little Sprite creek, extending from East Canada creek. To the south of the river, 

 it covers nearly one-half of the county on that side, ranging somewhat parallel with the river, 

 extending south from the river, and passing under the Frankfort slate and riibblestone. 



In Herkimer, it covers the greater pari of the space, with some few exceptions, which 

 extends from East to West Canada creek, and firom the Mohawk to Norway. The soil of a 

 very considerable portion of the space it covers, shows that it was produced from the slate. 

 West of the creek, it covers the whole of the area formed by the creek, the river, and the 

 county line of Oneida, with the exception of the top of Hasenclever hill, which consists of the 

 Frankfort slate. 



In Oneida, it passes imder the city of Utica, appearing in the creek to the east of the city, 

 whence iu name. It covers the greater part of the towns of Deerfield and Floyd ; a large 

 portion of Trenton, of Steuben and Western also, and passes into Lewis county towards the 

 middle part of Boonville. 



In Lewis county, its range is uninterrupted, rising to the west of the Trenton limestone, 

 and curving north into Jefferson county. Its characters, mineral and fossil, are without 

 change in all its range. 



The thickness of the slate is well seen on the south side of the river through Montgomery 

 county, where numerous small streams flow in very deep channels cut into the slate : its 



