58 
GEOLOGY OF THE THIRD DISTRICT. 
on East and West Canada creeks, but are rare, though the heads are rather numerous ; the 
easy solution of the ligament which binds the crustaceous parts, being probably the cause why 
so few comparatively are found whole. 
Out of this rock, in the district, I have met with but one head, and this was in the Frank¬ 
fort slate, in the gulf to the east of Utica. 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 through 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 rubblestone. 
In Herkimer, it covers the greater part of the space, with some few exceptions, which 
extends from East to West Canada creek, and from 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 under the city of Utica, appearing in the creek to the east of the city, 
whence its 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 
