No. 200.] 
of division. A high and an abrupt elevationjcaused by the appearance of 
the northern edges of the rocks of which it is formed, characterizes 
the southern side of the valley; whilst the northern side, being in ge- 
neral formed of the inclined planes of the surfaces of the rocks which 
pass under and support those of the great escarpement, presents nothing 
in common with its southern border. 
The rocks whose appearance commences in the bottom of the valley 
and which extend north, are the black shale, (with its overlying green 
shale and sandstone,) the Trenton limestone, the birdseye, the calciferous 
sandrock and the gneiss. The arrangement being in the descending or° 
der. Thus the black shale, relatively to the four other rocks, is inva= 
riably the upper one, whilst gneiss is as invariably the lowest. 
The black shale, the Trenton limestone, the birdseye, and the calcife- 
rous, in their course north from the river at different points disappear, 
finally leaving the gneiss, the oldest rock of the district, to form with 
its primary associates, the great northern elevations, and to cover the 
greater part of Montgomery, about three fourths of Herkimer as to 
length, and that part only of Oneida county which forms the town of 
Remsen, including that small triangle in the town of Boonville, which 
lies to the east and north of Black river. 
We have said that the northern side of the valley of the Mohawk, is 
in general formed of the inclined planes of the surfaces of these rocks; 
the exceptions being caused by local or partial uplifts, which have de- 
ranged the surface and destroyed that continuity of strata and rock, and 
created to the casual observer, where the uplifts exist, the greatest ap- 
parent confusion as to their superposition or order of arrangement. 
Uplifts. 
Along the borders of the Mohawk, from the eastern end of Montgo- 
mery to the eastern part of Oneida county, there exists a series of paral- 
lel uplifts, extending but a short distance south of the river; their effect 
in that direction, being confined altogether to the valley, the visible ac- 
tion having ceased before reaching that great massive, the southern boun- 
dary of the valley, which no local action of uplift has disturbed. 
Northwardly the uplifts extend for some distance, but are finally lost 
in the mass of primary rock, of which gneiss, the lowest member of 
the uplift, seems to form the greater part. These uplifts, therefore, are 
parts, or what would be called projections or spurs of the great primary 
