18 
GEOLOGY OF THE THIRD DISTRICT. 
northeastern part of Oneida, and the whole of Lewis county east of Black river. They form 
a continuous mass, being the south and west part of that comparatively immense and beauti¬ 
fully circumscribed nucleus, which from a height, according to Professor Emmons, of 
nearly six thousand feet, descends with great irregularity, and disappears under the transition 
rocks which encircle it, and which border the St. Lawrence, the Champlain, the Mohawk and 
the Black river. To the southwest, the primary rocks do not again appear, until they rise to 
form the Ozark mountains of Arkansas, and the Iron mountain of Missouri. 
The primary rocks of the district belong to the third range of the United States. The 
ranges differ in many of their characters, and in their geographical position. The first is the 
granite, having the characters usually given of this rock. It contains few extraneous mine¬ 
rals, is deficient in limestone, in iron ore, and disposed to decomposition. It is an extensive 
rock from Virginia south, and is the first rock which is met with going west from the coast. 
The second range is the gneiss. This is the same in all respects with that of the east part of 
the State, and extends through the Union, being placed between the other two ranges. Its 
characters and associates are pretty uniform throughout its long course. The third differs 
greatly from the other two : Mica is rare ; amphibole more abundant; less disposed to decom¬ 
position than the two other ranges; rich in magnetic iron ore, which is only incidentally 
found in the others, showing no mine of it in either of those ranges. The third range is 
extremely rich in extraneous minerals, and lies to the west of the other two. 
A reference to the map will show the boundaries in the third district, of the Primary and 
Transition classes. Through Lewis county, Oneida and Herkimer, they are well defined, 
being natural ones formed by Black river, the valley of Black creek and Spruce creek. In 
Montgomery the boundary is wholly artificial, and a reference to the map is necessary to 
understand it. The great mass lies to the north of the road which leads from Garoga Post- 
office, by Lasselsville to Brocket’s bridge, on East Canada creek. East of the Post-office, 
after crossing Klip Hill, it pursues a northeast course, keeping within a mile or two to the 
northwest of the villages of Kingsborough, Mayfield Corners and Cranberry Post-office, to 
Sacondaga river; down which river it passes on the northeast side, forming the high hill or 
low mountain which runs parallel with the river, and for a mile and more from its bank. It 
joins the high range of primary hills in Saratoga county, of which it forms a part. In the 
four counties, its outline is that of a segment of a rude circle. 
The characteristic features of the Primary region are its high insulated ridges, with parts 
more or less level between them ; the extent of level surface somewhat considerable, in 
which are numerous lakes, ponds and meadows. The most hilly portions seen, were near to 
the east side of Montgomery, the greater part of the northern portion of Herkimer, the north¬ 
west part of Oneida, and the east part of Lewis ; the hills diminishing north, corresponding 
with the slope at the northwest of St. Lawrence county. Some of the hills, such as Oak 
mountain, Royal hill, Kingsbury mountain, &c. appear to owe their elevation above the 
surrounding surface, to the same cause which raised the Noses, Little falls, &c., their forms 
elongated and mural being too regular and abrupt to be the relics of denudation. These 
high abrupt primary ranges are more numerous in Saratoga county, and show the Cham- 
