38 
PRIMARY ROCKS. 
W 
K 
CL 
Igneous-« 
Granite_ 
Hypersthene rock. 
Primary limestone. 
Serpentine. 
C Greenstone and trap. 
Plutonic _< Basalt. 
( Lavas. 
f Gneiss_ 
j IVIica slate_ 
Stratified. .Talcose slate_ 
Hornblende_ 
Sienite_ 
Composed of quartz, felspar and mica. 
Composed of quartz, felspar and mica. 
Quartz and mica. 
Quartz and talc. 
Simple. 
Composed of hornblende and felspar. 
Those portions of the State over which Primary rocks prevail, are the Northern and 
Southern highlands. Most of the masses enumerated above are found in both these 
districts. In the northern, which is by far the largest and most important primary district, 
that peculiar variety of granite denominated hypersthene rock prevails very extensively: 
it forms the highest parts of the county of Essex. Surrounding this mass as an irregular 
zone, are beds of granite, primary limestone, and a granitic gneiss. This immense mass 
forms a large portion of the great triangle north of the Mohawk valley. It is here that 
our granitic soils are formed. The beds, however, of granite and other felspathic rocks 
which are disposed to decomposition are not very extensive. We have none of the sandy 
varieties of gneiss or mica slate, which become friable on exposure to the atmosphere, and 
crumble readily and rapidly into soil. Neither have we much of that peculiar granite 
which forms porcelain clay, or it is so limited that mere local effects are observed. Primary 
limestone, associated with granite, and even incorporated with it, exists also, but within 
such narrow limits that it is unnecessary to notice the peculiar soil which is thus jointly 
formed. The rocks on the highest parts of the Adirondacks disintegrate very rapidly, and 
form deposites on the sides of these mountains, which in the progress of time find their 
way to the valleys. 
In estimating the extent of granitic soil, and taking into account all the causes which 
act in distributing it over the State, I am led to adopt the opinion that it exists only in the 
immediate districts underlaid by the primary beds, in such quantity as to give the leading 
characters of a granitic soil. Diluvial action has undoubtedly swept over these districts, 
and carried to the south some of the soil which once rested upon the mountains and in their 
valleys, and it has intermingled with other soils more or less ; still the quantity bears but 
a small porportion to that derived from sedimentary rocks. It is true that the materials of 
these rocks were in many instances of granitic origin, and it is easy often to discern unde¬ 
composed felspar in them. Notwithstanding all this, I am not ready to subscribe to the 
doctrine that all soils are essentially derived from one origin, and that a granitic one; for 
most of the alkalies are lost in the course of the changes to which the fine particles are 
subjected. No one, who has observed the soils of New-York, will hesitate to admit that 
the slate soils are quite different from those of the highland districts. 
