ESSEX COUNTY. 
281 
The grit-rock of Snake mountain is equivalent to the grey sandstone above the Loraine 
shales ; the latter of which, the reader is to bear in mind, is simply a synonime of the Hud¬ 
son river shales, both terms being occasionally used to designate the same rock : they differ, 
as has been already pointed out, only in the physical changes which each has sustained. 
At Loraine, they are but slightly removed from a horizontal position; while along the Hud¬ 
son river, they have been fractured and elevated in a high angle, or a steep dip to the east 
has been given them. 
The fracture here spoken of, is one of the most interesting and remarkable of all the 
geological phenomena which have been disclosed during the New-York survey. At Snake 
mountain, it is particularly worthy of notice. As has been stated, from the lake to its base, 
it is seven miles; the whole distance is level, and the tertiary is the only formation which 
appears, but we know it rests upon the shaly part of the trenton limestone. The rock then 
continues to the great fracture at the base of the mountain; and we find, when we commence 
the first ascent, that we have left the rock just named, and have passed from that to the calci- 
ferous sandrock. We leave the trenton slate at the base of the mountain. After passing 
over the calciferous sandrock, we soon find ourselves upon the chazy, then upon the trenton 
limestone, utica slate, and Hudson river shales, each in its order, as we ascend the mountain, 
till finally we reach the base of the cliff composed of a hard grit rock, the upper part of 
which is a grey limestone. Sometimes this mass is calcareous throughout its whole extent, 
effervescing strongly with acids ; and then again it is very deficient in lime, the whole mass 
being mostly siliceous. I know of no rock, especially if we take in the grey even-bedded 
sandstone just cited, so given to change; it is sometimes a rubble, sometimes brecciated, and 
again calcareous in various degrees. It is often green, reddish or brown, and frequently the 
upper part is a pure white limestone. 
The fracture at the base of this mountain may be traced a great distance north, appearing, 
however, more distinct where the uplifts are the greatest. The direction and bearing of this 
fracture being once known, it is easily traced; but in order to state the facts revealed, and to 
enter upon details in relation to it, more investigation is required than I have been able to 
give it. 
I shall now proceed and speak of the rocks at Charlotte, opposite the village and township 
of Essex. At this place, their order and position is much the same as at Addison. The 
shore upon the Charlotte side is formed of the trenton limestone: it continues half a mile, 
with an easterly dip; when it thins out, and we pass to the chazy limestone, with a dip to 
the west. The rocks are, however, much concealed, until we ascend the hill upon which 
most of the village stands. Near the church, there is a fine outcrop of the grit-rock which 
has been described. It is here in regular beds, and they are strictly a sandstone, the particles 
of which are angular, but not coarse. At Charlotte, the rock is reddish brown, and the whole 
mass is siliceous, the grey limestone being wanting. As a whole, it has quite a strong resem¬ 
blance to the old red-sandstone. There is, however, one particular in which the sandstone 
differs in all its phases from other siliceous rocks : the particles of quartz are hyaline, or have 
a translucency which we do not discover in other sandstones ; and the mass, though red, is 
Geol. 2d Dist. 36 
