ESSEX COUNTY. 225 



Range and Extent of Granite in Essex. 



This rock occupies but a small extent of territory in tliis county, and it occurs only in 

 insulated beds. From the county bounding it upon tlie south, a small range of granite from 

 Johnsburgh extends into Minerva. It is that variety which decomposes and forms the porcelain 

 clay, already described under Warren county, a few beds of which have been discovered in 

 connection with it. Granite forms a few inconsiderable cliffs in the south part of Elizabeth- 

 town. In Chesterfield, a mile and a half or two miles from Clintonville, in a southerly 

 direction, the common gi-ey granite appears in a high cliff resting upon primary limestone ; 

 and the line of junction between the two rocks, though irregular, is very well defined. 



It is probable that this range of granite is the most extensive of any in the county ; and if 

 so, it passes through the high broken range of mountains in Chesterfield, which could not be 

 explored without the sacrifice of more time than would have been profitable to the survey. 

 The range of rocks between Elizabethtown and Keeseville is an indescribable mixture of 

 granite, hornblende and gneiss, with gi-adations into hypersthcne rock. In exploring some of 

 the upper branches of the Hudson in the midst of the latter rock, a few small masses of flesh- 

 colored granite were found ; and it is highly probable that, in numerous places, it passes into 

 the ordinary forms of granite. In fact, sometimes there is proof of it, in the changes which 

 are seen ; and it is not at all remarkable that passages from one kind of rock to another should 

 take place, when wc consider the circumstances under which they have been formed, and 

 the intluences to which they have been exposed. 



Primary Limestone. 



Commencing at the south, we find this rock entering the county in Ticonderoga, and it 

 appears to be an extension of that mass which occurs in the vicinity of Brant lake. It is im- 

 pure at its outcrop on the roadside south of the village, by intermixture with hornblende, 

 pyroxene, quartz, etc., as is often the case with this rock. After crossing a range of gneiss 

 on the west, we come to another belt of limestone more important than the preceding. It is 

 the one in Schroon, already referred to when speaking of the hypersthene rock. This mass 

 appears to be a continuation of that in Johnsburgh and Athol. Hence it pursues a northeast 

 course, provided it be a continuous rock. It terminates on the lake at Port Henry. This 

 range of limestone is distinguished throughout, or as far as I am acquainted with it, for its 

 compound character, being combined or mixed in several proportions with serpentine. In 

 some parts of the rock, the limestone and serpentine are in about equal proportions ; in other 

 instances, the limestone predominates, the serpentine gradually disappearing, till only here 

 and there a small granule is discernible, when the limestone becomes nearly a pure rock, or 

 free from intermixture with this substance. Whenever these tw-o substances are commingled 

 in the same mass, it is more free from siliceous minerals either in the form of quartz, 



Geol. 2d Dist. 29 



