172 GEOLOGY OF THE SECOND DISTRICT. 



Geological character of the mountain ranges. 



I may now speak of the geological character of the mountain ranges. All but the rocks of 

 the extreme northwestern angle of the county are gneiss in the main, or this appears as the 

 predominant rock ; subject, it is true, to interruption, for limited spaces. Granite, primitive 

 limestone and serpentine appear as intertruded rocks. Upon the east, the Tongue mountain, 

 running down between Lake George and the southern extremity of Lake Ghamplain, is clearly 

 gneiss. The French and Luzerne mountains are gneiss, with some granite and hornblende. 

 The range of which Crane's mountain forms a conspicuous part, is gneiss, with granite of a 

 decomposing kind at its base ; while the entire northwest angle is composed of hypersthene 

 rock, forming as it were a flank to the great central chain which extends from Little-Falls to 

 Trembleau point on Lake Ghamplain. 



In all these ranges the general dip of the strata is westerly, and they strike obliquely across 

 the main axis of the range, in a direction more easterly than that of the chain. 



In the gneiss of these several ranges, there are no characters so peculiar as to require 

 remark, it is all of the ordinary kind, with the same intermixture of hornblende that is com- 

 mon to this rock in other sections of the State. 



The same remark may be made as it regards its imbedded minerals ; there is, in fact, a 

 want of them, especially those of an interesting or useful kind. Imperfect crystals of horn- 

 blende and garnet are not uncommon. It is rather an interesting fact, however, that mica 

 slate does not make its appearance in any of these ranges. It might probably be too much to 

 say that occasional layers may not be found which would pass for this rock ; still, generally 

 speaking, it forms no part of the rocks of Warren or of the other counties of the Second dis- 

 trict. We have, therefore, the parallel fact that minerals peculiar to mica slate are not found 

 at all, as staurotide, kyanite, and but very small quantities of garnet. 



But primitive rocks are rarely entirely destitute of mineral substances, and so we find it 

 here : iron appears to take the place of all others, either in the form of veins, strings, or 

 smaller imbedded masses. Iron ore of the magnetic kind is not unfrequent, but it does not 

 occur in considerable masses. The largest and most important vein is that known as the one 

 owned by Mr. Roberts of Caldwell, which is on lot No. 80, Hyde township. At the surface 

 it is four feet wide, and increases in thickness in its descent into the rock. Other veins exist 

 in Athol, Luzerne township. No. 16, and in the Brant lake tract. Most if not all are veins of 

 sufficient extent to be worked, and are favorably located as it regards wood and water, but 

 unfavorable as it regards transportation to a market. The most important facts relating to 

 the occurrence of veins of ore will be given when the subject is reached under Essex county. 

 The veins of Warren county, though they possess a local importance, yet they do not furnish 

 liiat variety for illustrating the laws of connection between the rock and themselves, as those 

 of the adjoining county. 



