202 Remarks on the Gold Mines of North Carolina, 



on the geological structure of the gold region : and then on 

 the causes which have heretofore rendered the mines of this 

 region less productive than they will hereafter become, under 

 a different state of things ; concluding with a few general ob- 

 servations growing out of the nature of the subject. 



(A.) Granite is the base of the formations of the gold re- 

 gion of North Carolina. It is constituted of course of crys- 

 tals, and its surface is very irregular. On its more elevated 

 situations, it has been much worn by the action of water in 

 early times, and now lies exposed, at places on the surface of 

 the earth in large masses, some of them round, as on the 

 small mountain four miles south east of Salisbury. In the 

 lower parts of the country, greenstone and greenstone slate 

 are commonly found in beds in the granite. (6.) 



The greenstone and greenstone slate, in respect of struc- 

 ture, differ in two particulars : 1st, In stratification, and 2d, In 

 composition. 



As to stratification. We occasionally find the greenstone 

 distinctly stratified in almost regular parallel strata, which 

 continue for some distance, when they are intercepted by 

 a mass of the same substance, stratified in a different di- 

 rection, (c.) At other places, the greenstone is found in ir- 

 regular masses, showing no inclination to stratification. 



As to composition. The composition of the greenstone 

 and greenstone slate, bears a striking relation to the stratifi- 

 cation. For example, I have noticed at those places where 

 the greenstone is stratified, that the hornblende forms but a 

 small constituent ; while at those places where the greenstone 

 is not stratified, the hornblende is the chief constituent ; and 

 sometimes so much so, as to lose its character of greenstone 

 and to become basaltic hornblende, (d.) 



In looking over the whole of this formation, we have abun- 

 dant evidence to conclude that great derangements have ta- 

 ken place in it since its first construction. The cause and 

 manner of these derangements, whether by earthquakes, by 

 the contraction of the greenstone itself, or, from some other 

 cause, we are left to conjecture. On some future occasion I 

 may- give my ideas on the subject. 



This formation of greenstone is characterized by the exis- 

 tence of veins in it, containing gold and, in this particular, it 

 differs from all others. 



We here find the gold in two different situations. 



I. As a part of the constituents of the veins, and 



