Remarks on the Gold Mines of North Carolina. 203 



II. As an ingredient in the alluvial spots of ground in the 

 ranges of this greenstone formation. 



I. In veins. Before I give a particular description of the 

 veins containing gold, it may be proper to give a short ac- 

 count of veins in general, (e.) 



Veins, in general, are fissures in rocks, which were occa- 

 sioned by the contraction of the original mass from its soft 

 state, to a harder, or as some say, by earthquakes. These 

 veins, at one time were open, and were subsequently filled by 

 other materials than the rocks, or substances in which they 

 are situated. Hence, from this it is clear, that different veins 

 in the same formation of rocks may not only be of different 

 ages, but may be made up of different materials ; while veins 

 of the same age in the same formation of rocks always very 

 much resemble each other in their composition. 



For this reason, in all mining countries, where the mineral 

 is found in veins, whenever a new vein is discovered, it be- 

 comes an important point to ascertain whether the new vein 

 is of the same formation as that of any vein before known. 

 After ascertaining this, an estimate may be formed of the 

 richness or poverty of the new vein from analogy with the 

 others. 



Experience has also taught, that we may form a pretty cor- 

 rect idea of the extent of a vein, in length and depth, from its 

 thickness on the surface. (/.) 



The last remark I shall make on this part of the subject is, 

 that a vein cannot extend farther than the depth of the form- 

 ation of rocks in which it is situated, but must terminate there. 

 Hence it is highly necessary, in mining, to know the depth of 

 the general formation at the place where you wish to operate. 



These general remarks were necessary to a correct under- 

 standing of the veins in the greenstone formation embracing 

 the gold region of North Carolina. 



On a former occasion, I remarked, that the veins of the 

 greenstone now in question are distinguishable into three 

 formations, as well on account of their age as in other par- 

 ticulars. I will extend the view I then took of the subject. 



The oldest formation of veins, pertains more particularly 

 to the south west part of the gold region. The thickness of 

 these veins is from two to four feet ; their extension in length 

 is known already to exceed a mile. This gives assurance that 

 they sink to a considerable depth. Their general direction 

 is east and west, dipping occasionally 40° to 50° North. — 



