70 



which, subsequent to the production of the neighbouring rocks, was 

 forcibly injected between them by igneous agencies from beneath, 

 rising in the directions of least resistance, and, therefore, generally, 

 though by no means uniformly, following the places of stratification 

 of the rocks through which they passed. Instead, therefore, of con- 

 sidering them as beds like the adjoining strata, as some writers have 

 done, we would incline to class them among veins of injection, of 

 which numerous instances occur in other parts of the globe. "We 

 are the more persuaded of the correctness of this view of their origin, 

 from the consideration that throughout all the region in which the 

 quartz veins are found, very peculiar modifications in the structure 

 and composition of the surrounding rocks are invariably to be ob- 

 served — modifications for which no adequate cause can be found in 

 the other igneous rocks which occasionally occur. In the Blue 

 Ridge, the South-west mountain, and in numerous other lines, it may 

 always be remarked, that wherever the modified rocks occur, indi- 

 cating an igneous action, more or less intense, which has wrought a 

 change in their structure, and induced new arrangements of the in- 

 gredients of the rocks, heavy veins of quartz are sure to lie in their 

 immediate vicinity; while through the body of the rocks themselves, 

 countless minute veins of the same material are seen diverging from 

 the principal mass, and imparting various metamorphic characters 

 to the substances with which they are in contact. 



Besides the auriferous veins of the region in which gold occurs, 

 there exist many other veins of quartz agreeing with those which 

 have been found productive in nearly all particulars, save that of 

 containing a valuable proportion of the precious metal. It is highly 

 probable that none of these veins are entirely destitute of gold, and 

 in many instances no doubt the prosecution of the vein would lead 

 to the discovery at other points of it, of an ore sufficiently rich to 

 reward the labour of the extraction. Indeed, it must be looked upon 

 as probable, that the auriferous character, more or less, pervades 

 the quartz veins generally, even as far as their western limit in the 

 Blue Ridge. The striking similarity in the character of them all, 

 and the obvious contemporaneousness of their origin, would seem to 

 give great plausibility to this opinion ; and if we are to credit the 

 statements of the discovery of gold in the western part of Albemarle, 

 and at one or two other points equally remote from the gold region, 

 as usually defined, we can no longer doubt the propriety of regard- 

 ing the Blue Ridge as the proper western boundary of the auriferous 



