87 



pebbles of felspar and rounded ones of quartz, &c. in a deep red 

 paste. The four last specimens belong to the S. E. slope of the 

 ridge. 



14. A white, rather loose and coarse sandstone, the grains united 

 chiefly by felspar. 



15. A coarse sandstone, with rather angular pebbles of quartz 

 and felspar scattered through a paste very similar to the mass of a 

 greenish chloritic sandstone. 



16. A very light lemon-green epidotic sandstone, with small 

 specks of quartz and veins or patches of asbestos. 



17. A very heterogeneous conglomerate, in aspect somewhat like 

 the Potomac marble, and identical with the conglomerate before de- 

 scribed as occurring in the vicinity of the S. W. mountain, &c. the 

 larger pebbles identical with No. 6. 



18. A compact, close-grained purplish-gray sandstone, greatly 

 altered, having kernels of epidote, and quartz, and deep red blotches, 

 making it look like heliotrope. 



19. Similar to 7, but destitute of the specks. 



20. At the eastern base of the ridge, slaty sandstones of a gray 

 colour. 



In presenting the above account of the series of rocks in this por- 

 tion of the Blue Ridge, I do not wish it to be inferred, that precisely 

 the same beds in the same order will everywhere be found. Ob- 

 servation has shown, that in different parts of the range, the rocks 

 vary somewhat in their character, that while in some places the 

 sandstones are greatly indurated, and filled with various minerals- 

 apparently developed by intense heat ; in others, they are compara- 

 tively unaltered, though in all the localities yet visited, some of the 

 beds exhibit great induration from this cause. We are, however, 

 to take this descriptive list as representing the important peculiari- 

 ties of the rocks of the Blue Ridge, and we have preferred thus de- 

 scribing them in some detail in the order in which they occur, to 

 attempting to name them according to any supposed or fancied 

 analogies they may bear to rocks, which are found in the old world. 

 Such analogies are very vague, and in this as in many other in- 

 stances in the geology of our country, are calculated to give perma- 

 nency to error and check a proper spirit of investigation. In the 

 true spirit of his science, the enlightened geologist has learned to 

 distrust the generalizations which would always seek analogues to 



