ELISHA MITCHELL SCIENTIFIC SOCIETY. 79 



schists; all of which are at best inferior for road construc- 

 tion. Here and there, however, trap dykes are found in 

 this belt; and in places the siliceous slates become some- 

 what massive, passing intohornstone and a quartzite, which, 

 when crushed, will answer fairh- well for macadamizino- 

 purposes. In other places the chloritic schists become 

 somewhat massive and tough and can be used in the same 

 way. In still other places, as about the State University, 

 and along the eastern border of Orange countv, the rock 

 is a fine-grained, tough syenite, accompanied by trap 

 dykes, and is eminently suited for road purposes; and again, 

 as near Hillsboro, granite occurs in a limited area. Vein 

 quartz ("white flint") is abundant in many parts of the 

 belt; and, though not usually recommended as road 

 material, is worthy of consideration. While, then, on the 

 whole the rocks of this belt are not suitable for use as road 

 material, yet a careful search will show the existence of a 

 sufficient quantity of material of .fair quality to macadam- 

 ize all the public roads. And should this supply ever 

 prove insufficient, excellent materials are to be found in 

 abundance in the granite belt along the western border of 

 this region, and in the trap dykes of the sandstone on the 

 eastern border. 



The Gneisses and Other Rocks of the Piedmont Counties. 

 — West of the central granite belt as described above, and 

 extending back to the foot-hills of the Blue Ridge, is the 

 region occupied by the Piedmont counties — Rockingham, 

 Stokes, Forsyth, Yadkin, Surry, Wilkes, Davie, Iredell, 

 Alexander, Caldwell, Burke, McDowell, Rutherford, Polk, 

 Cleveland, Catawba, Lincoln and Gaston. The rocks of 

 this region resemble in many respects those of the Raleigh 

 granite belt. They consist of a succession of gneisses, 

 schists and slates, more hornblendic toward the east and 

 more micaceous toward the west, with here and there 

 masses and dykes of syenite, trap and other eruptive rocks. 



