240 Geology of North Carolina. 



Prof. O. pronounces the soapsrone of Orange county to be 

 the most elegant he has ever seen. In several places cop- 

 per has been found in connection with it. 



The granular sulphate of barytes, of Lincoln county, is 

 extremely well characterized ; and it very much resembles in 

 appearance srfow white granular carbonate of lime. 



In crossing the strata of the slate formation now described, 

 to the west, we fall in next, as might be anticipated, with 

 older primary rocks, as mica slate, gneiss and granite. This 

 zone of rocks runs across the state in a south western direc- 

 tion, and extends westward to the blue ridge. The Report 

 denominates it the granitic district, using the term granitic 

 in rather a loose and popular sense. The granite lies next to 

 the slate formation : next succeeds the gneiss, and then the 

 mica slate. Beyond this, and occupying about twenty five 

 miles of the western part of the state, lies a formation of ar- 

 gillaceous slate, usually denominated transition. 



A remarkable stratum of gneissoid rock occurs in this con- 

 nection, which is thus described in the Report. 



Columnar Gneiss ? A remarkable structure in Surry, seven 

 miles north of Rockford. It consists of cylindrical masses or col- 

 umns lying northeast and southwest, and exhibiting a striking re- 

 semblance to logs of wood laid side by side. The columns are 

 a foot each in diameter, and where they appear in the bed of a 

 creek, they extend unbroken forty or fifty feet in length. They 

 are seamed cross-wise at short intervals, and the fragments ap- 

 pear like billets of sawn wood. Indeed the whole bears a stri- 

 king resemblance to petrified wood, the laminated structue being 

 not unlike vegetable fibre. These cylinders rest on gneiss of 

 tabular structure, which is susceptible of a division into very 

 large parallelopipeds.— This singular formation is only about 

 three miles broad. The texture is soft and the fragments are 

 used for coarse whet-stones. 



The different varieties of the granite of this district are 

 thus described. 



The vicinity of Salisbury affords an example of the best 

 building granite. Four and a half miles north of the town is a 

 specimen of this kind which is not surpassed by any that I have 

 ever seen. It resembles that of Raleigh, which appears very 

 advantageously in the new projections of the Capitol ; but the 

 Salisbury granite is even superior to that, being more free from 

 veins of a harder, coarser kind of the same rock, and conse- 

 quently more easily dressed than that of Raleigh. Jt very much 



