ElvISHA MlTCHElvI. SClENTIi^IC SOCIETY. 29 



rocks; and the more irreg-ular outlines would naturally 

 have been produced by larger intrusions accompanied 

 or preceded by intense folding- and contorsion of the 

 gneisses. Furthermore, both the irregular and the 

 more typical lenticular outcrops frequently present a 

 forked outline or send off small apophyses into the 

 gneiss in such a way as would be wholly inexplicable 

 in a rock of sedimentary origin. Prominent examples 

 of this character are presented on the maps of Buck 

 Creek, Corundum Hill and Webster areas (Plates II, 

 III, and IV). A forked mass is found on the mountain 

 slopes at the head of Elijay creek, Macon county, N. 

 C, and a larger one on the spurs of Klk Ridge, in Ashe 

 county. Several others of a similar nature might be 

 added from North Carolina alone. 



The planes of least resistance in gneiss lie along the 

 lamination, and hence, as stated above, we should ex- 

 pect the axes of intrusive masses to coincide with these 

 planes. This is found to be true in the great major- 

 ity of cases, and the apparent exceptions are doubtful. 

 The gneisses and schists bend closely around the en- 

 closed mass, being only temporarily diverted from their 

 normal course. The axes of the bifurcate masses are 

 also found to follow the same general direction. (See 

 Plate III). 



The last requirement in geotecnic evidence would 

 seem to be fulh^ met by the gneiss area, more than a 

 quarter of a mile long, entirely surrounded by perido- 

 tites, on the northern border of the Webster area. (PI. 

 IV). Indeed, this Webster region alone, though once 

 made the basis of a theory of sedimentary^ origin for 

 the peridotites," affords some of the most conclusive 



* "The Dunite Beds of North Carolina," by A. A. Julian, Proc. 



Nat. Hist. Soc, Boston, XXII, 1882, 141-149. 



