GRANITES OF NORTH CAROLINA 391 



in the sections, oftentimes in nearly equal proportions, though the 

 microcline is subject to considerable variation. Simultaneous crys- 

 tallization of the quartz and a part of the feldspar is usually indicated 

 in the distributed areas of micrographic intergrowths of the two 

 minerals and in the development of micropoikilitic structure in some 

 of the feldspars, the inclusions consisting largely of quartz and plagio- 

 clase. The usual accessory minerals common to granite are noted 

 in the thin sections of the rocks. 



The porphyritic granites have been previously described on p. 378, 

 and it is only necessary here to again emphasize the fact that they 

 are in every case biotite-bearing without hornblende, and are the 

 equivalents in mineral composition of the even-granular granites. 

 Three areas, representing different types of the normal granites, are 

 separately described below. These are: the Dunn's Mountain area 

 in Rowan county; the Mooresville area in Iredell county; and the 

 occurrence of hornblende granite in Mecklenburg county to the 

 north and the south of Charlotte. 



LITHOLOGICAL CHARACTERS. 



The Dunn's Mountain area. — This is a granite ridge twelve to 

 fourteen miles long, having a general northeast- southwest trend and 

 located a few miles southeast of Salisbury. Numerous quarries have 

 been worked over many parts of the ridge which afford excellent 

 opportunity for obtaining fresh specimens of the rock. Two distinct 

 types of the rock are recognized; (a) a very light gray, nearly white, 

 and (&) a pronounced pink. The two are intimately associated. 

 They have the same mineral composition and texture, and. are appar- 

 ently phases or differently colored portions of the same rock-mass. 

 The texture is medium even-granular and is fairly uniform. Dynamic 

 metamorphism has manifested itself over all parts of the ridge in a 

 faintly marked schistose structure, and on the Josey-Bogers places 

 three miles southwest of the village of Faith the rock is completely 

 thinly schistose. Over the north slope of Dunn's Mountain proper 

 pronounced shear zones of the crushed and laminated rock, narrow 

 in width, are developed in the granite mass, striking N. 55°-7o° E. 

 The rock surfaces are slickensided, accompanied by considerable 

 epidotization. 



