IXTEEilEDIATE CHAKACTEE OF APPALACHIAN GRANITES 7 



together with biotite usually in excess of muscovite, about as often as does 

 biotite alone. Muscovite in at least one locality each, in South Carolina, 

 North Carolina, Virginia, and Maryland, is essentially unaccomjDanied by 

 biotite and occurs alone. In the Stone Mountain granite of Georgia musco- 

 vite gi'eatly exceeds biotite in amount. The preponderance of biotite granites 

 over others in this area is noteworthy, and has been commented on by Kemp^ 

 and others, for the granites occurring in the eastern portion of North 

 America. 



The great preponderance of biotite granites over others in the eastern 

 United States is «hown in the following tabulation-, and diagrammatieally 

 in figure 1 : 



Classification of granites in the eastern United States. 



I. Biotite granite or gneiss. 



II. Biotite-museovite or muscovite-biotite granite or gneiss. 



III. Biotite-hornblende or hornblende-biotite granite or gneiss. 



IV. Hornblende granite. 

 V. Muscovite granite. 



VI. Biotite-epidote granite. 



VII. Epidote granite. 



•Kemp, J. F., Bull. Geol. Soc. America, 1899, Vol. 10, p. 377 et seq. 



^Tabulation is based oliiefly on quarry data, and under eacli state is included 

 every quarry which the writer lias been able to find a record of. The sources of 

 information from whicli the table has been compiled are the Census reports, reports 

 of the States and Federal Geological Surveys on granites, and niimerous papers 

 published in scientific journals. 



^A part of these contain augite with or without hornblende. Annual Report 

 of the State Geologist for 1908. Geol. Survey of New Jersey, 1909, pp. 62-78. 



