INTKUJMIODIATH CUARA("1'EU OF APPALACHIAN GliANlTES 



33 



Under the old sj'stem of classification, following Lindgren', it is a granite, 

 and the only one of the nine that would be so classified. 



Lewis- has computed tlie position of the rocks corresponding to the 

 analyses in table N in the quantitative classification of igneous rocks. The 

 results may be tabulated as follows : 



Granites of New Jersey. 



Of these II, III, IV, and VI are sodipotassic ; V, VIII, and IX are 



dosodic ; I is between dopotassic and sodipotassic ; and VII is dopotassic. 



GRANITES OF THE WESTEEN IJdSTITED STATES. 



Tliirty analyses^ of granites from the western United States, California 

 (7), Colorado (6), Idaho (3), Michigan (3), Minnesota (3), Missouri (2), 

 Montana (4), and Wisconsin (3), show the following ranges and average in 

 silica, lime, soda, and potash : 



These analyses correspond to the following ranges and average in norma- 

 tive feldspar: 



'Lindgren, W. Op. cit., p. 279. 



"Lewis, J. Volney. Op. eit. 1909, pp. 62-81. 



=Clarke, F. W. Analyses of Rocks. Bull. U. S. Geol. Survey, No. 228, 1904, p. 

 375. Washington, H. S. Professional Paper No. 14, U. S. Geol. Survey, 1903, 

 p. 495. 



