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UNIVERSITY 01* VIRGINIA PUBLICATIONS 



the subrang names^, harzose (1), tonalose (5), yellowstonose (2), and 

 lassenose (3). With only one exception (harzose, which is sodipotassie) 

 they are dosodic rocks. The range in quartz is less than for the quartz 

 dioriteSj being from 11.09 per cent, to 25.3 per cent., with a total average 

 of 20 per cent. 



Granodiorites of Western United States.'' 



SUMMAEY. 



In the tables below are summarized under Southern granites. New Eng- 

 land granites, and Western granites, the range and average in silica, lime, 

 soda, and potash; and the range and average in miaeral constitution of 

 the feldspar. The tabulations are strikingly similar for the three sections. 

 Of the four oxides, under the column of "average" for the three sections, 

 Si02 which is in largest amount, naturally shows the greatest difference, 

 amounting to only 1.52 per cent, between the minimum (Southern granites) 

 71.16 per cent, and the maximum (New England granites) 72.68 per cent., 

 a difference which must be considered very small. Tiie average in SiOj 

 for the New Jersey granites is a fraction of one per cent, higher than for 

 the New England rocks. The difference in range and average of lime 

 (pp. 37 and 38) and the alkalies, Na^O and K^O, for the same areas 

 including New Jersey (p. 31) is scarcely appreciable. 



Variation in the mineral constitiition of the feldspar for the three sec- 

 tions is equally small. The southern granites show the lowest average in 

 silica and the highest average in total feldspar. Tlae New England granites 

 average highest in silica, and average slightly higher in total feldspar than 



'Washington, H. S. Op. cit., 1903. 



-Average of 11 analyses : California ( 9 ) , Washington ( 2 ) 



