﻿310 
  W. 
  Lindgren 
  — 
  Granitic 
  Rocks 
  of 
  California. 
  

  

  Per 
  Cent. 
  

  

  Si0 
  2 
  11-48 
  

  

  A1 
  2 
  3 
  3-27 
  

  

  K 
  2 
  3- 
  

  

  KAlSi 
  3 
  8 
  17-75 
  

  

  SiO, 
  2020 
  

  

  Al 
  o 
  3 
  5-74 
  

  

  Na 
  2 
  3-47 
  

  

  NaAlSi 
  3 
  8 
  29-41 
  

  

  Si0 
  o 
  5-14 
  

  

  A1 
  2 
  3 
  4-37 
  

  

  CaO 
  _ 
  2-40 
  

  

  CaAl 
  2 
  Si 
  2 
  8 
  11-91 
  

  

  SiO„... 
  -42 
  

  

  TiO" 
  2 
  .„ 
  -58 
  

  

  CaO 
  -40 
  

  

  Titanite 
  1-40 
  

  

  PA 
  -- 
  '12 
  

  

  CaO 
  -16 
  

  

  CI 
  -02 
  

  

  Apatite 
  -30 
  

  

  Magnetite 
  ._ 
  -84 
  

  

  Hornblende 
  and 
  biotite 
  12*79 
  

  

  Quartz 
  25-71 
  

  

  100-11 
  

  

  For 
  the 
  hornblende 
  and 
  biotite 
  there 
  remains 
  : 
  

  

  Si0 
  2 
  (4-50) 
  

  

  A1„0 
  3 
  2-13 
  

  

  Fe" 
  2 
  O 
  a 
  1-13 
  

  

  FeO... 
  2-00 
  

  

  CaO 
  -64 
  

  

  MgO 
  1-10 
  

  

  K 
  2 
  -66 
  

  

  H 
  2 
  -63 
  

  

  12-79 
  

  

  The 
  estimation 
  is 
  made 
  in 
  the 
  following 
  way 
  : 
  A 
  small 
  

   amount 
  of 
  potash 
  and 
  soda 
  being 
  first 
  subtracted 
  for 
  the 
  bio- 
  

  

  