﻿Mansome 
  — 
  New 
  Occurrence 
  of 
  Nepheline 
  Syenite. 
  

  

  Chemical 
  Analyses. 
  

  

  I. 
  II. 
  III. 
  

  

  SiO^ 
  _. 
  54-68 
  59-01 
  53-56 
  

  

  TiO, 
  -79 
  -81 
  

  

  Al^O^ 
  21-63 
  18-18 
  24-43 
  

  

  Fe^Og 
  ._ 
  2-22 
  1-63 
  2-19 
  

  

  FeO 
  2-00 
  3-65 
  1-22 
  

  

  MnO 
  trace 
  -03 
  -10 
  

  

  CaO 
  .- 
  2-86 
  2-40 
  1-24 
  

  

  SrO 
  trace 
  

  

  BaO 
  -05 
  -08 
  

  

  MgO 
  1-25 
  1-05 
  -31 
  

  

  LijO 
  - 
  . 
  trace 
  

  

  Kfi 
  4-58 
  5-34 
  9-50 
  

  

  Na,0 
  V-03 
  7-03 
  6-48 
  

  

  Water 
  at 
  100° 
  C. 
  .. 
  -27 
  -15 
  ) 
  

  

  " 
  above 
  100° 
  C. 
  .. 
  1-88 
  -50 
  f 
  ^^ 
  

  

  CI 
  -- 
  none 
  

  

  F 
  -22 
  

  

  SO3 
  -07 
  

  

  00, 
  none 
  -12 
  

  

  P,0^-. 
  -28 
  trace 
  

  

  99-81 
  99-98 
  99-96 
  

  

  Less 
  O 
  -09 
  

  

  423 
  

  

  99-72 
  

   I. 
  Nepheline 
  syenite 
  from 
  Brookv\lle, 
  N. 
  J. 
  Geo. 
  Steiger, 
  

  

  analyst. 
  

   II. 
  Nepheline 
  syenite 
  from 
  Red 
  Hill, 
  Moultonboro, 
  isT. 
  H. 
  

   Described 
  by 
  Bayley, 
  Bull. 
  Geol. 
  Soc. 
  Am., 
  vol. 
  iii, 
  p. 
  231. 
  

   W. 
  F. 
  Hillebrand, 
  analyst. 
  

   III. 
  Nepheline 
  syenite 
  from 
  Beemerville, 
  N. 
  J., 
  Bull. 
  148, 
  U. 
  S. 
  

   Geol. 
  Surv., 
  p. 
  80. 
  L. 
  G. 
  Kakins, 
  analyst. 
  

  

  Mica 
  Syenite. 
  — 
  This 
  is 
  a 
  gray, 
  medium 
  granular 
  rock 
  which 
  

   has 
  been 
  described 
  as 
  occurring 
  at 
  the 
  fork 
  of 
  the 
  Brook, 
  close 
  

   to 
  the 
  nepheline 
  syenite. 
  The 
  hand-specimens 
  show 
  abundant 
  

   biotite, 
  apparently 
  some 
  amphibole 
  or 
  pyroxene, 
  and 
  both 
  

   white 
  and 
  pinkish 
  feldspars. 
  The 
  pinkish 
  feldspar 
  is 
  some- 
  

   what 
  unevenly 
  distributed 
  and 
  shows 
  a 
  tendency 
  to 
  gather 
  in 
  

   small, 
  ill-dehned, 
  vein-like 
  segregations 
  or 
  streaks. 
  Under 
  the 
  

   microscope 
  the 
  rock 
  shows 
  a 
  hypidiomorphic-granular 
  structure 
  

   and 
  is 
  seen 
  to 
  consist 
  of 
  alkali-feldspar>biotite>pale 
  green 
  

   diopside-like 
  pyroxene. 
  The 
  accessory 
  minerals 
  are 
  apatite 
  

   and 
  iron 
  ore. 
  There 
  is 
  also 
  considerable 
  secondary 
  chlorite, 
  

   calcite, 
  and 
  sericite. 
  The 
  feldspars 
  are 
  generally 
  turbid 
  and 
  

   partly 
  decomposed 
  to 
  sericitic 
  aggregates. 
  They 
  show 
  the 
  

   irregular 
  mottling 
  and 
  fine 
  indefinite 
  twinning 
  common 
  in 
  the 
  

  

  