﻿148 
  

  

  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  ical 
  examples. 
  No. 
  i 
  relates 
  to 
  the 
  gabbro 
  at 
  the 
  Split 
  Rock 
  mine; 
  

   No. 
  2 
  to 
  gabbro 
  at 
  Lincoln 
  pond; 
  and 
  No. 
  3 
  to 
  anorthosite 
  from 
  

   Mt 
  Marcy. 
  

  

  1 
  . 
  2 
  3 
  

  

  SiO„ 
  

  

  Ti0 
  2 
  . 
  . 
  . 
  . 
  

   Cr 
  2 
  3 
  . 
  . 
  . 
  

   A1 
  2 
  3 
  . 
  . 
  . 
  

   Fe 
  2 
  3 
  . 
  . 
  . 
  

  

  FeO 
  

  

  NiO.CoO 
  

  

  MnO 
  

  

  CaO 
  

  

  SrO 
  

  

  BaO 
  

  

  MgO 
  

  

  K 
  O 
  . 
  . 
  . 
  . 
  

  

  Na 
  2 
  

   Li 
  2 
  0. 
  

   H 
  2 
  0. 
  

  

  PA 
  

  

  co 
  2 
  , 
  

  

  s. 
  . 
  . 
  

  

  47.88 
  

  

  1 
  . 
  20 
  

  

  tr. 
  

  

  18.90 
  

  

  i-39 
  

  

  10.45 
  

  

  .02 
  

  

  .16 
  

  

  8.36 
  

  

  tr. 
  

  

  tr. 
  

  

  7 
  . 
  10 
  

  

  .81 
  

  

  2 
  -75 
  

   tr. 
  

   .61 
  

   . 
  20 
  

  

  tr; 
  

  

  . 
  12 
  

  

  .07 
  

  

  44 
  

  

  77 
  

  

  5 
  

  

  .26 
  

  

  12 
  

  

  .46 
  

  

  4 
  

  

  •63 
  

  

  12 
  

  

  99 
  

  

  

  tr. 
  

  

  

  17 
  

  

  10 
  

  

  20 
  

  

  5 
  

  

  34 
  

  

  

  95 
  

  

  2 
  

  

  47 
  

  

  

  60 
  

  

  

  28 
  

  

  

  37 
  

  

  

  26 
  

  

  54-47 
  

  

  26.45 
  

  

  1.30 
  

  

  .67 
  

  

  10.80 
  

  

  .69 
  

   .92 
  

  

  4-37 
  

   •53 
  

  

  100.02 
  100.75 
  100.20 
  

  

  The 
  Port 
  Leyden 
  ore 
  body 
  on 
  the 
  west 
  side 
  of 
  the 
  Adirondack^ 
  

   seems 
  to 
  be 
  an 
  anomaly 
  among 
  the 
  titaniferous 
  occurrences. 
  The 
  

   wall 
  rock 
  is 
  not 
  a 
  basic 
  variety 
  belonging 
  to 
  the 
  gabbro-anorthosite 
  

   family, 
  but 
  a 
  quartz 
  gneiss 
  with 
  potash 
  feldspars 
  and 
  a 
  small 
  

   quantity 
  of 
  ferromagnesian 
  minerals. 
  Yet 
  it 
  is 
  not 
  unlikely 
  

   that 
  the 
  deposits 
  may 
  represent 
  only 
  an 
  aberrant 
  type 
  of 
  the 
  

   ordinary 
  occurrences. 
  If 
  the 
  country 
  rock 
  is 
  igneous, 
  as 
  is 
  believed, 
  

   it 
  probably 
  belongs 
  to 
  the 
  general 
  series 
  of 
  intrusives 
  that 
  origi- 
  

   nated 
  from 
  a 
  common 
  parent 
  mass. 
  The 
  ultimate 
  source 
  of 
  the 
  

   iron 
  minerals 
  may 
  thus 
  have 
  been 
  the 
  same 
  as 
  those 
  of 
  the 
  gabbros. 
  

  

  In 
  the 
  relations 
  they 
  bear 
  to 
  the 
  inclosing 
  rocks, 
  the 
  ores 
  are 
  

   sharply 
  differentiated 
  from 
  those 
  of 
  the 
  nontitaniferous 
  class 
  

   which 
  occur 
  in 
  the 
  sedimentary 
  gneisses 
  and 
  schists. 
  They 
  are 
  

   themselves 
  only 
  a 
  phase 
  or 
  development 
  of 
  the 
  igneous 
  magma 
  

   from 
  which 
  the 
  walls 
  have 
  been 
  derived 
  — 
  that 
  is 
  they 
  are 
  rocks 
  

  

  