﻿ADIRONDACK 
  MAGNETIC 
  IRON 
  ORES 
  6j 
  

  

  soda, 
  but 
  the 
  inference 
  has 
  not 
  yet 
  been 
  corroborated 
  by 
  analysis. 
  

   The 
  augite 
  is, 
  however, 
  a 
  much 
  more 
  characteristic 
  igneous 
  than 
  

   metamorphic 
  mineral, 
  and 
  militates 
  against 
  original 
  sediments 
  as 
  

   the 
  sources 
  of 
  the 
  rocks 
  and 
  ores. 
  The 
  lean 
  ores 
  are 
  mixed 
  with 
  the 
  

   usual 
  minerals 
  of 
  the 
  wall 
  rocks 
  and 
  among 
  these 
  the 
  basic 
  syenite 
  

   is 
  chief. 
  Hornblende 
  and 
  biotite 
  appear 
  and 
  bring 
  down 
  the 
  per- 
  

   centage 
  of 
  iron. 
  The 
  Old 
  Bed 
  group 
  is 
  pretty 
  sharply 
  marked 
  off 
  

   against 
  the 
  acidic 
  "21 
  " 
  gneiss, 
  the 
  quartz-microperthite 
  aggre- 
  

   gate, 
  but 
  scattered 
  grains 
  of 
  magnetite 
  continue 
  out 
  through 
  the 
  

   latter 
  for 
  many 
  feet. 
  

  

  Anorthosites. 
  This 
  great 
  group 
  of 
  undoubted 
  eruptive 
  rocks 
  is 
  

   specially 
  represented 
  in 
  the 
  western 
  and 
  northern 
  portion 
  of 
  the 
  

   area. 
  Its 
  typical 
  representatives 
  consist 
  almost 
  entirely 
  of 
  labra- 
  

   dorite 
  which 
  may 
  be 
  very 
  coarsely 
  crystalline, 
  still 
  there 
  are 
  always 
  

   minor 
  amounts 
  of 
  augite 
  and 
  titaniferous 
  magnetite 
  and 
  often 
  

   hypersthene 
  associated 
  with 
  the 
  feldspar. 
  The 
  dark 
  silicates 
  some- 
  

   times 
  become 
  relatively 
  abundant 
  and 
  lead 
  to 
  much 
  variation 
  in 
  

   the 
  rocks. 
  At 
  least 
  one 
  distinctive 
  eruptive 
  mass 
  is 
  known, 
  charac- 
  

   terized 
  by 
  relatively 
  large 
  amounts 
  of 
  them 
  and 
  later 
  than 
  the 
  

   main 
  anorthosites. 
  At 
  the 
  headwaters 
  of 
  the 
  Hudson 
  the 
  anor- 
  

   thosites 
  contain 
  the 
  large 
  bodies 
  of 
  titaniferous 
  magnetite, 
  else- 
  

   where 
  described 
  in 
  this 
  bulletin, 
  but 
  they 
  are 
  not 
  known 
  to 
  carry 
  

   ores 
  anywhere 
  in 
  the 
  vicinity 
  of 
  Port 
  Henry. 
  The 
  known 
  titan- 
  

   iferous 
  masses 
  of 
  this 
  region 
  are 
  all 
  in 
  the 
  basic 
  gabbros. 
  

  

  Grenville 
  series. 
  Under 
  this 
  name 
  it 
  has 
  been 
  agreed 
  between 
  

   Canadian 
  and 
  American 
  geologists 
  to 
  describe 
  the 
  undoubted 
  

   metamorphosed 
  sediments. 
  They 
  constitute 
  an 
  important 
  belt 
  

   underneath 
  Port 
  Henry 
  and 
  for 
  3 
  miles 
  or 
  more 
  north. 
  They 
  

   appear 
  also 
  west 
  of 
  Moriah 
  Corners 
  and 
  well 
  over 
  to 
  the 
  foothills 
  

   of 
  the 
  bounding 
  mountains 
  on 
  the 
  west. 
  The 
  most 
  easily 
  recog- 
  

   nized 
  of 
  these 
  rocks 
  is 
  a 
  coarsely 
  crystalline 
  white 
  limestone, 
  with 
  

   graphite 
  and 
  many 
  bunches 
  of 
  included 
  silicates. 
  There 
  is 
  less 
  

   often 
  a 
  serpentinous 
  variety 
  or 
  ophicalcite 
  and 
  with 
  these 
  are 
  rusty 
  

   quartz 
  schists, 
  mica 
  schists, 
  hornblende 
  schists 
  and 
  thinly 
  foliated 
  

   gneisses. 
  While 
  there 
  has 
  been 
  in 
  the 
  past 
  a 
  disposition 
  to 
  class 
  

   with 
  these 
  the 
  more 
  massive 
  gneisses 
  yet 
  it 
  has 
  been 
  a 
  growing 
  

   belief 
  as 
  set 
  forth 
  above 
  that 
  the 
  latter 
  really 
  represent 
  the 
  syenitic 
  

   series 
  of 
  eruptives. 
  The 
  limestones 
  and 
  their 
  included 
  bands 
  of 
  

   silicates 
  are 
  mashed 
  and 
  folded 
  in 
  many 
  complex 
  and 
  involved 
  

   curves, 
  some 
  of 
  which 
  are 
  curiously 
  and 
  strikingly 
  suggestive 
  of 
  

   snakes 
  and 
  other 
  organic 
  forms. 
  The 
  sedimentary 
  metamorphic 
  

   rocks 
  may 
  possibly 
  contain 
  some 
  ore 
  bodies. 
  The 
  Lee 
  bed 
  of 
  sul- 
  

  

  