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  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  mines 
  map. 
  The 
  geology 
  of 
  a 
  county 
  ov 
  district 
  gives 
  the 
  clue 
  

   in 
  searching 
  for 
  ore; 
  and 
  its 
  importance 
  can 
  not 
  ibe 
  too 
  strongly 
  

   stated, 
  both 
  as 
  a 
  guide, 
  suggesting 
  exploration, 
  and 
  warning 
  

   against 
  unnecessary 
  and 
  fruitless 
  surveys 
  and 
  wasteful 
  outlays 
  

   of 
  time 
  and 
  money. 
  For 
  example, 
  the 
  magnetites 
  belong 
  to 
  the 
  

   crystalline 
  rock 
  districts, 
  and 
  the 
  search 
  for 
  them 
  in 
  the 
  later, 
  

   sedimentary 
  rocks 
  of 
  the 
  adjacent 
  territory 
  would 
  be 
  a 
  hopeless 
  

   task; 
  or, 
  again, 
  the 
  exploration 
  of 
  the 
  Highlands 
  or 
  Adirondacks, 
  

   for 
  carbonate 
  ores, 
  would 
  be 
  equally 
  unscientific 
  and 
  destitute 
  

   of 
  good 
  results. 
  

  

  The 
  geological 
  formations, 
  which 
  are 
  characterized 
  as 
  definite 
  

   oire 
  horizons, 
  become 
  the 
  basis 
  of 
  a 
  natural 
  arrangement 
  of 
  the 
  

   ore 
  districts 
  of 
  the 
  state. 
  They 
  are 
  well 
  marked 
  geographically 
  

   also. 
  

  

  Following 
  this 
  geologico-geographical 
  arrangement, 
  the 
  groups 
  

   and 
  iron-oire 
  districts 
  are 
  : 
  

  

  1 
  The 
  Highlands 
  of 
  the 
  Hudson. 
  — 
  Magnetic 
  iron 
  ores. 
  

  

  2 
  The 
  Adirondack 
  region, 
  including 
  the 
  lake 
  Ohamplain 
  mines. 
  — 
  

   Magnetic 
  iron 
  ores. 
  

  

  3 
  The 
  hematites 
  of 
  Jefferson 
  and 
  St 
  Lawrence 
  counties. 
  

  

  4 
  The 
  Clinton 
  or 
  fossil 
  ores. 
  

  

  5 
  The 
  limonites 
  of 
  Dutchess 
  and 
  Columbia 
  counties. 
  

  

  6 
  The 
  limonites 
  of 
  Staten 
  Island. 
  

  

  7 
  The 
  carbonate 
  ores 
  of 
  the 
  Hudson 
  river. 
  

  

  A 
  few 
  isolated 
  mines 
  can 
  not 
  be 
  thus 
  classified, 
  as 
  the 
  hematite 
  

   near 
  Canterbury, 
  Orange 
  county, 
  Ackerman's 
  mine 
  near 
  Union- 
  

   ville, 
  Westchester 
  county, 
  the 
  Napanoch 
  and 
  Wawarsing 
  mines, 
  

   in 
  Ulster 
  county, 
  the 
  hematite 
  of 
  Mt 
  Defiance 
  in 
  Ticonderoga, 
  

   and 
  the 
  bog 
  iron 
  ores 
  which 
  are 
  scattered 
  in 
  all 
  of 
  the 
  great 
  

   divisions 
  of 
  the 
  state. 
  The 
  iron 
  sands 
  of 
  the 
  shores 
  of 
  Long 
  

   lalajid 
  are 
  left 
  out, 
  as 
  not 
  properly 
  a 
  natural 
  source 
  oif 
  iron. 
  

  

  MAGNETIC 
  IRON 
  ORES 
  

   The 
  Highlands 
  of 
  the 
  Hudson 
  

  

  Magnetite 
  is 
  one 
  of 
  the 
  common 
  minepals 
  in 
  the 
  crystalline 
  

   rock 
  region 
  of 
  the 
  Highlands. 
  It 
  occurs 
  as 
  an 
  accessory 
  con- 
  

   stituent 
  in 
  the 
  granitic 
  and 
  gneissic 
  strata; 
  and 
  by 
  itself, 
  forms 
  

  

  