﻿I40 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  In 
  approaching 
  the 
  mines 
  from 
  Oswegatchie, 
  the 
  highway 
  after 
  

   leaving 
  the 
  Oswegatchie 
  river 
  at 
  Fine 
  passes 
  over 
  a 
  belt 
  of 
  horn- 
  

   blendic 
  and 
  micaceous 
  gneisses 
  and 
  schists 
  that 
  continues 
  for 
  a 
  

   mile 
  or 
  more 
  and 
  is 
  then 
  succeeded 
  by 
  a 
  red 
  granitic 
  gneiss 
  with 
  

   porphyritic 
  feldspars. 
  This 
  rock 
  prevails 
  in 
  most 
  of 
  the 
  exposures 
  

   as 
  far 
  as 
  Monterey. 
  Between 
  that 
  locality 
  and 
  the 
  Clifton 
  mines 
  

   the 
  granitic 
  gneiss 
  gives 
  way 
  to 
  a 
  belt 
  of 
  schists 
  and 
  limestones 
  

   having 
  a 
  northeast-southwest 
  trend 
  parallel 
  to 
  their 
  general 
  strike. 
  

   These 
  are 
  the 
  predominant 
  rocks 
  in 
  the 
  vicinity 
  of 
  the 
  ore 
  bodies. 
  

   They 
  seem 
  to 
  have 
  been 
  somewhat 
  broken 
  and 
  disturbed 
  as 
  they 
  

   show 
  sudden 
  changes 
  in 
  dip; 
  the 
  inclination, 
  however, 
  in 
  most 
  

   cases 
  is 
  toward 
  the 
  southeast 
  at 
  angles 
  of 
  15 
  to 
  45 
  . 
  

  

  The 
  openings 
  are 
  located 
  on 
  the 
  sides 
  and. 
  summit 
  of 
  a 
  hill 
  rising 
  

   100 
  feet 
  or 
  a 
  little 
  more 
  above 
  the 
  site 
  of 
  the 
  steel 
  works 
  in 
  the 
  

   adjoining 
  valley. 
  The 
  principal 
  working 
  is 
  an 
  open 
  cut 
  on 
  the 
  

   summit 
  which 
  exposes 
  a 
  vein 
  20 
  feet 
  wide 
  for 
  a 
  distance 
  of 
  about 
  

   500 
  feet. 
  This 
  is 
  known 
  as 
  the 
  Dodge 
  vein. 
  The 
  immediate 
  wall 
  

   rock 
  is 
  a 
  hornblende 
  schist. 
  Bands 
  and 
  fragments 
  of 
  the 
  schist 
  

   interleave 
  the 
  ore, 
  and 
  on 
  the 
  borders 
  the 
  two 
  are 
  intimately 
  mixed. 
  

   The 
  hornblende 
  gangue 
  carrying 
  the 
  magnetite 
  makes 
  an 
  exceed- 
  

   ingly 
  tough 
  material. 
  On 
  the 
  northeast 
  side 
  of 
  the 
  hill 
  the 
  vein 
  

   has 
  been 
  tapped 
  by 
  an 
  adit 
  and 
  in 
  the 
  walls 
  crystalline 
  limestone 
  

   is 
  exposed 
  in 
  what 
  seems 
  to 
  be 
  an 
  included 
  band 
  about 
  5 
  feet 
  thick. 
  

   The 
  southwest 
  continuation 
  of 
  the 
  vein 
  has 
  been 
  explored 
  by 
  a 
  

   shaft 
  that 
  follows 
  the 
  dip 
  for 
  30 
  feet, 
  showing 
  about 
  20 
  feet 
  of 
  ore 
  

   all 
  the 
  way. 
  East 
  of 
  this 
  deposit 
  and 
  higher 
  up 
  in 
  the 
  schists 
  is 
  the 
  

   St 
  Lawrence 
  vein, 
  8 
  feet 
  thick, 
  that 
  has 
  been 
  explored 
  by 
  open 
  

   cutting 
  and 
  by 
  an 
  incline 
  said 
  to 
  be 
  100 
  feet 
  deep. 
  The 
  ore 
  from 
  

   it 
  is 
  very 
  sulfurous, 
  in 
  places 
  almost 
  solid 
  pyrite 
  and 
  pyrrhotite. 
  

   A 
  third 
  vein 
  is 
  known 
  to 
  underlie 
  the 
  Dodge 
  vein, 
  but 
  its 
  width 
  

   and 
  character 
  have 
  not 
  been 
  determined. 
  

  

  The 
  ore 
  found 
  in 
  the 
  different 
  openings 
  varies 
  from 
  a 
  coarse 
  

   and 
  nearly 
  pure 
  magnetite 
  to 
  a 
  fine 
  grained 
  mixture 
  of 
  disseminated 
  

   magnetite 
  and 
  the 
  minerals 
  of 
  the 
  wall 
  rock 
  which 
  are 
  chiefly 
  horn- 
  

   blende, 
  biotite, 
  garnet 
  and 
  quartz. 
  Pyrite 
  is 
  less 
  in 
  evidence 
  in 
  

   the 
  middle 
  of 
  the 
  veins 
  than 
  on 
  the 
  borders. 
  The 
  ore 
  was 
  subjected 
  

   'to 
  heap 
  roasting 
  before 
  it 
  was 
  smelted 
  to 
  reduce 
  the 
  sulfur. 
  The 
  

   analyses 
  that 
  follow 
  are 
  quoted 
  from 
  a 
  paper 
  on 
  the 
  Clifton 
  mines 
  

   by 
  Professor 
  ^illiman. 
  1 
  

  

  I 
  Am. 
  Inst. 
  Min. 
  Eng. 
  Trans. 
  1871-72. 
  1:364. 
  

  

  