﻿ADIRONDACK 
  MAGNETIC 
  IRON 
  ORES 
  II3 
  

  

  definite 
  angles. 
  The 
  large 
  dike 
  near 
  Slope 
  15 
  is 
  a 
  mica 
  diabase 
  

   containing 
  abundant 
  biotite 
  in 
  the 
  place 
  of 
  augite 
  which 
  is 
  the 
  

   normal 
  ferromagnesian 
  mineral. 
  

  

  Geology 
  of 
  the 
  ore 
  bodies 
  

  

  The 
  ore 
  bodies 
  as 
  previously 
  stated 
  are 
  closely 
  associated 
  with 
  

   the 
  augite 
  gneiss, 
  which 
  is 
  strongly 
  developed 
  throughout 
  the 
  dis- 
  

   trict 
  and 
  belongs 
  to 
  the 
  Saranac 
  formation. 
  So 
  far 
  as 
  the 
  rela- 
  

   tions 
  can 
  be 
  observed 
  in 
  mine 
  workings 
  and 
  outcrops, 
  they 
  

   appear 
  to 
  lie 
  in 
  immediate 
  contact 
  with 
  the 
  gneiss 
  throughout 
  most 
  

   of 
  their 
  extent, 
  the 
  only 
  exceptions 
  being 
  at 
  the 
  Williams 
  and 
  

   Dickson 
  pits 
  (and 
  possibly 
  the 
  Parkhurst 
  mine) 
  where 
  they 
  are 
  

   bordered 
  for 
  some 
  distance 
  by 
  schist. 
  The 
  latter 
  rock 
  is 
  limited 
  

   to 
  small 
  bands 
  included 
  in 
  the 
  augite 
  gneiss. 
  

  

  The 
  bodies 
  consist 
  of 
  parallel 
  zones 
  of 
  the 
  gneiss, 
  in 
  which 
  mag- 
  

   netite, 
  forms 
  a 
  relatively 
  large 
  proportion 
  of 
  the 
  mass. 
  The 
  zones 
  

   possess 
  a 
  marked 
  persistency 
  along 
  the 
  strike 
  and 
  on 
  the 
  dip, 
  

   which 
  with 
  their 
  small 
  lateral 
  dimensions 
  gives 
  them 
  a 
  prevailing 
  

   tabular 
  shape. 
  In 
  structural 
  arrangement 
  they 
  conform 
  closely 
  

   to 
  the 
  foliation 
  of 
  the 
  gneiss. 
  Their 
  geologic 
  horizon 
  appears 
  to 
  

   be 
  approximately 
  a 
  constant 
  one, 
  as 
  they 
  are 
  alined 
  in 
  a 
  general 
  

   northeast-southwest 
  direction, 
  parallel 
  to 
  the 
  main 
  strike 
  of 
  the 
  

   region. 
  

  

  The 
  borders 
  of 
  the 
  deposits 
  are 
  not 
  sharply 
  defined. 
  Stringers 
  

   and 
  disseminations 
  of 
  magnetite 
  extend 
  into 
  the 
  gneiss 
  for 
  some 
  

   distance, 
  forming 
  zones 
  of 
  lean 
  ore 
  on 
  either 
  side 
  of 
  the 
  main 
  bodies. 
  

   This 
  gradation 
  is, 
  however, 
  a 
  variable 
  feature 
  more 
  evident 
  in 
  some 
  

   places 
  than 
  others. 
  The 
  gneiss 
  itself 
  shows 
  no 
  noteworthy 
  change 
  

   as 
  the 
  ore 
  bodies 
  are 
  approached. 
  

  

  In 
  character 
  the 
  deposits 
  possess 
  much 
  uniformity 
  throughout 
  

   their 
  extent. 
  The 
  present 
  main 
  workings 
  at 
  Lyon 
  Mountain 
  are 
  

   practically 
  continuous 
  along 
  the 
  strike 
  for 
  a 
  distance 
  of 
  4000 
  feet, 
  

   with 
  few 
  variations 
  noticeable 
  in 
  the 
  occurrence 
  or 
  distribution 
  of 
  

   the 
  ore. 
  In 
  this 
  respect 
  they 
  are 
  in 
  contrast 
  with 
  most 
  magnetite 
  

   bodies 
  which 
  have 
  been 
  found 
  to 
  show 
  frequent 
  irregularities, 
  

   specially 
  in 
  form, 
  from 
  place 
  to 
  place. 
  

  

  The 
  ore 
  is 
  a 
  mixture 
  of 
  magnetite 
  and 
  gangue 
  minerals, 
  the 
  latter 
  

   mostly 
  feldspar 
  (orthoclase, 
  microperthite, 
  microcline 
  and 
  oligo- 
  

   clase), 
  augite, 
  hornblende 
  and 
  quartz. 
  The 
  different 
  constituents 
  

   may 
  be 
  intermixed 
  so 
  as 
  to 
  show 
  an 
  even 
  distribution, 
  but 
  more 
  

   frequently 
  perhaps 
  they 
  have 
  a 
  rudely 
  parallel 
  arrangement 
  , 
  that 
  

   simulates 
  the 
  gneissoid 
  structure 
  of 
  the 
  wall 
  rock. 
  This 
  is* 
  par- 
  

  

  