﻿ADIRONDACK 
  MAGNETIC 
  IRON 
  ORES 
  165 
  

  

  peaks 
  of 
  which 
  the 
  highest 
  is 
  a 
  little 
  over 
  iooo 
  feet. 
  The 
  approach 
  

   from 
  the 
  western 
  side 
  where 
  it 
  falls 
  toward 
  the 
  Bouquet 
  river 
  is 
  

   more 
  gradual. 
  

  

  The 
  mine 
  openings 
  are 
  in 
  the 
  face 
  of 
  a 
  cliff 
  fronting 
  directly 
  on 
  

   the 
  lake 
  just 
  north 
  of 
  the 
  little 
  cove 
  that 
  is 
  locally 
  known 
  as 
  Snake 
  

   Den 
  harbor. 
  They 
  lie 
  about 
  ioo 
  feet 
  above 
  the 
  shore 
  and 
  consist 
  

   of 
  two 
  drifts, 
  10 
  feet 
  or 
  so 
  wide, 
  which 
  follow 
  the 
  ore 
  back 
  into 
  the 
  

   mountain 
  for 
  a 
  short 
  distance. 
  The 
  workings 
  date 
  back 
  over 
  25 
  

   years, 
  as 
  Smock 
  states 
  in 
  his 
  report 
  that 
  no 
  ore 
  had 
  been 
  mined 
  

   for 
  six 
  years 
  previous 
  to 
  his 
  visit. 
  The 
  concentrating 
  works, 
  

   erected 
  on 
  the 
  lake 
  shore 
  below 
  the 
  mine, 
  have 
  fallen 
  into 
  decay 
  or 
  

   have 
  been 
  removed. 
  A 
  magnetic 
  process 
  was 
  employed 
  for 
  sepa- 
  

   rating 
  the 
  magnetite 
  from 
  the 
  gangue. 
  

  

  The 
  main 
  mass 
  of 
  Split 
  Rock 
  mountain 
  consists 
  of 
  light 
  gray 
  

   anorthosite, 
  with 
  local 
  intrusions 
  of 
  gabbro. 
  Both 
  rocks 
  show 
  

   strong 
  crushing 
  effects, 
  the 
  former 
  in 
  the 
  granulation 
  of 
  the 
  labra- 
  

   dorite 
  which 
  constitutes 
  almost 
  the 
  entire 
  mass, 
  and 
  the 
  'latter 
  

   in 
  its 
  markedly 
  gneissoid 
  texture 
  as 
  well 
  as 
  a 
  similar 
  granulation 
  

   of 
  its 
  constituents. 
  Both 
  contain 
  secondary 
  garnet. 
  The 
  gabbro 
  

   in 
  thin 
  section 
  is 
  seen 
  to 
  be 
  mainly 
  composed 
  of 
  augite, 
  hypersthene, 
  

   brown 
  hornblende, 
  garnet 
  and 
  labradorite, 
  with 
  olivine 
  and 
  magne- 
  

   tite 
  in 
  subordinate 
  amount. 
  The 
  hornblende 
  is 
  plainly 
  a 
  result 
  

   of 
  chemical 
  reaction 
  between 
  the 
  magnetite 
  and 
  the 
  feldspar 
  

   brought 
  about 
  by 
  the 
  dynamic 
  metamorphism 
  which 
  the 
  rock 
  has 
  

   undergone. 
  An 
  analysis 
  of 
  the 
  gabbro 
  quoted 
  from 
  the 
  paper 
  

   by 
  Professor 
  Kemp 
  is 
  given 
  on 
  page 
  148 
  of 
  this 
  report. 
  

  

  The 
  deposits 
  occur 
  directly 
  in 
  gabbro 
  of 
  which 
  there 
  is 
  a 
  consid- 
  

   erable 
  area 
  in 
  the 
  vicinity. 
  The 
  relation 
  between 
  the 
  ore 
  and 
  wall 
  

   rock 
  is 
  that 
  of 
  complete 
  gradation, 
  there 
  being 
  no 
  line 
  of 
  demarca- 
  

   tion 
  whatever 
  between 
  the 
  one 
  and 
  the 
  other. 
  The 
  magnetite 
  in 
  

   the 
  gabbro 
  increases 
  in 
  proportion 
  until 
  it 
  becomes 
  the 
  principal 
  

   constituent; 
  while 
  there 
  is 
  a 
  corresponding 
  retreat 
  of 
  the 
  silicates, 
  

   the 
  feldspar 
  being 
  the 
  first 
  to 
  disappear. 
  A 
  peculiar 
  feature 
  re- 
  

   vealed 
  by 
  examining 
  thin 
  sections 
  is 
  the 
  occurrence 
  of 
  veinlets 
  of 
  

   magnetite 
  that 
  evidently 
  are 
  the 
  fillings 
  of 
  rifts 
  in 
  the 
  ore 
  subse- 
  

   quent 
  to 
  its 
  consolidation. 
  The 
  veinlets 
  are 
  minute, 
  but 
  they 
  can 
  

   be 
  traced 
  generally 
  across 
  the 
  whole 
  section, 
  breaking 
  through 
  

   the 
  silicate 
  minerals 
  as 
  well 
  as 
  the 
  inclosing 
  magnetite. 
  It 
  would 
  

   appear 
  that 
  there 
  must 
  have 
  been 
  a 
  secondary 
  infiltration 
  of 
  magne- 
  

   tite, 
  perhaps 
  from 
  a 
  fused 
  portion 
  of 
  the 
  body 
  at 
  depth. 
  Another 
  

   singular 
  phenomenon, 
  noted 
  by 
  Professor 
  Kemp 
  in 
  the 
  ore 
  from 
  

  

  