﻿Report 
  of 
  the 
  State 
  Geologist, 
  647 
  

  

  indistinguishable 
  from, 
  the 
  older 
  series. 
  The 
  outcrops 
  were, 
  how- 
  

   ever, 
  so 
  involved, 
  that 
  on 
  a 
  map 
  of 
  this 
  scale 
  they 
  could 
  not 
  be 
  

   distinguished 
  in 
  the 
  drawing 
  without 
  undue 
  confusion. 
  There 
  is 
  

   a 
  great 
  deal 
  of 
  pegmatite 
  in 
  the 
  form 
  of 
  granitic 
  veins 
  in 
  this 
  

   series 
  II, 
  and 
  the 
  veins 
  are 
  often 
  met 
  throughout 
  the 
  area 
  and 
  

   are 
  quite 
  characteristic. 
  They 
  show, 
  in 
  their 
  section, 
  beautiful 
  

   microcline, 
  plagioclase 
  and 
  quartz. 
  The 
  famous 
  graphite 
  mine 
  

   that 
  has 
  made 
  this 
  town 
  a 
  well-known 
  source 
  of 
  this 
  mineral 
  is 
  

   on 
  a 
  vein 
  of 
  this 
  character. 
  It 
  is 
  situated 
  at 
  121, 
  about 
  three 
  

   miles 
  northwest 
  of 
  Ticonderoga 
  village 
  on 
  Chilson 
  hill. 
  It 
  is 
  a 
  

   true 
  fissure 
  vein 
  that 
  cuts 
  the 
  lamination 
  of 
  the 
  gneiss 
  walls 
  at 
  

   nearly 
  right 
  angles. 
  The 
  wall 
  rock 
  is 
  a 
  garnetiferous 
  gneiss, 
  with 
  

   an 
  east 
  and 
  west 
  strike, 
  and 
  the 
  vein 
  runs 
  at 
  the 
  "big 
  mine" 
  

   north 
  twelve 
  degrees 
  west 
  and 
  dips 
  fifty-five 
  degrees 
  west. 
  There 
  

   are 
  two 
  principal 
  openings, 
  the 
  "big 
  mine" 
  so-called 
  at 
  121, 
  and 
  

   the 
  "little 
  mountain" 
  workings 
  at 
  122, 
  and 
  many 
  smaller 
  ones, 
  

   but 
  all 
  have 
  been 
  long 
  abandoned. 
  The 
  vein 
  filling 
  was 
  evidently 
  

   orthoclase 
  (or 
  microcline) 
  quartz 
  and 
  biotite, 
  with 
  pockets 
  of 
  

   calcite. 
  Besides 
  the 
  graphite, 
  it 
  contained 
  tourmalme, 
  apatite 
  in 
  

   fine 
  prisms, 
  pyrite, 
  and 
  sphene. 
  F. 
  L. 
  Eason 
  has 
  also 
  recorded 
  

   enormous 
  crystals 
  of 
  pyroxene. 
  (Bull. 
  4, 
  N. 
  Y. 
  State 
  Museum, 
  

   p. 
  12, 
  1888.) 
  The 
  graphite 
  must 
  have 
  reached 
  the 
  fissure 
  as 
  some 
  

   volatile 
  or 
  liquid 
  hydrocarbon, 
  such 
  as 
  petroleum, 
  and 
  have 
  

   become 
  metamorphosed 
  in 
  time 
  to 
  its 
  present 
  state. 
  

  

  A 
  great 
  pegmatite 
  vein 
  occurs 
  in 
  the 
  rocky 
  cliff, 
  a 
  little 
  way 
  

   northwest 
  of 
  the 
  steamboat 
  landing 
  at 
  Delano. 
  It 
  is 
  just 
  west 
  of 
  

   a 
  high 
  fence 
  that 
  protects 
  the 
  roadway 
  from 
  the 
  cars. 
  In 
  certain 
  

   portions 
  it 
  is 
  abundantly 
  charged 
  with 
  allanite. 
  

  

  Brecciated 
  gneiss 
  of 
  great 
  perfection 
  occurs 
  in 
  the 
  northwestern 
  

   portion 
  of 
  this 
  area 
  at 
  387 
  and 
  389. 
  

  

  Series 
  III. 
  Thegabbros 
  are 
  represented, 
  so 
  far 
  as 
  yet 
  discovered, 
  

   by 
  three 
  small 
  outliers, 
  but 
  there 
  are 
  doubtless 
  others 
  which 
  may 
  

   be 
  noted 
  hereafter. 
  The 
  one 
  near 
  the 
  town, 
  at 
  365, 
  is 
  a 
  typical 
  

   gabbro, 
  of 
  massive 
  habit. 
  It 
  contains 
  labradorite 
  with 
  abundant 
  

   inclusions 
  at 
  the 
  centers 
  of 
  the 
  crystals, 
  faint 
  green 
  monoclinic 
  

   pyroxene, 
  a 
  little 
  brown 
  hornblende 
  and 
  biotite 
  as 
  runs 
  around 
  

   magnetite, 
  dodecahedral 
  and 
  irregular 
  garnet, 
  which 
  at 
  times 
  

   replaces 
  the 
  twin 
  lamellge 
  of 
  the 
  labradorite. 
  The 
  area 
  in 
  the 
  

  

  