﻿646 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum, 
  

  

  As 
  a 
  general 
  thing 
  the 
  gneiss 
  is 
  quite 
  basic, 
  and 
  has 
  but 
  little 
  

   quartz 
  in 
  these 
  exposures 
  in 
  the 
  south. 
  It 
  is 
  dark 
  and 
  dioritio 
  in 
  

   appearance, 
  but 
  in 
  thin 
  sections 
  the 
  feldspar 
  is 
  found 
  to 
  be 
  

   microperthitic 
  orthoclase. 
  The 
  dark 
  silicate 
  is 
  commonly 
  horn- 
  

   blende, 
  and 
  with 
  it 
  in 
  some 
  is 
  more 
  or 
  less 
  pyroxene. 
  Qinrtz 
  is 
  

   subordinate, 
  but 
  always 
  present 
  in 
  slight 
  amounts. 
  Apatite, 
  

   zircon, 
  magnetite, 
  the 
  usual 
  accessories 
  are 
  present. 
  Good 
  examples 
  

   of 
  crushed 
  and 
  strained 
  crystals 
  are 
  occasionally 
  met. 
  Along 
  the 
  

   highway 
  where 
  specimens 
  333-355 
  were 
  gathered, 
  there 
  is 
  a 
  fine 
  

   fault 
  and 
  crushed 
  strip. 
  Out 
  west 
  of 
  Long 
  Pond 
  there 
  is 
  a 
  very 
  

   light-colored 
  acidic 
  gneiss, 
  precisely 
  like 
  the 
  wall 
  rock 
  of 
  the 
  one 
  

   at 
  Hammond 
  ville, 
  and 
  one 
  of 
  the 
  drill 
  cores 
  cited 
  earlier 
  from 
  

   Mineville. 
  It 
  contains 
  chiefly 
  quartz 
  and 
  plagioclase 
  with 
  which 
  

   a 
  few 
  shreds 
  of 
  a 
  bluish 
  hornblende 
  are 
  associated. 
  

  

  In 
  the 
  northwestern 
  area 
  of 
  gneiss 
  we 
  have 
  at 
  12 
  a 
  pink 
  

   gneiss 
  with 
  biotite, 
  quartz, 
  microcline 
  and 
  orthoclase, 
  but 
  at 
  13 
  

   a 
  gray 
  variety 
  with 
  quartz, 
  plagioclase, 
  orthoclase, 
  abundant 
  

   green 
  pyroxene, 
  and 
  but 
  little 
  hornblende. 
  At 
  the 
  iron 
  mines, 
  

   the 
  wail 
  rock 
  contains 
  hornblende, 
  biotite, 
  plagioclase, 
  a 
  little 
  

   quartz, 
  and 
  magnetite 
  (115). 
  This 
  area 
  forms 
  a 
  high 
  knob, 
  known 
  

   as 
  Buck 
  mountain. 
  The 
  principal 
  elevation 
  is 
  west 
  of 
  the 
  iron 
  

   mines, 
  but 
  a 
  very 
  considerable 
  spur 
  lies 
  to 
  the 
  eastward, 
  the 
  high- 
  

   way 
  near 
  the 
  mines 
  being 
  in 
  a 
  depression. 
  The 
  strike 
  of 
  these 
  

   gneisses 
  is 
  chieliy 
  east 
  and 
  west, 
  and 
  they 
  have 
  a 
  steep, 
  southerly 
  

   dip. 
  They 
  are 
  in 
  bold 
  contrast 
  in 
  this 
  respect 
  to 
  the 
  other 
  areas, 
  

   north 
  and 
  south. 
  

  

  Series 
  II. 
  The 
  crystalline 
  limestone 
  series 
  has 
  its 
  greatest 
  

   development 
  in 
  Ticonderoga. 
  and 
  the 
  adjoining 
  parts 
  of 
  Crown 
  

   Point, 
  so" 
  far 
  as 
  the 
  county 
  has 
  been 
  yet 
  seen. 
  The 
  whole 
  north- 
  

   ern 
  central 
  portion 
  of 
  the 
  former 
  consists 
  of 
  this 
  series. 
  The 
  white 
  

   beds 
  of 
  marble 
  are 
  not 
  of 
  great 
  width 
  or 
  length, 
  as 
  a 
  general 
  thing. 
  

   They 
  are 
  closely 
  involved 
  with 
  dark 
  schists 
  or 
  gneisses 
  that 
  show 
  

   under 
  the 
  microscope, 
  common 
  hornblende, 
  pale 
  green 
  pyroxene, 
  

   occasional 
  biotite, 
  frequently 
  sea 
  polite 
  and 
  subordinate 
  plagioclase. 
  

   These 
  weather 
  readily 
  to 
  rusty 
  exposures, 
  and 
  this, 
  combined 
  

   with 
  the 
  easy 
  erosion 
  of 
  the 
  limestone, 
  makes 
  the 
  topography 
  less 
  

   elevated 
  than 
  it 
  is 
  with 
  the 
  gneisses 
  and 
  anorthosites. 
  Still 
  there 
  

   is 
  a 
  great 
  deal 
  of 
  garnetiferous 
  gneiss 
  also 
  involved 
  in 
  this 
  area, 
  

   and 
  some 
  outcrops 
  that 
  are 
  shown 
  by 
  the 
  thin 
  sections 
  to 
  be 
  

  

  