﻿538 
  . 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  silicates 
  is 
  met 
  but 
  still 
  a 
  quite 
  acid 
  rock 
  (spec. 
  102A), 
  no. 
  115 
  

   near 
  Sabbathday 
  Point, 
  and 
  no. 
  117 
  at 
  Davis 
  bay 
  are 
  similar; 
  no. 
  

   115 
  is 
  a 
  fairly 
  massive 
  binary 
  granite. 
  

  

  At 
  Sabbathday 
  Point 
  a 
  somewhat 
  sheared 
  dark 
  porphyritic 
  

   rock 
  is 
  met, 
  similar 
  to 
  varieties 
  collected 
  in 
  several 
  localities 
  in 
  

   Essex 
  co. 
  It 
  consists 
  in 
  fresh 
  specimens 
  of 
  a 
  dark 
  green 
  

   groundmass 
  of 
  augite 
  which 
  is 
  emerald 
  green 
  in 
  thin 
  section. 
  

   In 
  this 
  aggregate 
  are 
  set 
  large 
  greenish 
  crystals 
  of 
  plagioclase, 
  

   now 
  kaolinized. 
  There 
  is 
  much 
  apatite 
  and 
  much 
  titanite 
  also 
  

   present. 
  If 
  shearing 
  effects 
  this 
  rock 
  the 
  feldspars 
  become 
  len- 
  

   ticular 
  and 
  the 
  dark 
  silicate 
  is 
  drawn 
  out 
  into 
  marked 
  foliation. 
  

   No. 
  109 
  west 
  of 
  Sabbathday 
  Point 
  on 
  Bloomer 
  mountain 
  is 
  the 
  

   same 
  rock. 
  

  

  A 
  third 
  type 
  of 
  gneiss 
  is 
  the 
  green 
  rock 
  which 
  was 
  specially 
  

   described 
  at 
  Whitehall 
  and 
  which 
  has 
  been 
  called 
  the 
  Whitehall 
  

   type. 
  It 
  has 
  been 
  already 
  often 
  referred 
  to 
  as 
  augite-syenite 
  

   gneiss. 
  Hague 
  contains 
  both 
  very 
  basic 
  and 
  very 
  acidic 
  varieties. 
  

   The 
  augite-syenite 
  yields 
  on 
  pressure 
  a 
  dark 
  green 
  gneiss, 
  with 
  

   variable 
  amounts 
  of 
  feldspar 
  and 
  augite. 
  It 
  is 
  found 
  at 
  Deer 
  Leap, 
  

   south 
  of 
  Sabbathday 
  Point, 
  specimen 
  103 
  A; 
  at 
  no. 
  110 
  due 
  west 
  of 
  

   Sabbathday 
  Point; 
  at 
  no. 
  116 
  on 
  Vicar's 
  island; 
  and 
  abundantly 
  

   on 
  Tongue 
  mountain 
  in 
  Bolton. 
  It 
  is 
  also 
  in 
  great 
  amount 
  in 
  the 
  

   southwestern 
  portion 
  of 
  the 
  township 
  and 
  along 
  the 
  southern 
  

   border. 
  As 
  already 
  stated 
  we 
  have 
  gathered 
  in 
  former 
  years 
  a 
  

   great 
  deal 
  of 
  it 
  in 
  Ticonderoga 
  just 
  across 
  the 
  border 
  to 
  the 
  north. 
  

   Our 
  observations 
  are 
  however 
  somewhat 
  fragmentary 
  in 
  the 
  in- 
  

   accessible 
  parts 
  of 
  Hague 
  on 
  the 
  southwest 
  and 
  northwest, 
  and 
  

   we 
  feel 
  conservative 
  about 
  making 
  sweeping 
  statements 
  regarding 
  

   them. 
  Along 
  the 
  road 
  from 
  Graphite 
  to 
  Brantlake 
  the 
  rock 
  was 
  

   noted 
  beyond 
  Swede 
  pond. 
  

  

  A 
  fourth 
  type 
  of 
  gneiss 
  results 
  from 
  foliation 
  induced 
  as 
  nearly 
  

   as 
  we 
  can 
  tell 
  on 
  a 
  porphyritic 
  granite 
  of 
  the 
  kind 
  quarried 
  near 
  

   Horicon 
  village, 
  no. 
  128. 
  This 
  was 
  gathered 
  at 
  no. 
  114 
  back 
  of 
  

   Hague 
  village, 
  and 
  is 
  the 
  " 
  Horicon 
  type." 
  

  

  The 
  strike 
  of 
  the 
  gneisses 
  wherever 
  determined 
  has 
  been 
  almost 
  

   without 
  exception, 
  northwest. 
  The 
  dip 
  about 
  Sabbathday 
  Point 
  

   is 
  northeast, 
  near 
  Hague 
  village 
  it 
  is 
  southwest. 
  

  

  