﻿480 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  strike 
  section. 
  (See 
  also 
  pi. 
  6) 
  The 
  dip 
  section 
  is 
  not 
  well 
  shown 
  

   iDut 
  as 
  far 
  as 
  it 
  can 
  be 
  seen 
  corresponds 
  precisely 
  in 
  its 
  nature. 
  

  

  On 
  the 
  whole 
  this 
  locality 
  presents 
  as 
  strong 
  evidence 
  in 
  re- 
  

   gard 
  to 
  the 
  true 
  nature 
  of 
  the 
  syenite 
  as 
  has 
  been 
  found 
  any- 
  

   where. 
  To 
  be 
  sure 
  the 
  syenite 
  here 
  exposed 
  is 
  not 
  continuous 
  at 
  

   the 
  surface 
  with 
  the 
  main 
  body 
  of 
  the 
  rock, 
  but 
  the 
  latter 
  ap- 
  

   pears 
  only 
  a 
  few 
  rods 
  away 
  and 
  the 
  material 
  of 
  the 
  lenses 
  is 
  ab- 
  

   solutely 
  identical 
  with 
  it. 
  

  

  As 
  intimated 
  above, 
  the 
  rock 
  cut 
  by 
  the 
  syenite 
  is 
  of 
  interest 
  

   when 
  compared 
  with 
  that 
  cut 
  at 
  the 
  previously 
  described 
  locali- 
  

   ties. 
  At 
  the 
  first 
  locality, 
  it 
  was 
  a 
  fine 
  grained 
  gneiss, 
  with 
  minor 
  

   limestone, 
  at 
  the 
  second 
  it 
  was 
  limestone, 
  here 
  it 
  is 
  gneiss 
  again 
  

   but 
  quite 
  different 
  from 
  that, 
  of 
  the 
  first 
  locality, 
  being 
  darker 
  

   colored, 
  more 
  varied 
  and 
  in 
  much 
  greater 
  amount. 
  

  

  At 
  the 
  first 
  locality 
  the 
  gneiss 
  was 
  a 
  rather 
  narrow 
  band 
  over- 
  

   laid 
  by 
  heavy 
  limestone 
  but 
  here 
  the 
  gneiss 
  is 
  very 
  thick 
  continu- 
  

   ing 
  for 
  several 
  rods 
  across 
  the 
  strike 
  with 
  no 
  limestone 
  showing, 
  

   though 
  the 
  highly 
  pyroxenic 
  character 
  with 
  some 
  calcareous 
  

   fragments 
  almost 
  if 
  not 
  quite 
  in 
  place 
  make 
  it 
  practically 
  certain 
  

   that 
  this 
  gneiss 
  is 
  also 
  of 
  the 
  limestone 
  formation. 
  

  

  So 
  in 
  addition 
  to 
  the 
  striking 
  phenomena 
  presented 
  by 
  the 
  dif- 
  

   ferent 
  localities 
  singly 
  we 
  have 
  a 
  supplementary, 
  large 
  structural 
  

   feature 
  afforded 
  in 
  the 
  contact 
  of 
  the 
  syenite 
  with 
  different 
  hori- 
  

   zons 
  of 
  the 
  limestone 
  formation. 
  

  

  Taking 
  all 
  of 
  these 
  structural 
  data 
  together 
  they 
  seem 
  sufficient 
  

   to 
  prove 
  beyond 
  doubt 
  that 
  the 
  syenite 
  is 
  a 
  plutonic 
  igneous 
  rock, 
  

   and 
  the 
  petrographic 
  and 
  chemical 
  characteristics 
  of 
  the 
  rock 
  so 
  

   far 
  as 
  they 
  have 
  been 
  investigated 
  are 
  entirely 
  in 
  harmony 
  with 
  

   this 
  view. 
  

  

  While 
  at 
  one 
  time 
  the 
  gneissic 
  structure 
  would 
  have 
  been 
  re- 
  

   garded 
  as 
  positive 
  evidence 
  of 
  sedimentary 
  origin, 
  at 
  the 
  present 
  

   day 
  it 
  is 
  quite 
  unnecessary 
  to 
  advance 
  any 
  argument 
  to 
  prove 
  

   that 
  this 
  is 
  not 
  the 
  case, 
  as 
  such 
  a 
  structure 
  is 
  now 
  known 
  to 
  have 
  

   no 
  necessary 
  connection 
  with 
  bedding 
  and 
  to 
  be 
  quite 
  as 
  common 
  

   in 
  igneous 
  as 
  in 
  sedimentary 
  rocks. 
  As 
  to 
  its 
  origin 
  in 
  the 
  

   present 
  instance, 
  the 
  cataclastic 
  structure 
  which 
  develops 
  to 
  a 
  

  

  