﻿CRYSTALLINE 
  ROCKS 
  OF 
  THE 
  WESTERN 
  ADIRONDACK 
  REGION 
  471> 
  

  

  different 
  places, 
  a 
  fact 
  which 
  falls 
  perfectly 
  into 
  line 
  with 
  the 
  

   other 
  structural 
  data 
  thus 
  far 
  accumulated. 
  

  

  Fig. 
  4 
  Contact 
  of 
  syenite 
  and 
  gneiss 
  series. 
  Length 
  of 
  section 
  one 
  half 
  mile. 
  

  

  A 
  further 
  and 
  even 
  more 
  striking 
  illustration- 
  of 
  the 
  relation 
  

   just 
  brought 
  out 
  appears 
  on 
  the 
  examination 
  of 
  exposures 
  about 
  

   one 
  and 
  one 
  half 
  miles 
  east 
  of 
  the 
  last 
  locality 
  where 
  the 
  road 
  from 
  

   Pitcairn 
  forke 
  to 
  Jayville 
  runs 
  close 
  to 
  Jenny 
  creek. 
  Beside 
  a 
  

   waterfall 
  and 
  dam 
  in 
  the 
  creek 
  there 
  is 
  an 
  excellent 
  exposure 
  of 
  the 
  

   syenite 
  in 
  contact 
  with 
  a 
  fine, 
  well 
  laminated, 
  dark 
  gray 
  gneiss. 
  

   The 
  contact 
  is 
  very 
  sharp 
  and 
  there 
  is 
  no 
  gradation 
  between 
  the 
  

   two 
  rocks 
  though 
  the 
  syenite 
  is 
  as 
  usual 
  gneissoid 
  with 
  foliation 
  

   parallel 
  to 
  that 
  of 
  the 
  fine 
  gneiss. 
  The 
  syenite 
  forms 
  lenses 
  

   elongated 
  in 
  the 
  direction 
  of 
  foliation 
  and 
  also 
  irregular 
  masses 
  

   cutting 
  across 
  the 
  foliation 
  of 
  the 
  gneiss. 
  

  

  The 
  width 
  of 
  the 
  lenses 
  varies 
  greatly 
  as 
  does 
  that 
  of 
  the 
  gneiss 
  

   between 
  adjacent 
  lenses 
  and 
  sharp 
  inclusions 
  of 
  the 
  gneiss 
  occur 
  

   in 
  the 
  syenite. 
  The 
  phenomena 
  are 
  all 
  exhibited 
  with 
  great 
  clear- 
  

   ness 
  in 
  a 
  section 
  parallel 
  to 
  the 
  strike, 
  and 
  after 
  a 
  most 
  careful 
  

  

  

  Fig. 
  5 
  Contact 
  of 
  syenite 
  and 
  fine 
  gray 
  gneiss 
  presumably 
  of 
  the 
  limestone 
  series. 
  The 
  

   section 
  is 
  parallel 
  with 
  the 
  strike 
  and 
  is 
  about 
  25 
  feet 
  in 
  length. 
  

  

  examination 
  the 
  writer 
  found 
  it 
  impossible 
  to 
  arrive 
  at 
  any 
  satis- 
  

   factory 
  explanation 
  other 
  than 
  that 
  of 
  the 
  intrusion 
  of 
  the 
  sye- 
  

   nite 
  into 
  the 
  gneiss. 
  Fig. 
  5 
  is 
  taken 
  from 
  a 
  field 
  diagram 
  of 
  this 
  

  

  