﻿GEOLOGY 
  OF 
  WASHINGTON, 
  WARREN 
  COUNTIES, 
  ETC. 
  

  

  517 
  

  

  On 
  the 
  northwest 
  side 
  of 
  South 
  bay 
  is 
  a 
  dike 
  of 
  gabbro 
  that 
  is 
  

   not 
  indicated 
  on 
  the 
  map 
  except 
  bj 
  the 
  number 
  56. 
  It 
  lies 
  

   at 
  a 
  quite 
  flat 
  angle 
  with 
  a 
  northeast 
  strike 
  and 
  a 
  northwest 
  

   dip. 
  It 
  cuts 
  the 
  foliation 
  of 
  the 
  gneisses 
  at 
  a 
  low 
  angle 
  as 
  shown 
  

   in 
  fig. 
  1. 
  The 
  gneisses 
  strike 
  east 
  and 
  west 
  and 
  dip 
  30 
  N. 
  Where 
  

   the 
  exposure 
  is 
  seen 
  in 
  a 
  steep 
  bluff 
  along 
  the 
  shore, 
  the 
  shore- 
  

   line 
  runs 
  northeast. 
  The 
  dike 
  is 
  broken 
  and 
  thrown 
  a 
  foot 
  or 
  

   two 
  by 
  a 
  normal 
  fault 
  which 
  is 
  diagrammatically 
  shown 
  in 
  the 
  

   cliffs. 
  Another 
  plane 
  of 
  dislocation 
  likewise 
  crosses 
  the 
  dike 
  but 
  

   with 
  an 
  almost 
  imperceptible 
  throw. 
  The 
  faults 
  strike 
  north- 
  

   west 
  and 
  dip 
  southwest. 
  The 
  dike 
  is 
  10 
  feet 
  thick. 
  The 
  rock 
  is 
  

   excessively 
  granulated, 
  all 
  the 
  minerals 
  except 
  the 
  feldspar 
  being 
  

   crushed 
  to 
  fine 
  fragments 
  as 
  is 
  shown 
  in 
  fig. 
  B, 
  of 
  plate 
  5, 
  which 
  

   is 
  inserted 
  under 
  Whitehall. 
  The 
  feldspars 
  have 
  suffered 
  less 
  

   granulation 
  but 
  they 
  have 
  not 
  entirely 
  escaped. 
  

  

  Fig. 
  1 
  

  

  Section 
  of 
  gabbro 
  dike, 
  spec. 
  56, 
  on 
  South 
  bay, 
  Dresden. 
  

  

  A 
  short 
  distance 
  southwest 
  another 
  dark 
  band 
  was 
  noted 
  in 
  

   the 
  gneisses, 
  apparently 
  parallel 
  to 
  their 
  foliation. 
  

  

  Precambrian 
  qwartzite. 
  In 
  Dresden 
  and 
  Whitehall 
  townships 
  

   the 
  writers 
  have 
  met 
  rocks 
  which 
  were 
  considered 
  by 
  them 
  in 
  

   the 
  field 
  to 
  be 
  metamorphosed 
  elastics 
  and 
  probably 
  although 
  

   gneisses 
  now, 
  to 
  have 
  been 
  originally 
  quartzites. 
  It 
  was 
  re- 
  

   marked 
  above 
  that 
  gneisses 
  of 
  this 
  character 
  were 
  present 
  at 
  the 
  

   Cascade 
  of 
  Pike 
  brook, 
  where 
  the 
  foliation, 
  if 
  indeed 
  it 
  be 
  not 
  

   bedding 
  is 
  remarkably 
  perfect. 
  Over 
  the 
  divide 
  from 
  the 
  head- 
  

   waters 
  of 
  Pike 
  brook, 
  and 
  about 
  a 
  mile 
  and 
  a 
  half 
  southwest 
  of 
  

   Dresden 
  Center, 
  Mr 
  Newland 
  recorded 
  a 
  black 
  quartzite 
  on 
  a 
  

  

  