﻿GEOLOGY 
  OF 
  WASHINGTON, 
  WARREN 
  COUNTIES, 
  ETC. 
  515 
  

  

  southeast 
  Dresden 
  borders 
  on 
  South 
  bay, 
  which 
  really 
  is 
  the 
  

   natural 
  southern 
  end 
  of 
  Lake 
  Champlain. 
  In 
  the 
  cliffs 
  along 
  the 
  

   east 
  front 
  of 
  Mt 
  Diameter 
  a 
  most 
  impressive 
  and 
  precipitous 
  

   fault-scarp 
  is 
  presented, 
  and 
  indeed 
  the 
  shores 
  of 
  South 
  bay 
  con- 
  

   stitute 
  one 
  of 
  the 
  most 
  striking 
  and 
  instructive 
  areas 
  in 
  the 
  

   Adirondacks. 
  Dresden 
  is 
  very 
  sparsely 
  settled 
  and 
  is 
  mostly 
  wild, 
  

   mountainous 
  woodland, 
  which 
  has 
  been 
  long 
  since 
  cut 
  over 
  by 
  

   the 
  lumbermen. 
  

  

  Series 
  1. 
  The 
  greater 
  part 
  of 
  the 
  town 
  consists 
  of 
  this 
  series 
  

   as 
  presented 
  in 
  the 
  maps 
  accompanying 
  this 
  report, 
  but 
  the 
  rock 
  

   of 
  the 
  larger 
  part 
  of 
  the 
  area 
  departs 
  from 
  the 
  typical 
  gneisses 
  

   as 
  will 
  be 
  shown. 
  All 
  the 
  metamorphic 
  rocks 
  show 
  evidence 
  of 
  

   most 
  intense 
  compression. 
  The 
  foliation 
  is 
  fine 
  yet 
  persistent 
  

   and 
  though 
  the 
  individual 
  laminae 
  may 
  be 
  but 
  a 
  sixteenth 
  of 
  an 
  

   inch 
  thick, 
  they 
  run 
  with 
  great 
  regularity. 
  In 
  the 
  northern 
  

   part 
  of 
  the 
  town, 
  from 
  specimen 
  38 
  north, 
  the 
  gneisses 
  are 
  gran- 
  

   itic 
  in 
  mineralogy, 
  and 
  contain 
  many 
  small 
  garnets. 
  Quartz 
  is 
  

   frequent 
  and 
  biotite 
  is 
  richly 
  developed. 
  Squeezed 
  pegmatites 
  

   may 
  be 
  detected. 
  Again 
  on 
  the 
  shores 
  of 
  South 
  bay 
  and 
  along 
  

   Pike 
  brook, 
  where 
  the 
  latter 
  forms 
  a 
  cascade 
  near 
  its 
  outlet, 
  the 
  

   gneiss 
  is 
  strongly 
  and 
  regularly 
  foliated 
  and 
  makes 
  the 
  impres- 
  

   sion 
  upon 
  the 
  observer 
  of 
  being 
  derived 
  from 
  an 
  original 
  quartzite. 
  

  

  In 
  the 
  central 
  part 
  of 
  the 
  town, 
  north 
  and 
  south 
  of 
  Dresden 
  

   Center, 
  the 
  gneisses 
  are 
  green 
  and 
  of 
  marked 
  eruptive 
  aspect. 
  

   The 
  foliation, 
  although 
  always 
  discernible 
  varies 
  in 
  distinctness. 
  

   The 
  feldspar 
  of 
  the 
  rock 
  has 
  a 
  bright 
  glistening 
  luster 
  on 
  cleavage 
  

   faces 
  and 
  large 
  porphyritic 
  crystals 
  are 
  often 
  noticeable. 
  Some 
  

   of 
  these 
  are 
  striated 
  and 
  are 
  plagioclase, 
  but 
  the 
  major 
  part 
  are 
  

   unstriated 
  orthoclase. 
  Thin 
  sections 
  show 
  the 
  same 
  relative 
  

   amounts 
  of 
  the 
  two 
  and 
  with 
  them 
  are 
  monoclinic 
  and 
  orthorhom- 
  

   bic 
  pyroxene 
  and 
  quartz. 
  The 
  pyroxenes 
  under 
  dynamic 
  stress 
  

   are 
  largely 
  altered 
  to 
  granular 
  garnet. 
  The 
  orthoclase 
  is 
  chiefly 
  

   microperthitic. 
  This 
  is 
  the 
  same 
  rock 
  that 
  is 
  mentioned 
  under 
  

   Putnam 
  as 
  forming 
  the 
  southern 
  prolongation 
  of 
  Mt 
  Defiance, 
  

   and 
  is 
  a 
  variety 
  of 
  the 
  " 
  Whitehall 
  " 
  type. 
  It 
  is 
  really 
  an 
  augite 
  

   syenite, 
  but 
  is 
  a 
  peculiar 
  variety. 
  It 
  may 
  be 
  a 
  member 
  of 
  the 
  

  

  