﻿GEOLOGY 
  OF 
  SARATOGA 
  SPRINGS 
  AND 
  VICINITY 
  9 
  

  

  recognizable 
  over 
  a 
  large 
  part 
  of 
  Canada 
  and 
  in 
  the 
  Upper 
  Lake 
  

   region 
  as 
  well 
  as 
  in 
  the 
  Adirondacks. 
  

  

  A 
  much 
  later 
  peneplain, 
  of 
  probable 
  late 
  Mesozoic 
  date, 
  was 
  

   also 
  developed 
  in 
  the 
  region, 
  and 
  again 
  it 
  was 
  merely 
  the 
  local 
  

   development 
  of 
  a 
  peneplain 
  of 
  wide 
  extent 
  in 
  eastern 
  North 
  

   America. 
  Prior 
  to 
  its 
  development, 
  deformation 
  of 
  the 
  region 
  

   had 
  up 
  warped 
  the 
  older 
  peneplain 
  into 
  the 
  form 
  of 
  a 
  gentle 
  dome, 
  

   and 
  at 
  the 
  same 
  time 
  downwarped 
  the 
  margins 
  into 
  shallow 
  troughs 
  

   in 
  which 
  early 
  Paleozoic 
  sandstones, 
  limestones 
  and 
  shales 
  had 
  

   been 
  deposited. 
  The 
  Mesozoic 
  peneplain 
  truncated 
  the 
  domed 
  

   summit 
  of 
  the 
  older 
  peneplain 
  ; 
  but 
  on 
  the 
  margins 
  of 
  the 
  region 
  

   the 
  two 
  surfaces 
  intersect 
  and 
  the 
  older 
  passes 
  beneath 
  the 
  younger. 
  

   The 
  Paleozoic 
  rocks 
  lie 
  upon 
  the 
  surface 
  of 
  the 
  older, 
  and 
  the 
  

   younger 
  cuts 
  across 
  them 
  (figure 
  i). 
  An 
  attempt 
  to 
  illustrate 
  the 
  

   manner 
  in 
  which, 
  by 
  erosional 
  stripping 
  back 
  of 
  the 
  Paleozoic 
  

   cover, 
  portions 
  of 
  the 
  old 
  peneplain 
  surface 
  are 
  exposed 
  to 
  view 
  

   at 
  the 
  margins 
  of 
  the 
  Adirondacks, 
  is 
  seen 
  in 
  figure 
  2. 
  

  

  _b 
  

  

  Mr 
  '^' 
  /x 
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  Fig. 
  1 
  Domed 
  surface 
  of 
  Precambric 
  peneplain, 
  b 
  b 
  b, 
  with 
  marginal 
  

   Paleozoic 
  deposits, 
  both 
  truncated 
  by 
  late 
  Mesozoic 
  peneplain, 
  a 
  a 
  a. 
  Verti- 
  

   cal 
  scale 
  much 
  exaggerated. 
  

  

  Fig. 
  2 
  Diagram 
  in 
  illustration 
  of 
  the 
  manner 
  of 
  reaapearance 
  of 
  the 
  old 
  

   Precambric 
  peneplain 
  at 
  the 
  present 
  surface 
  ; 
  a 
  b 
  — 
  late 
  Mesozoic 
  peneplain 
  ; 
  

   c 
  d 
  = 
  tipped 
  surface 
  of 
  old 
  peneplain, 
  in 
  part 
  covered 
  by 
  Paleozoic 
  rocks; 
  

   from 
  c 
  to 
  c, 
  however, 
  the 
  Paleozoics 
  have 
  been 
  recently 
  removed 
  by 
  erosion, 
  

   reexposing 
  the 
  old 
  peneplain 
  surface; 
  modern 
  erosion 
  has 
  cut 
  valleys 
  in 
  

   both 
  peneplain 
  surfaces, 
  but 
  the 
  ridge 
  summits 
  are 
  remnants 
  of 
  these 
  

   surfaces. 
  

  

  Since 
  the 
  development 
  of 
  the 
  Mesozoic 
  peneplain 
  the 
  highland 
  

   has 
  been 
  again 
  uplifted, 
  the 
  uplift 
  being 
  greatest 
  along 
  the 
  eastern 
  

   border. 
  This 
  has 
  given 
  the 
  peneplain 
  surfaces 
  a 
  tilt 
  to 
  the 
  west. 
  

   Since 
  this 
  uplift 
  the 
  present 
  valleys 
  of 
  the 
  region 
  have 
  been 
  cut 
  

   below 
  the 
  surface 
  of 
  the 
  Mesozoic 
  peneplain 
  and, 
  on 
  belts 
  of 
  weak 
  

   rocks, 
  have 
  become 
  broadly 
  developed. 
  The 
  entire 
  surface 
  of 
  

   the 
  Saratoga 
  and 
  Schuylerville 
  quadrangles 
  is 
  below 
  the 
  level 
  of 
  

   the 
  peneplain, 
  with 
  the 
  possible 
  exception 
  of 
  the 
  hill 
  summits 
  in 
  

  

  