﻿GEOLOGY 
  OF 
  SARATOGA 
  SPRINGS 
  AND 
  VICINITY 
  1 
  45 
  

  

  should 
  be 
  also 
  sliced 
  by 
  big 
  normal 
  faults. 
  So 
  far 
  as 
  we 
  know, 
  

   this 
  is 
  not 
  the 
  case. 
  If 
  on 
  the 
  other 
  hand 
  the 
  thrust 
  faulting 
  is 
  

   of 
  a 
  later 
  date 
  than 
  the 
  normal 
  faulting, 
  the 
  overthrust 
  materials 
  

   should 
  rest 
  on 
  a 
  floor 
  composed 
  of 
  the 
  rocks 
  of 
  the 
  western 
  basin, 
  

   these 
  latter 
  cut 
  by 
  normal 
  faults 
  which 
  do 
  not 
  rise 
  into 
  the 
  over- 
  

   lying, 
  overthrust 
  rocks. 
  

  

  We 
  do 
  not 
  as 
  yet 
  possess 
  decisive 
  evidence 
  on 
  these 
  points. 
  Such 
  

   as 
  we 
  do 
  have, 
  however, 
  seems 
  to 
  indicate 
  that, 
  in 
  the 
  Saratoga 
  

   region, 
  the 
  bulk 
  of 
  the 
  thrust 
  faulting 
  is 
  of 
  later 
  date 
  than 
  the 
  

   normal 
  faulting. 
  

  

  Cessation 
  of 
  the 
  continental 
  deposits 
  of 
  early 
  Mesozoic 
  age 
  in 
  

   the 
  eastern 
  troughs 
  was 
  probably 
  brought 
  about 
  by 
  renewed 
  uplift. 
  

   Then 
  followed 
  a 
  long 
  period 
  of 
  erosion 
  whose 
  final 
  result 
  was 
  a 
  

   rather 
  thorough 
  wearing 
  down 
  of 
  the 
  region 
  to 
  a 
  comparatively 
  

   level 
  plain. 
  Such 
  an 
  erosion 
  plain 
  is 
  called 
  a 
  peneplain 
  ; 
  a 
  peneplain 
  

   of 
  this 
  date 
  was 
  produced 
  quite 
  generally 
  throughout 
  the 
  Appala- 
  

   chian 
  region 
  and 
  eastern 
  Canada, 
  and 
  it 
  is 
  reasonable 
  to 
  assume 
  

   that 
  it 
  was 
  also 
  produced 
  here. 
  

  

  CENOZOIC 
  HISTORY 
  

  

  At 
  the 
  close 
  of 
  the 
  Mesozoic 
  the 
  region 
  was 
  again 
  uplifted. 
  The 
  

   low 
  altitude 
  peneplain 
  which 
  had 
  been 
  produced 
  over 
  the 
  Adiron- 
  

   dack 
  region 
  was 
  elevated 
  some 
  1500 
  feet 
  or 
  more, 
  and 
  rapid 
  

   erosion 
  of 
  its 
  surface 
  began. 
  Stream 
  valleys 
  were 
  cut 
  down 
  and 
  

   broadened. 
  It 
  is 
  the 
  depth 
  of 
  the 
  valley 
  cutting 
  below 
  the 
  old 
  

   peneplain 
  level 
  which 
  enables 
  us 
  to 
  estimate 
  the 
  amount 
  of 
  the 
  

   uplift. 
  The 
  divides 
  between 
  the 
  valleys, 
  however, 
  have 
  been 
  but 
  

   little 
  worn 
  down 
  during 
  the 
  time 
  that 
  has 
  passed 
  since 
  the 
  uplift. 
  

   These 
  divides 
  rise 
  now 
  to 
  uniform 
  levels, 
  the 
  levels 
  of 
  the 
  old 
  

   peneplain. 
  An 
  observer, 
  standing 
  upon 
  one 
  of 
  these 
  divide 
  sum- 
  

   mits 
  and 
  looking 
  abroad 
  to 
  the 
  others, 
  receives 
  the 
  impression 
  of 
  

   standing 
  upon 
  the 
  surface 
  of 
  a 
  plain 
  and 
  has 
  merely 
  to 
  imagine 
  

   the 
  valleys 
  refilled 
  with 
  material 
  in 
  order 
  to 
  picture 
  the 
  plain 
  as 
  

   it 
  was 
  at 
  the 
  time 
  of 
  the 
  uplift. 
  

  

  This 
  old 
  peneplained 
  surface 
  is 
  readily 
  made 
  out 
  over 
  most 
  of 
  

   the 
  Adirondack 
  region. 
  But 
  in 
  the 
  extreme 
  east 
  it 
  seems 
  to 
  fail 
  

   and 
  the 
  divide 
  summits 
  rise 
  to 
  very 
  discordant 
  levels 
  instead 
  of 
  

   being 
  uniform. 
  This 
  we 
  take 
  to 
  mean 
  that 
  here 
  renewed 
  slipping 
  

   along 
  the 
  old 
  faults 
  occurred 
  as 
  a 
  phase 
  of 
  the 
  uplift; 
  that 
  the 
  

   Champlain 
  trough 
  displayed 
  anew 
  its 
  tendency 
  to 
  sag 
  relative 
  to 
  

  

  