﻿of 
  the 
  Northern 
  Appalachians. 
  347 
  

  

  an 
  elevation 
  of 
  about 
  1,650 
  feet, 
  was 
  dissected 
  to 
  an 
  ad- 
  

   vanced 
  degree 
  with 
  respect 
  to 
  a 
  baselevel 
  at 
  a 
  present 
  

   elevation 
  of 
  about 
  1,400 
  feet. 
  This 
  corresponds 
  to 
  

   the 
  relation 
  just 
  described 
  in 
  the 
  Milford 
  — 
  Port 
  Jervis 
  

   locality. 
  

  

  The 
  crest 
  of 
  the 
  Kittatinny 
  ridge 
  throughout 
  the 
  

   greater 
  part 
  of 
  its 
  length 
  is 
  part 
  of 
  the 
  peneplain 
  which 
  

   forms 
  the 
  surface 
  of 
  the 
  Monticello 
  plateau. 
  The 
  latter, 
  

   indeed, 
  displays 
  a 
  much 
  better 
  development 
  of 
  the 
  Kitta- 
  

   tinny 
  peneplain 
  than 
  does 
  the 
  ridge 
  from 
  which 
  it 
  was 
  

   named. 
  The 
  clear 
  evidence 
  both 
  north 
  and 
  south 
  of 
  the 
  

   Delaware 
  that 
  the 
  Kittatinny 
  peneplain 
  was 
  dissected 
  

   through 
  a 
  long 
  cycle 
  of 
  erosion 
  with 
  respect 
  to 
  a 
  base- 
  

   level 
  at 
  about 
  1,400 
  feet 
  is 
  to 
  be 
  correlated 
  with 
  that 
  

   derived 
  from 
  the 
  considerable 
  number 
  of 
  apparent 
  wind 
  

  

  Fig. 
  13. 
  

  

  VlfTTTf/ 
  

  

  Fig. 
  13. 
  — 
  Composite 
  valley 
  slopes 
  resulting 
  from 
  a 
  series 
  of 
  quickening 
  

   uplifts. 
  

  

  gaps 
  which 
  cross 
  Kittatinny 
  Ridge 
  at 
  about 
  this 
  same 
  

   elevation. 
  The 
  evidence 
  from 
  the 
  plateau 
  supports 
  the 
  

   idea 
  that 
  these 
  low 
  passes 
  are 
  true 
  wind 
  gaps 
  and 
  that 
  

   they 
  indicate 
  a 
  higher 
  degree 
  of 
  superposed 
  drainage 
  

   during 
  the 
  1,400 
  foot 
  cycle 
  than 
  during 
  the 
  following 
  

   cycles. 
  A 
  large 
  part 
  of 
  the 
  adjustment 
  to 
  structure 
  took 
  

   place 
  during 
  the 
  closing 
  stages 
  of 
  the 
  1,400 
  foot 
  erosion 
  

   cycle. 
  

  

  The 
  evidence 
  of 
  successive 
  baselevels 
  presented 
  in 
  the 
  

   last 
  three 
  sections 
  is 
  convincing 
  in 
  regard 
  to 
  their 
  relative 
  

   duration. 
  They 
  represent 
  successive 
  uplifts 
  in 
  a 
  quick- 
  

   ening 
  series 
  and 
  the 
  general 
  character 
  of 
  the 
  valley 
  slopes 
  

   is 
  shown 
  in 
  fig. 
  13. 
  These 
  latter, 
  it 
  should 
  be 
  said, 
  per- 
  

   tain 
  to 
  the 
  Pleistocene-Pliocene 
  series; 
  for 
  the 
  upper 
  

   and 
  outer 
  parts 
  of 
  a 
  river 
  system 
  showing 
  older 
  stages 
  

   the 
  slopes 
  are 
  in 
  general 
  proportionately 
  flatter. 
  22 
  In 
  

  

  22 
  J. 
  Barrell. 
  Rhythms 
  and 
  the 
  Measurements 
  of 
  Geologic 
  Time. 
  Bull. 
  

   ■Geol. 
  Soc. 
  Am., 
  vol. 
  28, 
  p. 
  762, 
  1917. 
  

  

  