﻿of 
  the 
  Northern 
  Appalachians. 
  24.9 
  

  

  The 
  whole 
  of 
  Connecticut 
  (southern 
  New 
  England) 
  has 
  

   experienced 
  broad 
  uplifts 
  of 
  the 
  crust 
  recent 
  enough 
  so 
  

   that 
  the 
  belts 
  of 
  resistant 
  formations 
  have 
  not 
  been 
  re- 
  

   moved 
  to 
  any 
  great 
  extent 
  by 
  erosion, 
  yet 
  long 
  enough 
  

   ago 
  to 
  permit 
  narrow 
  valleys 
  to 
  be 
  cut 
  deep 
  into 
  the 
  

   harder 
  rocks 
  while 
  the 
  softer 
  rocks, 
  in 
  the 
  central 
  low- 
  

   land, 
  have 
  been 
  worn 
  down 
  to 
  a 
  peneplane 
  of 
  a 
  lower 
  

   level. 
  It 
  is 
  clear, 
  then, 
  that 
  the 
  resistance 
  of 
  the 
  various 
  

   kinds 
  of 
  rocks 
  to 
  erosion 
  has 
  been 
  very 
  unlike. 
  It 
  is 
  an 
  

   understatement 
  rather 
  than 
  an 
  overstatement 
  to 
  say 
  that 
  

   the 
  interval 
  needed 
  to 
  reduce 
  the 
  resistant 
  formations 
  of 
  

   the 
  upland 
  to 
  a 
  peneplane 
  would 
  have 
  to 
  be 
  more 
  than 
  

   ten 
  times 
  greater 
  than 
  that 
  which 
  has 
  witnessed 
  the 
  

   development 
  of 
  a 
  peneplane 
  in 
  the 
  central 
  lowland. 
  

  

  The 
  physiographic 
  history 
  of 
  the 
  upland 
  is 
  complex, 
  

   but 
  involves 
  three 
  major 
  problems. 
  These 
  are 
  (1) 
  the 
  

   causes 
  which 
  have 
  determined 
  the 
  height 
  and 
  distribu- 
  

   tion 
  of 
  the 
  highest 
  hills 
  which 
  integrate 
  into 
  the 
  sky-line 
  

   as 
  seen 
  in 
  a 
  broad 
  view 
  from 
  the 
  highest 
  points, 
  (2) 
  the 
  

   history 
  of 
  the 
  broad 
  rolling 
  surfaces 
  and 
  higher 
  open 
  val- 
  

   leys 
  of 
  the 
  upland, 
  the 
  agricultural 
  portions 
  of 
  the 
  pla- 
  

   teaus, 
  and 
  (3) 
  the 
  history 
  of 
  the 
  deeper 
  and 
  narrower 
  

   river 
  valleys 
  showing 
  steep 
  rocky 
  slopes, 
  rock 
  benches, 
  

   and 
  drift 
  filled 
  floors. 
  

  

  For 
  the 
  treatment 
  of 
  the 
  first 
  and 
  second 
  of 
  these 
  prob- 
  

   lems 
  the 
  western 
  upland 
  of 
  Connecticut 
  appears 
  to 
  be 
  the 
  

   most 
  favorable 
  region 
  of 
  any 
  part 
  of 
  the 
  Piedmont 
  Pla- 
  

   teau, 
  of 
  which 
  it 
  is 
  a 
  separated 
  member. 
  There 
  are 
  sev- 
  

   eral 
  reasons 
  for 
  this. 
  It 
  is 
  in 
  closer 
  relation 
  to 
  the 
  sea 
  

   than 
  is 
  the 
  Piedmont 
  Plateau 
  southwest 
  of 
  the 
  Delaware 
  ; 
  

   the 
  area 
  is 
  underlain 
  by 
  broad 
  resistant 
  formations 
  which 
  

   have 
  preserved 
  to 
  a 
  greater 
  degree 
  the 
  initial 
  topo- 
  

   graphic 
  outlines. 
  Chiefly, 
  however, 
  the 
  region 
  is 
  valu- 
  

   able 
  for 
  study 
  because 
  the 
  structure 
  strikes 
  toward 
  the 
  

   sea 
  instead 
  of 
  parallel 
  with 
  it, 
  as 
  is 
  the 
  case 
  from 
  New 
  

   Jersey 
  to 
  Georgia. 
  The 
  result 
  is 
  that, 
  as 
  the 
  plateau 
  

   surface 
  is 
  traced 
  inland 
  along 
  the 
  interfluvial 
  ridges, 
  the 
  

   changes 
  are 
  those 
  due 
  mainly 
  to 
  differences 
  in 
  physio- 
  

   graphic 
  history 
  and 
  only 
  in 
  minor 
  degree 
  to 
  changes 
  in 
  

   rock 
  formation. 
  From 
  New 
  Jersey 
  south, 
  on 
  the 
  con- 
  

   trary, 
  in 
  following 
  the 
  sloping 
  Piedmont 
  Plateau 
  in- 
  

   land 
  along 
  the 
  interfluvial 
  belts, 
  the 
  rock 
  formations 
  

   repeatedly 
  change 
  and 
  are 
  the 
  major 
  factor 
  in 
  determin- 
  

   ing 
  the 
  surface 
  forms. 
  

  

  