﻿of 
  the 
  Northern 
  Appalachians. 
  235 
  

  

  lem 
  which 
  ended 
  in 
  the 
  recognition 
  of 
  the 
  numerous 
  

   terraces 
  and 
  the 
  assignment 
  to 
  them 
  of 
  a 
  marine 
  origin. 
  

   Professor 
  Barrell 
  became 
  interested 
  in 
  the 
  physiography 
  

   of 
  New 
  England 
  in 
  1909-1910 
  while 
  engaged 
  in 
  field 
  work 
  

   in 
  southwestern 
  Massachusetts 
  (Housatonic 
  folio). 
  In 
  

   the 
  latter 
  year 
  he 
  made 
  a 
  preliminary 
  map 
  study 
  of 
  the 
  

   general 
  physiographic 
  problem 
  on 
  the 
  basis 
  of 
  several 
  

   selected 
  sections 
  in 
  an 
  east-west 
  direction 
  across 
  Ver- 
  

   mont 
  and 
  Massachusetts 
  and 
  in 
  a 
  north-south 
  direction 
  

   along 
  the 
  Green 
  Mountains 
  and 
  Taconic 
  Range. 
  And 
  it 
  

   is 
  to 
  be 
  noted 
  that 
  the 
  topography 
  was 
  interpreted 
  on 
  the 
  

   basis 
  of 
  a 
  subaerial 
  origin 
  and 
  three 
  cycles 
  of 
  erosion 
  — 
  

   Jurassic, 
  Cretaceous, 
  and 
  Tertiary 
  — 
  except 
  that 
  the 
  Cre- 
  

   taceous 
  peneplane 
  in 
  part 
  was 
  considered 
  of 
  marine 
  

   origin. 
  The 
  results 
  of 
  this 
  study 
  are 
  recorded 
  in 
  a 
  dic- 
  

   tated 
  but 
  unchecked 
  manuscript 
  of 
  24 
  typewritten 
  pages 
  

   dated 
  December, 
  1910. 
  This 
  map 
  study 
  was 
  followed 
  by 
  

   a 
  field 
  study 
  of 
  selected 
  areas 
  in 
  the 
  latter 
  part 
  of 
  the 
  

   summer 
  of 
  1911. 
  These 
  areas 
  covered 
  most 
  of 
  north- 
  

   western 
  Connecticut, 
  western 
  Massachusetts, 
  and 
  the 
  

   extreme 
  southwestern 
  part 
  of 
  Vermont. 
  The 
  interpre- 
  

   tation 
  of 
  the 
  topography 
  followed 
  the 
  same 
  lines 
  as 
  the 
  

   preliminary 
  study 
  and 
  Professor 
  Barrell 
  was 
  on 
  the 
  

   look-out 
  for 
  evidence 
  of 
  a 
  Cretaceous 
  shore-line 
  in 
  Con- 
  

   necticut. 
  His 
  notes 
  on 
  the 
  topographic 
  details 
  of 
  several 
  

   localities 
  contain 
  the 
  question 
  "Is 
  this 
  a 
  sea-cliff 
  ?", 
  and 
  

   it 
  may 
  be 
  noted 
  that 
  the 
  features 
  so 
  questioned 
  were 
  

   later 
  taken 
  to 
  mark 
  either 
  the 
  Goshen 
  or 
  Litchfield 
  shore- 
  

   line. 
  Remnants 
  of 
  three 
  erosion 
  planes 
  were 
  dis- 
  

   tinguished 
  which 
  were 
  called 
  Jurassic, 
  Cretaceous 
  

   (Schooley), 
  and 
  Tertiary 
  (Harrisburg) 
  and 
  in 
  addition 
  

   some 
  evidence 
  was 
  found 
  of 
  a 
  fourth 
  which 
  lay 
  between 
  

   the 
  Schooley 
  and 
  Harrisburg. 
  In 
  order 
  to 
  determine 
  

   what 
  the 
  attitude 
  of 
  these 
  surfaces 
  was 
  nearer 
  sea-level, 
  

   a 
  projected 
  profile 
  was 
  drawn 
  covering 
  the 
  southern 
  half 
  

   of 
  western 
  Connecticut. 
  The 
  picture 
  which 
  this 
  pre- 
  

   sented 
  must 
  have 
  been 
  quite 
  unexpected, 
  for 
  it 
  showed 
  

   that 
  the 
  hills 
  forming 
  the 
  sky-line, 
  instead 
  of 
  descending 
  

   as 
  though 
  they 
  were 
  part 
  of 
  a 
  single 
  dissected 
  surface, 
  

   resolved 
  themselves 
  into 
  a 
  number 
  of 
  apparently 
  hori- 
  

   zontal 
  benches 
  differing 
  in 
  elevation 
  from 
  100 
  to 
  200 
  feet. 
  

   Further 
  study 
  showed 
  the 
  presence 
  of 
  these 
  benches 
  at 
  

   other 
  localities 
  and 
  because 
  of 
  their 
  attitude 
  and 
  near- 
  

   ness 
  to 
  the 
  sea 
  and 
  certain 
  erosional 
  details, 
  Professor 
  

  

  