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  AMERICAN 
  JOURNAL 
  OF 
  SCIENCE 
  

  

  [FOURTH 
  SERIES.] 
  

  

  Art. 
  XVII.— 
  The 
  Piedmont 
  Terraces 
  of 
  the 
  Northern 
  

   Appalachians; 
  by 
  Joseph 
  Barbell. 
  

  

  Edited 
  by 
  H. 
  H. 
  Eobinson. 
  

  

  Contents.* 
  

  

  Editorial 
  Preface. 
  

  

  Introduction 
  : 
  Difficulties 
  of 
  the 
  fluvial 
  peneplane 
  hypothesis. 
  

   Citation 
  from 
  Master 
  of 
  Science 
  thesis, 
  with 
  editorial 
  note. 
  

   Methods 
  of 
  map 
  study: 
  

  

  Introduction. 
  

  

  Emphasizing 
  of 
  contours. 
  

  

  Method 
  of 
  projected 
  profiles. 
  

   Complexity 
  of 
  the 
  physiographic 
  record: 
  

  

  Physiographic 
  divisions 
  of 
  Connecticut. 
  

  

  Complexity 
  of 
  the 
  Connecticut 
  record. 
  

  

  Editorial 
  note 
  on 
  projected 
  profiles 
  of 
  the 
  terraces 
  of 
  western 
  Con- 
  

   necticut. 
  

  

  Indications 
  from 
  the 
  Coastal 
  Plain 
  of 
  many 
  baselevels. 
  

  

  General 
  indications 
  of 
  wide 
  oscillations 
  of 
  the 
  strand-line. 
  

   Fluvial 
  peneplanes: 
  

  

  Editorial 
  note. 
  

  

  Ee-examination 
  of 
  the 
  Harrisburg 
  peneplain. 
  

  

  Evidence 
  of 
  baselevels 
  given 
  by 
  wind 
  gaps. 
  

  

  Significance 
  of 
  present 
  valley 
  forms. 
  

   Marine 
  peneplanes: 
  

  

  Competence 
  of 
  marine 
  denudation. 
  

  

  The 
  process 
  of 
  marine 
  denudation. 
  

  

  Typical 
  cases 
  of 
  marine 
  denudation. 
  

   Criteria 
  for 
  the 
  recognition 
  of 
  fluvial 
  and 
  marine 
  baselevels: 
  

  

  Outcrops 
  of 
  unconformities. 
  

  

  The 
  fall-line 
  and 
  relation 
  of 
  marine 
  planation 
  to 
  geologic 
  formations. 
  

   Enduring 
  distinctions 
  between 
  fluvial 
  and 
  marine 
  erosion. 
  

   Editorial 
  note 
  on 
  the 
  projected 
  profile 
  of 
  the 
  terraces 
  of 
  western 
  Massa- 
  

   chusetts 
  and 
  Connecticut. 
  

   Editorial 
  note 
  on 
  the 
  physiographic 
  history 
  of 
  the 
  region. 
  

   Editorial 
  note 
  on 
  the 
  Piedmont 
  Terraces 
  of 
  Maryland. 
  

  

  * 
  This 
  article 
  is 
  published 
  in 
  three 
  sections 
  but 
  the 
  entire 
  Contents 
  are 
  

   given 
  here. 
  The 
  second 
  part, 
  beginning 
  with 
  the 
  discussion 
  of 
  "Indica- 
  

   tions 
  from 
  the 
  Coastal 
  Plain 
  of 
  many 
  baselevels/ 
  ' 
  will 
  appear 
  in 
  the 
  May 
  

   number, 
  and 
  the 
  concluding 
  part, 
  beginning 
  with 
  "Criteria 
  for 
  the 
  rec- 
  

   ognition 
  of 
  fluvial 
  and 
  marine 
  baselevels, 
  ' 
  ' 
  will 
  appear 
  in 
  the 
  June 
  number. 
  

  

  Am. 
  Jour. 
  Sci.— 
  Fourth 
  Series, 
  Vol. 
  XLIX, 
  No. 
  292.— 
  April, 
  1920. 
  

  

  17 
  

  

  