﻿228 
  J. 
  Barrell 
  — 
  The 
  Piedmont 
  Terraces 
  

  

  Editorial 
  Preface. 
  

  

  The 
  physiographic 
  problems 
  of 
  the 
  Appalachian 
  Prov- 
  

   ince, 
  especially 
  of 
  its 
  seaward 
  side, 
  had 
  interested 
  Pro- 
  

   fessor 
  Barrell 
  for 
  many 
  years, 
  in 
  fact 
  from 
  the 
  beginning 
  

   of 
  his 
  career 
  as 
  a 
  geologist. 
  His 
  interest 
  in 
  them, 
  how- 
  

   ever, 
  did 
  not 
  become 
  acnte 
  nntil 
  he 
  discovered 
  the 
  evi- 
  

   dence, 
  in 
  1911, 
  which 
  led 
  him 
  to 
  recognize 
  the 
  existence 
  

   of 
  many 
  planes 
  of 
  erosion 
  in 
  western 
  Connecticut 
  and 
  to 
  

   conclude 
  from 
  their 
  stair-like 
  character, 
  their 
  linear 
  plan, 
  

   and 
  because 
  they 
  had 
  always 
  faced 
  the 
  sea, 
  that 
  they 
  were 
  

   probably 
  of 
  marine 
  origin. 
  

  

  During 
  the 
  following 
  year 
  (1912) 
  he 
  devoted 
  much 
  

   time 
  to 
  the 
  study 
  of 
  the 
  Connecticut 
  terraces 
  from 
  the 
  

   point 
  of 
  view 
  of 
  their 
  marine 
  origin 
  and 
  he 
  further 
  ex- 
  

   tended 
  his 
  field 
  of 
  study 
  so 
  as 
  to 
  include 
  the 
  entire 
  sea- 
  

   ward 
  slope 
  of 
  the 
  Appalachian 
  region 
  as 
  far 
  south 
  as 
  

   Maryland. 
  The 
  results 
  of 
  this 
  study 
  were 
  presented 
  in 
  

   two 
  papers 
  — 
  "Piedmont 
  Terraces 
  of 
  the 
  Northern 
  Appa- 
  

   lachians 
  and 
  Their 
  Mode 
  of 
  Origin" 
  and 
  "Post- 
  Jurassic 
  

   History 
  of 
  the 
  Northern 
  Appalachians" 
  1 
  — 
  at 
  the 
  Decem- 
  

   ber 
  meeting 
  of 
  the 
  Geological 
  Society 
  of 
  America 
  in 
  New 
  

   Haven 
  in 
  1912. 
  

  

  The 
  work 
  on 
  which 
  these 
  two 
  papers 
  were 
  based, 
  and 
  

   which 
  Professor 
  Barrell 
  was 
  carrying 
  on, 
  may 
  be 
  sum- 
  

   marized 
  under 
  the 
  following 
  headings 
  : 
  

  

  1. 
  Study 
  of 
  the 
  topographic 
  maps 
  on 
  a 
  scale 
  of 
  1 
  : 
  62,- 
  

   500 
  covering 
  New 
  England, 
  eastern 
  New 
  York, 
  New 
  Jer- 
  

   sey, 
  eastern 
  Pennsylvania, 
  and 
  Maryland. 
  The 
  purpose 
  

   was 
  to 
  gain 
  a 
  general 
  idea 
  of 
  the 
  extent 
  of 
  the 
  terraces 
  

   and 
  their 
  modes 
  of 
  expression 
  in 
  different 
  regions. 
  Cer- 
  

   tain 
  critical 
  features 
  were 
  looked 
  for, 
  such 
  as 
  wind 
  gaps, 
  

   spurs, 
  and 
  composite 
  slopes. 
  The 
  limitations 
  imposed 
  

   by 
  the 
  imperfect 
  representation 
  of 
  much 
  of 
  the 
  topog- 
  

   raphy 
  and 
  the 
  necessity 
  of 
  checking 
  up 
  details 
  in 
  the 
  field 
  

   were 
  clearly 
  kept 
  in 
  mind. 
  

  

  2. 
  The 
  preparation 
  of 
  a 
  map 
  of 
  the 
  region 
  mentioned 
  

   above 
  on 
  a 
  scale 
  of 
  10 
  miles 
  to 
  the 
  inch 
  showing 
  the 
  geo- 
  

   graphic 
  extent 
  of 
  the 
  marine 
  terraces. 
  Also 
  a 
  map 
  cov- 
  

   ering 
  the 
  same 
  region 
  and 
  on 
  the 
  same 
  scale 
  showing 
  

   wind 
  gaps 
  and 
  accordant 
  valley 
  terraces. 
  

  

  1 
  Abstracts 
  in 
  Bull. 
  Geol. 
  Soc. 
  Amer., 
  vol. 
  24, 
  pp. 
  688-696, 
  1913. 
  

  

  I 
  am 
  under 
  great 
  obligation 
  to 
  Dr. 
  Isaiah 
  Bowman 
  for 
  advice 
  and 
  for 
  

   information 
  bearing 
  on 
  the 
  early 
  stages 
  of 
  Professor 
  BarrelPs 
  work. 
  My 
  

   own 
  knowledge, 
  gained 
  through 
  random 
  talks 
  with 
  Professor 
  Barrell 
  and 
  

   as 
  a 
  result 
  much 
  too 
  incomplete 
  to 
  do 
  justice 
  to 
  his 
  ideas, 
  covered 
  only 
  the 
  

   late 
  stages. 
  

  

  