﻿4:26 
  J. 
  Barrell 
  — 
  The 
  Piedmont 
  Terraces 
  

  

  interfluvial 
  ridge, 
  except 
  under 
  the 
  most 
  favorable 
  con- 
  

   ditions. 
  This 
  difficulty 
  has 
  been 
  due 
  in 
  some 
  measure, 
  

   it 
  is 
  felt, 
  to 
  a 
  lack 
  of 
  suitable 
  criteria 
  by 
  means 
  of 
  which 
  

   one 
  may 
  distinguish 
  between 
  the 
  results 
  of 
  fluvial 
  and 
  

   marine 
  denudation. 
  An 
  important 
  phase 
  of 
  Professor 
  

   Barrell's 
  study 
  was 
  the 
  development 
  of 
  such 
  criteria 
  and 
  

   his 
  work 
  has 
  opened 
  up 
  a 
  number 
  of 
  very 
  interesting 
  

   lines 
  of 
  investigation. 
  It 
  may 
  be 
  surmised, 
  also, 
  that 
  

   the 
  hypothesis 
  of 
  many 
  erosion 
  planes 
  of 
  marine 
  origin 
  

   may 
  stimulate 
  others, 
  as 
  it 
  did 
  Professor 
  Barrell, 
  to 
  de- 
  

   tect 
  and 
  correlate 
  in 
  a 
  comprehensive 
  way 
  some 
  of 
  the 
  

   finer 
  topographic 
  features 
  the 
  importance 
  of 
  which 
  has 
  

   been 
  made 
  evident. 
  

  

  Editorial 
  note 
  on 
  the 
  Piedmont 
  Terraces 
  of 
  Maryland. 
  

  

  Professor 
  Barrell 
  was 
  led 
  to 
  study 
  the 
  Piedmont 
  ter- 
  

   races 
  in 
  Maryland, 
  in 
  1912, 
  because 
  of 
  certain 
  questions 
  

   that 
  had 
  arisen 
  in 
  connection 
  with 
  his 
  New 
  England 
  

   field 
  work 
  of 
  the 
  previous 
  year. 
  He 
  had 
  observed 
  at 
  

   several 
  localities 
  elongated 
  flat-topped 
  hills 
  or 
  ridges 
  

   which 
  he 
  thought 
  might 
  be 
  remnants 
  of 
  a 
  marine 
  plain. 
  

   Because 
  of 
  the 
  possibility 
  that 
  critical 
  features 
  might 
  

   have 
  been 
  obliterated 
  by 
  glaciation 
  he 
  noted 
  at 
  the 
  time 
  

   that 
  it 
  would 
  be 
  necessary 
  to 
  "look 
  for 
  similar 
  features 
  

   in 
  an 
  ungiaciated 
  region 
  and 
  if 
  sea 
  cliffs 
  are 
  found, 
  look 
  

   for 
  retreatal 
  gravels." 
  Before 
  going 
  into 
  the 
  field 
  in 
  

   1912 
  he 
  had 
  reached 
  the 
  conclusion, 
  however, 
  that 
  the 
  

   Connecticut 
  terraces 
  were 
  of 
  marine 
  origin 
  and 
  had 
  ten- 
  

   tatively 
  assigned 
  a 
  similar 
  origin 
  to 
  the 
  Piedmont 
  ter- 
  

   races 
  of 
  Maryland 
  on 
  the 
  basis 
  of 
  the 
  similarity 
  of 
  the 
  

   projected 
  profiles 
  of 
  the 
  two 
  regions. 
  As 
  a 
  result 
  of 
  this 
  

   conclusion 
  Professor 
  BarrelPs 
  main 
  interest, 
  when 
  he 
  

   visited 
  the 
  Maryland 
  localities, 
  centered 
  about 
  the 
  pos- 
  

   sible 
  presence 
  of 
  marine 
  gravels. 
  

  

  It 
  may 
  be 
  said 
  in 
  brief 
  that 
  gravels 
  were 
  observed 
  on 
  

   the 
  520-540 
  and 
  730-J45 
  foot 
  terraces 
  (Plate 
  VI) 
  of 
  a 
  

   character 
  and 
  in 
  positions 
  which 
  indicated 
  to 
  Professor 
  

   Barrell 
  their 
  marine 
  origin. 
  Reference 
  to 
  this 
  point 
  is 
  

   found 
  in 
  the 
  discussion 
  of 
  the 
  original 
  address 
  (p. 
  695). 
  

   On 
  the 
  higher 
  terraces, 
  however, 
  nothing 
  suggesting 
  

   water-worn 
  gravels 
  was 
  seen. 
  

  

  The 
  "Lafayette" 
  formation 
  was 
  studied 
  in 
  the 
  region 
  

   west 
  and 
  northwest 
  of 
  Catonsville. 
  At 
  the 
  highest 
  point 
  

  

  