﻿£28 
  J. 
  Barrel! 
  — 
  Piedmont 
  Terraces. 
  

  

  for 
  the 
  terrace, 
  his 
  argument 
  being 
  the 
  same 
  as 
  in 
  the 
  

   case 
  of 
  the 
  lower 
  terraces. 
  

  

  The 
  region 
  about 
  Reist 
  erst 
  own 
  is 
  briefly 
  described 
  as 
  

   a 
  very 
  gently 
  rolling 
  and 
  but 
  little 
  dissected 
  upland 
  

   remnant. 
  Water-worn 
  material 
  was 
  found 
  at 
  three 
  local- 
  

   ities 
  : 
  (A) 
  in 
  cultivated 
  fields 
  just 
  south 
  of 
  the 
  road 
  to 
  

   St. 
  George, 
  at 
  an 
  elevation 
  of 
  720 
  feet, 
  (B) 
  in 
  a 
  cultivated 
  

   field, 
  three-tenths 
  of 
  a 
  mile 
  from 
  the 
  turnpike, 
  on 
  the 
  

   north 
  side 
  of 
  the 
  road 
  that 
  leaves 
  the 
  Reisterstown 
  turn- 
  

   pike 
  one-half 
  mile 
  south 
  of 
  town 
  and 
  runs 
  south-west, 
  

   (C) 
  in 
  a 
  field 
  north 
  of 
  road 
  that 
  crosses 
  the 
  above 
  road 
  

   beyond 
  locality 
  (B) 
  and 
  one-quarter 
  mile 
  south-east 
  of 
  

   the 
  crossroads. 
  Some 
  of 
  the 
  collected 
  material 
  is 
  shown 
  

   in 
  fig. 
  18 
  and 
  is 
  lettered 
  as 
  above. 
  In 
  regard 
  to 
  localities 
  

   A 
  and 
  B 
  it 
  is 
  noted 
  that 
  "fields 
  contain 
  many 
  jDebbles 
  

   and 
  a 
  few 
  larger 
  fragments 
  of 
  coarse 
  vein 
  quartz 
  weath- 
  

   ered 
  from 
  the 
  underlying 
  mica 
  schist." 
  

  

  The 
  common 
  residual 
  material 
  in 
  the 
  vicinity 
  of 
  Reis- 
  

   terstown 
  was 
  found 
  to 
  be 
  a 
  coarse 
  gray 
  quartz 
  rock 
  which 
  

   weathered 
  easily 
  and 
  was 
  rarest 
  as 
  good 
  water-worn 
  

   pebbles 
  (left-hand 
  specimen, 
  fig. 
  18, 
  B.). 
  "White 
  vein 
  

   quartz 
  was 
  rather 
  common 
  ; 
  it 
  formed 
  most 
  of 
  the 
  small 
  

   pebbles 
  and 
  Avas 
  not 
  much 
  water-worn. 
  No 
  quartzite 
  was 
  

   observed 
  in 
  place 
  but 
  the 
  most 
  perfectly 
  rounded 
  pebbles 
  

   were 
  of 
  this 
  rock 
  (left-hand 
  specimen, 
  fig. 
  18, 
  C). 
  

  

  To 
  sum 
  up, 
  then. 
  Professor 
  Barrell 
  considered 
  it 
  im- 
  

   probable 
  that 
  these 
  gravels 
  were 
  of 
  fluviatile 
  origin 
  for 
  

   reasons 
  briefly 
  stated 
  in 
  the 
  original 
  discussion 
  referred 
  

   to, 
  whereas 
  their 
  wide-spread 
  distribution 
  on 
  terraces, 
  

   such 
  as 
  are 
  shown 
  by 
  the 
  profile 
  (PL 
  VI), 
  led 
  to 
  the 
  more 
  

   logical 
  conclusion 
  that 
  they 
  were 
  of 
  marine 
  origin. 
  It 
  is 
  

   true 
  that 
  these 
  gravels 
  and 
  their 
  associated 
  sediments 
  

   have 
  yielded 
  no 
  marine 
  fossils, 
  nor 
  indeed 
  fossils 
  of 
  any 
  

   description, 
  and 
  in 
  the 
  absence 
  of 
  generally 
  accepted 
  

   criteria 
  for 
  distinguishing 
  between 
  fluviatile 
  and 
  marine 
  

   gravels 
  on 
  a 
  physical 
  basis, 
  there 
  may 
  be 
  expected 
  a 
  

   diversity 
  of 
  opinion 
  as 
  to 
  their 
  origin 
  depending 
  largely 
  

   on 
  one's 
  general 
  point 
  of 
  view. 
  This 
  being 
  the 
  case, 
  it 
  is 
  

   evident 
  that 
  a 
  large 
  field 
  is 
  open 
  to 
  discriminating 
  study. 
  

  

  