﻿Appalachian 
  Geosyncline. 
  

  

  457 
  

  

  oblique, 
  the 
  Chemung 
  sedi- 
  

   ments 
  appearing 
  lower 
  down 
  

   toward 
  the 
  east. 
  It 
  is 
  to 
  be 
  

   noted 
  that 
  the 
  Jennings 
  for- 
  

   mation 
  as 
  seen 
  a 
  hundred 
  and 
  

   thirty 
  miles 
  southwest 
  in 
  the 
  

   Pawpaw 
  - 
  Hancock 
  quadran- 
  

   gles 
  is 
  also 
  stated 
  in 
  the 
  folio 
  

   of 
  that 
  region 
  to 
  contain 
  Che- 
  

   mung 
  and 
  Portage 
  faunas. 
  

  

  In 
  eastern 
  New 
  York 
  the 
  

   Oneonta 
  gray 
  sandstone 
  and 
  

   red 
  shale 
  marks 
  there 
  the 
  be- 
  

   ginning 
  of 
  Catskill 
  conditions 
  

   early 
  in 
  Portage 
  time. 
  This 
  

   section, 
  one 
  hundred 
  and 
  fifty 
  

   miles 
  to 
  the 
  southwest 
  of 
  the 
  

   New 
  York 
  exposures, 
  shows 
  

   that 
  the 
  Oneonta 
  is 
  missing 
  

   even 
  on 
  the 
  eastern 
  outcrop. 
  

   Catskill 
  conditions 
  did 
  not 
  

   begin 
  here 
  until 
  in 
  Chemung 
  

   time. 
  The 
  progressive 
  change 
  

   toward 
  the 
  southwest 
  is 
  seen 
  

   further 
  in 
  that 
  the 
  Jennings 
  

   formation, 
  the 
  marine 
  upper 
  

   Devonian 
  of 
  Virginia 
  and 
  

   Maryland, 
  is 
  at 
  least 
  twice 
  

   as 
  thick 
  in 
  Maryland 
  as 
  in 
  

   Schuylkill 
  County 
  of 
  Penn- 
  

   sylvania. 
  Catskill 
  sedimen- 
  

   tation 
  did 
  not 
  begin 
  in 
  Mary- 
  

   land 
  until 
  still 
  later. 
  

  

  The 
  transition 
  beds 
  at 
  the 
  

   base 
  of 
  the 
  Catskill 
  are 
  marked 
  

   by 
  the 
  occurrence 
  of 
  gray 
  or 
  

   olive 
  shales 
  of 
  Chemung 
  type 
  

   interbedded 
  with 
  Catskill 
  red 
  

   shales. 
  These 
  are 
  well 
  ex- 
  

   posed 
  on 
  the 
  flank 
  of 
  a 
  minor 
  

   syncline 
  at 
  Landingdale 
  on 
  

   the 
  Schuylkill 
  River 
  a 
  few 
  

   miles 
  southeast 
  of 
  the 
  detailed 
  

   section. 
  The 
  significant 
  fea- 
  

   ture 
  to 
  be 
  observed 
  here 
  is 
  

   that 
  olive 
  shales 
  occur 
  both 
  

   above 
  and 
  below 
  a 
  horizon 
  

   of 
  red 
  shale 
  and 
  sandstone. 
  

   Marine 
  fossils 
  occur 
  in 
  that 
  

  

  COLUMNAR 
  SECTION 
  

  

  LITTLE 
  SCHUYLKILL 
  

  

  SCHUYLKILL 
  RIVER 
  

  

  -, 
  ^~ 
  

  

  l*-is 
  miles— 
  i 
  

   X=Mudcracxs 
  <i> 
  

  

  F,E,CRA= 
  o 
  

  

  Warine 
  fossils 
  o 
  ^ 
  

   Red 
  rocks 
  shown 
  o 
  § 
  

   in 
  heavy 
  partem 
  o 
  •" 
  

  

  " 
  950 
  

  

  Not 
  exp. 
  

  

  Nor 
  exp. 
  

  

  

  $ 
  I 
  

  

  5855 
  

  

  c 
  ■- 
  

  

  0t>W3to°O 
  ,s 
  O°ci 
  

  

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  exp. 
  

  

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  exp. 
  

  

  Nor 
  exp. 
  

  

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  exp. 
  

  

  c 
  o 
  

  

  O 
  1= 
  

  

  — 
  950 
  

  

  ■s-g 
  

  

  >S. 
  

  

  £-1 
  

  

  ■gffi 
  

  

  O 
  3, 
  

  

  + 
  -o 
  

   S.2J 
  

  

  SI 
  

  

  1° 
  

  

  1725+ 
  

  

  — 
  10*12 
  

  

  Section 
  eroded 
  

  

  Fig. 
  2. 
  Columnar 
  sections 
  of 
  Pocono, 
  

   Catskill, 
  and 
  Portage 
  - 
  Chemung 
  rocks 
  

   on 
  the 
  Schuylkill 
  and 
  Little 
  Schuylkill 
  

   Eivers. 
  

  

  