﻿Williams 
  — 
  Devonian 
  Interval 
  in 
  northern 
  Arlcansas, 
  141 
  

  

  No. 
  1278. 
  Rush 
  Creek, 
  Marion 
  Co. 
  

  

  The 
  section 
  1278 
  was 
  taken 
  along 
  the 
  creek, 
  opposite 
  the 
  

   mines, 
  by 
  Weller, 
  July 
  9, 
  1891. 
  The 
  limestone 
  (A2), 
  coarse- 
  

   grained, 
  pinkish, 
  containing 
  Trenton 
  fossils, 
  is 
  thus 
  shown 
  to 
  

   be 
  the 
  Polk 
  Bayoic 
  limestone. 
  The 
  limestone 
  below 
  (Al 
  and 
  

   Bl) 
  is 
  probably 
  the 
  same 
  as 
  the 
  heavy 
  bedded 
  blue 
  limestone, 
  

   and, 
  though 
  no 
  fossils 
  are 
  seen 
  in 
  it, 
  the 
  probability 
  is 
  that 
  it 
  

   is 
  the 
  Izard 
  limestone 
  of 
  the 
  Reports. 
  The 
  coarse 
  saccha- 
  

   roidal 
  sandstone 
  (A3 
  and 
  B2) 
  is 
  the 
  Sylamore 
  sandstone. 
  The 
  

   red 
  marble 
  {A4: 
  and 
  B3) 
  contains 
  a 
  few 
  fossils 
  of 
  Carbonifer- 
  

   ous 
  age, 
  and 
  is 
  therefore 
  the 
  St. 
  Joe 
  marhle 
  of 
  the 
  Reports. 
  

   Section 
  1278 
  B 
  is 
  taken 
  on 
  the 
  hill, 
  three 
  miles 
  from 
  the 
  mouth 
  

   of 
  Rush 
  Creek. 
  The 
  evidence 
  that 
  the 
  Sylamore 
  sandstone 
  

   represents 
  the 
  Black 
  shale 
  (Eureka 
  shale) 
  is 
  clear 
  upon 
  com- 
  

   paring 
  the 
  sections 
  1278 
  and 
  1216. 
  This 
  interval-material 
  is 
  

   pinched 
  out 
  to 
  almost 
  nothing 
  in 
  the 
  following 
  section. 
  

  

  Another 
  section 
  was 
  seen 
  at 
  Dodd 
  City. 
  

  

  No. 
  1282. 
  Dodd 
  City, 
  Marion 
  Co. 
  

  

  The 
  section 
  reported 
  was 
  taken 
  at 
  a 
  point 
  8 
  miles 
  north 
  of 
  

   Dodd 
  City, 
  Durst's 
  spring, 
  by 
  Weller, 
  July 
  23, 
  1891. 
  He 
  

   reported 
  that 
  the 
  red 
  marble 
  (A3, 
  St. 
  Joe 
  marhle) 
  i-ests 
  directly 
  

   upon 
  the 
  blue-gray 
  limestone 
  (A2), 
  which 
  contains 
  fossils 
  show- 
  

   ing 
  it 
  to 
  be 
  the 
  Polk 
  Bayoic 
  (Trenton) 
  limestone. 
  Below 
  it 
  is 
  

   a 
  bed 
  of 
  the 
  Ordovician, 
  Saccharoidal 
  sandstone. 
  No 
  rock 
  

   was 
  discovered 
  in 
  the 
  interval, 
  but 
  the 
  gap 
  was 
  seen 
  separating 
  

   the 
  two 
  limestones, 
  and 
  the 
  upper 
  one 
  is 
  identical 
  (so 
  far 
  as 
  

   the 
  characters 
  of 
  the 
  limestone, 
  without 
  actually 
  seeing 
  fossils, 
  

   can 
  be 
  depended 
  upon) 
  with 
  the 
  St. 
  Joe 
  marble 
  of 
  the 
  other 
  

   sections. 
  We 
  see 
  here 
  a 
  case 
  of 
  a 
  true 
  interval, 
  representing 
  

   all 
  the 
  time 
  from 
  the 
  Trenton 
  to 
  the 
  Carboniferous, 
  certainly 
  

   later 
  than 
  the 
  Chouteau, 
  and 
  without 
  sufficient 
  disturbance 
  of 
  

   the 
  horizontality 
  of 
  the 
  rocks 
  to 
  make 
  the 
  unconformity 
  

   apparent. 
  

  

  A 
  few 
  miles 
  west 
  of 
  the 
  Roasting 
  Ear 
  Creek 
  section, 
  on 
  

   Long 
  Creek, 
  near 
  a 
  place 
  called 
  Providence, 
  Searcy 
  County 
  

   (Ittll 
  A), 
  is 
  seen 
  another 
  section, 
  with 
  the 
  Silurian 
  terrane 
  termi- 
  

   nated 
  by 
  St. 
  Clair 
  limestone.^ 
  and 
  then 
  about 
  two 
  feet 
  of 
  inter- 
  

   val, 
  filled 
  with 
  characteristic 
  Sylamore 
  sandstone 
  with 
  its 
  

   polished 
  siliceous 
  grains, 
  and 
  black 
  rounded 
  nodules. 
  

   No. 
  1414. 
  Long 
  Creek, 
  Searcy 
  Co. 
  

  

  This 
  section, 
  taken 
  along 
  the 
  bank 
  of 
  the 
  creek, 
  was 
  visited 
  

   by 
  Dr. 
  Branner 
  and 
  myself 
  ; 
  and 
  when 
  it 
  was 
  first 
  seen, 
  it 
  was 
  

   quite 
  impossible 
  to 
  imagine 
  that 
  the 
  two 
  limestones 
  were 
  not 
  

   actually 
  continuous. 
  The 
  beds 
  lie 
  nearly 
  horizontal, 
  and 
  a 
  

   stretch 
  of 
  their 
  exposed 
  edges 
  is 
  in 
  sight 
  for 
  several 
  hundred 
  

   feet. 
  The 
  interval 
  (A2) 
  was 
  discovered 
  only 
  after 
  search. 
  

   The 
  fossils 
  in 
  the 
  limestone 
  (Al) 
  belong 
  to 
  the 
  Niagara 
  fauna 
  

  

  