﻿140 
  Williams 
  — 
  Devonian 
  Interval 
  in 
  northern 
  Arkansas. 
  

  

  B2 
  = 
  A2, 
  but 
  B2 
  is 
  a 
  hard, 
  greenish 
  black 
  rock 
  with 
  rounded 
  

   black 
  pebbles 
  ; 
  B3 
  = 
  A3. 
  The 
  3d 
  section 
  is 
  taken 
  at 
  a 
  point 
  

   about 
  half 
  a 
  mile 
  up 
  the 
  creek, 
  on 
  the 
  east 
  side. 
  Cl, 
  2 
  and 
  3 
  

   correspond 
  to 
  A2 
  ; 
  and 
  consist 
  first 
  of 
  black 
  shales, 
  with 
  a 
  

   band 
  of 
  hard 
  black 
  limestone 
  4 
  inches 
  thick 
  (C2) 
  in 
  the 
  midst. 
  

   This 
  is 
  followed 
  above 
  by 
  the 
  St. 
  Joe 
  marble 
  (C4), 
  and 
  is 
  capped 
  

   by 
  Boone 
  chert 
  (C5). 
  

  

  At 
  the 
  Buck 
  Horn 
  locality 
  the 
  interval, 
  between 
  the 
  pink 
  

   Silurian 
  limestone 
  which 
  contains 
  no 
  fossils 
  and 
  the 
  overlying 
  

   red 
  Carboniferous 
  marble, 
  contains 
  a 
  few 
  feet 
  of 
  typical 
  black 
  

   shale, 
  such 
  as 
  represents 
  the 
  Devonian 
  interval 
  in 
  Tennessee. 
  

   It 
  contains 
  a 
  small 
  Lingula 
  which 
  may 
  be 
  called 
  L. 
  sjpatulata^ 
  

   until 
  some 
  one 
  succeeds 
  in 
  determining 
  where 
  to 
  draw 
  the 
  

   specific 
  limit 
  between 
  the 
  minute 
  forms 
  of 
  the 
  Genesee 
  shale 
  

   of 
  ]^ew 
  York 
  and 
  the 
  several 
  forms 
  wdiich 
  succeed 
  it 
  in 
  the 
  

   black 
  shale 
  strata 
  of 
  the 
  Waverly 
  of 
  Ohio. 
  

  

  Associated 
  with 
  the 
  Lingula 
  are 
  Conodonts, 
  as 
  in 
  the 
  Gene- 
  

   see 
  and 
  similar 
  shales 
  in 
  New 
  York 
  state. 
  Two 
  hundred 
  

   yards 
  east 
  of 
  this 
  section 
  (at 
  1246 
  B), 
  the 
  same 
  interval 
  is 
  occu- 
  

   pied 
  by 
  a 
  hard, 
  siliceous, 
  greenish-black 
  rock 
  with 
  very 
  hard, 
  

   rounded 
  black 
  nodules, 
  with 
  no 
  fossils 
  seen. 
  In 
  both 
  of 
  these 
  

   interval-filling 
  rocks 
  are 
  found 
  the 
  coarse, 
  polished, 
  siliceous 
  

   grains 
  so 
  characteristic 
  of 
  the 
  Sylamore 
  sandstone, 
  indicating 
  

   identity 
  of 
  origin 
  for 
  the 
  three 
  kinds 
  of 
  material. 
  The 
  black 
  

   shale 
  may 
  be 
  called 
  the 
  Eureka 
  shale, 
  stratigraphically 
  speak- 
  

   ing 
  ; 
  but 
  its 
  identity 
  paleontologically 
  has 
  not 
  heretofore 
  been 
  

   established. 
  

  

  The 
  next 
  place 
  from 
  which 
  evidence 
  has 
  been 
  seen 
  is 
  Roast- 
  

   ing 
  Ear 
  Creek, 
  8 
  miles 
  southeast 
  of 
  Big 
  Flat, 
  in 
  the 
  w^estern 
  

   part 
  of 
  Stone 
  County. 
  

  

  No. 
  1281. 
  Roasting 
  Ear 
  Creek, 
  Stone 
  Co. 
  

  

  The 
  materials 
  examined 
  from 
  this 
  section 
  were 
  collected 
  by 
  

   Weller, 
  from 
  a 
  point 
  8 
  miles 
  southeast 
  of 
  Big 
  Flat, 
  July 
  10, 
  

   1892. 
  The 
  fossils 
  in 
  the 
  red 
  limestone 
  (Al) 
  were 
  supposed 
  by 
  

   him 
  to 
  have 
  fallen 
  down. 
  They 
  are 
  all 
  Trenton 
  fossils, 
  show- 
  

   ing 
  the 
  rock 
  to 
  be 
  the 
  Polk 
  Bayou 
  limestone. 
  The 
  shale 
  (A2) 
  

   contains 
  the 
  same 
  kind 
  of 
  black 
  pebbles 
  seen 
  in 
  1246 
  B2. 
  

  

  Here 
  the 
  interval-tilling 
  material 
  is 
  a 
  green 
  siliceous 
  shale, 
  

   more 
  or 
  less 
  calcareous, 
  containing 
  fragments 
  of 
  shells 
  and 
  of 
  

   what 
  appears 
  to 
  be 
  broken 
  tisli 
  teeth, 
  and 
  well-rounded 
  pebbles 
  

   or 
  nodules 
  of 
  hardened 
  bhick 
  shale 
  ; 
  everything 
  too 
  much 
  

   broken 
  and 
  polished 
  to 
  indicate 
  the 
  genus 
  or 
  even 
  class 
  of 
  

   organisms 
  w4th 
  certainty. 
  This 
  rests 
  immediately 
  upon 
  red 
  

   marble 
  of 
  Trenton 
  age, 
  the 
  Polk 
  Bayou 
  limestone. 
  The 
  over- 
  

   lying 
  rock 
  is 
  not 
  reported. 
  

  

  About 
  twenty-five 
  miles 
  northwest 
  of 
  this 
  section 
  is 
  seen 
  

   another 
  outcrop 
  at 
  the 
  " 
  narrows," 
  3 
  miles 
  from 
  the 
  mouth 
  of 
  

   Rush 
  Creek, 
  in 
  Marion 
  County. 
  

  

  