﻿Williams 
  — 
  Devonian 
  Interval 
  in 
  northern 
  Arkansas: 
  139 
  

  

  Akt. 
  XY. 
  — 
  The 
  Devonian 
  Interval 
  m 
  northern 
  Arhansas 
  j 
  

   by 
  Henry 
  S. 
  Williams. 
  

  

  Ik 
  numerous 
  places 
  in 
  northern 
  Arkansas 
  the 
  evidences 
  of 
  

   an 
  unconformity 
  separating 
  the 
  Silurian 
  from 
  the 
  overlying 
  

   Carboniferous 
  are 
  very 
  clear. 
  In 
  some 
  cases 
  there 
  is 
  no 
  rock- 
  

   material 
  separating 
  these 
  two 
  grand 
  terranes. 
  In 
  other 
  cases 
  

   there 
  are 
  greenish 
  shales, 
  or- 
  coarse 
  sandstone, 
  v^ith 
  polished 
  

   grains 
  and 
  rounded 
  nodules 
  of 
  black 
  shale 
  ; 
  and 
  in 
  the 
  western 
  

   sections 
  the 
  interval 
  is 
  occupied, 
  in 
  part, 
  by 
  a 
  black 
  shale, 
  the 
  

   Eureka 
  shale 
  of 
  the 
  Washington 
  County 
  report.^ 
  The 
  sand- 
  

   stone 
  when 
  present 
  is 
  called 
  the 
  Sylainore 
  sandstone 
  in 
  the 
  

   various 
  reports. 
  The 
  materials 
  discussed 
  in 
  this 
  paper 
  are 
  

   from 
  the 
  following 
  localities. 
  The 
  numbers 
  before 
  the 
  names 
  

   are 
  locality 
  numbers 
  of 
  the 
  United 
  States 
  Geological 
  Survey, 
  

   under 
  which 
  the 
  materials 
  studied 
  are 
  catalogued 
  preparatory 
  

   to 
  final 
  deposit 
  in 
  the 
  National 
  Museum. 
  

  

  1246. 
  Buck 
  Horn, 
  Stone 
  Co., 
  Arkansas. 
  I 
  1238. 
  St. 
  Joe, 
  Searcy 
  Co. 
  

  

  1281. 
  Roasting 
  Ear 
  Creek, 
  Stone 
  Co. 
  j 
  1277. 
  Cave 
  Creek. 
  Newton 
  Co 
  

   1278. 
  Rush 
  Creek, 
  Marion 
  Co. 
  

  

  1282. 
  Dodd 
  City, 
  Marion 
  Co. 
  

   1414. 
  Long 
  Creek, 
  Searcy 
  Co. 
  

  

  1410. 
  Eureka 
  Springs, 
  Carroll 
  Co. 
  

   1279. 
  War 
  Eagle 
  Creek, 
  "Washington 
  Co. 
  

   1291. 
  Buffalo 
  Fork, 
  Newton 
  Co. 
  

  

  On 
  passing 
  westward 
  from 
  Batesville, 
  the 
  first 
  locality, 
  from 
  

   which 
  specimens 
  representing 
  this 
  interval 
  have 
  come, 
  is 
  3 
  

   miles 
  north 
  of 
  Buck 
  Horn, 
  Stone 
  County 
  (No. 
  1246 
  A) 
  on 
  

   Cagen 
  Creek. 
  

  

  No. 
  1246. 
  Buck 
  Horn, 
  Stone 
  Co. 
  

  

  This 
  station 
  was 
  first 
  reported 
  by 
  Dr. 
  Branner 
  as 
  " 
  section 
  

   3, 
  14 
  N., 
  9 
  West, 
  at 
  John 
  Greenway's 
  ; 
  over 
  4 
  feet 
  black 
  shale 
  

   overlaid 
  by 
  one 
  foot 
  that 
  weathers 
  red." 
  It 
  is 
  82/11 
  of 
  Hop- 
  

   kins's 
  report 
  of 
  '89, 
  Oct. 
  3d 
  ; 
  and 
  was 
  reported 
  by 
  me 
  in 
  letters 
  

   Nov. 
  9, 
  '89, 
  as 
  " 
  a 
  black 
  shale 
  very 
  similar 
  to 
  the 
  Berea 
  of 
  Ohio." 
  

   Afterwards, 
  Mr. 
  Stuart 
  Weller 
  was 
  sent 
  into 
  the 
  region 
  and 
  

   reported 
  the 
  exact 
  sections 
  from 
  Cagen 
  Creek, 
  3 
  miles 
  north 
  of 
  

   Buck 
  Horn, 
  July 
  13, 
  1891. 
  

  

  Study 
  of 
  the 
  fossils 
  in 
  connection 
  with 
  the 
  sections 
  resulted 
  

   in 
  the 
  following 
  interpretation, 
  viz 
  : 
  

  

  1246 
  A3. 
  A 
  red 
  marble 
  —St. 
  Joe 
  marble. 
  (= 
  Eocarboniferous.) 
  

   A2. 
  Black 
  shale 
  with 
  Lingulas, 
  several 
  feet 
  thick. 
  ( 
  = 
  Eureka 
  

  

  shale.) 
  

   Al. 
  A 
  pink 
  marble 
  with 
  no 
  fossils 
  seen, 
  probably 
  the 
  Polk 
  

   Bayou 
  limestone. 
  (— 
  Trenton). 
  

  

  This 
  section 
  is 
  in 
  the 
  hollow 
  on 
  the 
  south 
  side 
  of 
  the 
  creek. 
  

   The 
  section 
  B 
  was 
  made 
  200 
  yards 
  east 
  of 
  A 
  ; 
  and 
  B' 
  = 
  A' 
  ; 
  

  

  * 
  Ann. 
  Keport, 
  1888, 
  vol. 
  iv, 
  p. 
  26. 
  

  

  