﻿Fossils 
  in 
  strata 
  of 
  Carboniferous 
  Age. 
  95 
  

  

  been 
  supposed 
  to 
  be 
  equivalent 
  to 
  the 
  " 
  black 
  shales 
  " 
  of 
  Ten- 
  

   nessee 
  and 
  of 
  Devonian 
  age. 
  

  

  More 
  fossils 
  were 
  collected 
  and 
  the 
  Arkansas 
  geologists 
  

   examined 
  the 
  locality 
  with 
  special 
  care 
  but 
  with 
  the 
  result 
  of 
  

   confirming 
  the 
  singleness 
  of 
  the 
  horizon 
  from 
  which 
  the 
  fos- 
  

   sils 
  came 
  and 
  the 
  certainty 
  of 
  the 
  duplicity 
  of 
  the 
  testimony 
  

   of 
  the 
  fossils 
  themselves. 
  Finally, 
  Drs. 
  Branner, 
  Penrose 
  and 
  I 
  

   went 
  together 
  and 
  examined 
  the 
  locality 
  with 
  special 
  care 
  and 
  

   sent 
  in 
  a 
  collector, 
  Mr. 
  Weller, 
  to 
  make 
  full 
  collections 
  of 
  the 
  

   fossils 
  of 
  the 
  neighborhood, 
  and 
  the 
  materials 
  are 
  now 
  being 
  

   elaborated 
  for 
  a 
  full 
  report 
  of 
  the 
  fauna. 
  On 
  account 
  of 
  the 
  

   importance 
  of 
  the 
  facts 
  this 
  preliminary 
  announcement 
  is 
  made. 
  

  

  The 
  geological 
  age 
  of 
  the 
  Spring 
  Creek 
  limestone 
  is 
  estab- 
  

   lished 
  to 
  be 
  younger 
  than 
  the 
  Batesville 
  sandstone 
  and 
  older 
  

   than 
  the 
  Boone 
  chert, 
  of 
  the 
  Arkansas 
  survey 
  nomenclature, 
  

   which 
  makes 
  it 
  equivalent 
  to 
  the 
  Warsaw 
  or 
  St. 
  Louis 
  lime- 
  

   stone 
  of 
  Missouri 
  and 
  the 
  Mississippi 
  Valley 
  sections 
  in 
  general. 
  

   Three 
  kinds 
  of 
  evidence 
  confirm 
  this 
  determination 
  : 
  The 
  

   stratigraphy 
  of 
  the 
  immediate 
  neighborhood 
  of 
  Spring 
  Creek, 
  

   and 
  second 
  the 
  correlation 
  of 
  the 
  fauna 
  with 
  faunas 
  of 
  the 
  

   same 
  general 
  region 
  of 
  higher 
  and 
  lower 
  horizons, 
  and 
  third 
  

   the 
  comparison 
  of 
  the 
  species 
  of 
  the 
  fauna 
  with 
  those 
  of 
  a 
  

   different 
  geological 
  province 
  whose 
  age 
  is 
  established 
  on 
  inde- 
  

   pendent 
  evidence. 
  The 
  stratigraphical 
  evidence 
  is 
  as 
  follows 
  : 
  

  

  The 
  locality 
  is 
  in 
  the 
  northern 
  part 
  of 
  Arkansas, 
  geologically 
  

   on 
  the 
  southern 
  slope 
  of 
  the 
  Ozark 
  uplift, 
  which 
  centers 
  in 
  

   southeastern 
  Missouri, 
  where 
  the 
  upper 
  paleozoic 
  terranes 
  lie 
  

   with 
  a 
  general 
  dip 
  southward 
  and 
  southwestward, 
  with 
  thin 
  

   upper 
  edges 
  graded 
  toward 
  the 
  north 
  so 
  that 
  outcrops 
  are 
  of 
  

   older 
  and 
  older 
  rocks 
  on 
  passing 
  northeastward 
  from 
  Spring 
  

   Creek, 
  a 
  point 
  a 
  mile 
  or 
  so 
  west 
  of 
  Batesville. 
  There 
  is 
  a 
  fault 
  

   near 
  the 
  point 
  where 
  the 
  fossils 
  come 
  from 
  running 
  north- 
  

   easterly, 
  the 
  southeasterly 
  mass 
  has 
  fallen 
  below 
  the 
  north- 
  

   westerly 
  mass. 
  The 
  Spring 
  Creek 
  limestone 
  is 
  on 
  the 
  northwest 
  

   side 
  of 
  the 
  fault 
  hence 
  the 
  occurrence 
  of 
  the 
  Devonian 
  types 
  

   cannot 
  be 
  explained 
  as 
  having 
  been 
  caught 
  in 
  a 
  fault, 
  since 
  the 
  

   other 
  side 
  of 
  the 
  faulted 
  rock 
  has 
  been 
  dragged 
  down, 
  leaving 
  

   more 
  recent 
  and 
  not 
  older 
  rocks 
  at 
  the 
  same 
  horizon 
  on 
  the 
  

   opposite 
  side. 
  

  

  The 
  strata 
  underlying 
  the 
  Spring 
  »C 
  reek 
  limestone 
  was 
  shown 
  

   to 
  be 
  the 
  Boone 
  chert 
  (= 
  Keokuk-Burlington 
  of 
  Missouri, 
  Illi- 
  

   nois, 
  Iowa, 
  etc.). 
  The 
  Batesville 
  sandstone 
  above 
  it 
  contains 
  a 
  

   fauna 
  closely 
  like 
  the 
  fauna 
  of 
  the 
  St. 
  Louis 
  limestones 
  in 
  some 
  

   of 
  its 
  species. 
  At 
  Mountain 
  view 
  some 
  of 
  the 
  same 
  species 
  

   are 
  reported 
  from 
  a 
  similar 
  stratigraphical 
  position. 
  In 
  its 
  more 
  

   western 
  exposures, 
  according 
  to 
  the 
  interpretation 
  of 
  the 
  Arkan- 
  

   sas 
  geologists, 
  the 
  same 
  interval 
  is 
  occupied 
  by 
  the 
  Fayett- 
  

  

  