﻿E. 
  B. 
  Branson 
  — 
  Geologic 
  Section 
  in 
  Missouri. 
  273 
  

  

  in 
  Cole 
  County 
  south 
  of 
  the 
  Missouri 
  River. 
  It 
  is 
  un- 
  

   conformable 
  on 
  Mineola, 
  Cooper, 
  Kimmswick, 
  Joachim, 
  

   St. 
  Peter, 
  and 
  Jefferson 
  City. 
  As 
  the 
  formation 
  becomes 
  

   mainly 
  sandstone 
  at 
  the 
  west 
  its 
  western 
  margin 
  of 
  out- 
  

   crop, 
  along 
  the 
  west 
  bluff 
  of 
  the 
  Missouri 
  River 
  in 
  Moni- 
  

   teau 
  County, 
  is 
  probably 
  near 
  the 
  western 
  margin 
  of 
  the 
  

   sea 
  in 
  which 
  it 
  was 
  deposited. 
  

  

  The 
  Snider 
  Creek 
  Shale 
  (Upper 
  Devonian). 
  — 
  In 
  

   Montgomery 
  and 
  Warren 
  counties 
  the 
  Callaway 
  lime- 
  

   stone 
  is 
  succeeded 
  by 
  the 
  Snider 
  Creek 
  shale, 
  which 
  is 
  

   mainly 
  shale 
  and 
  subordinately 
  limestone. 
  It 
  appears 
  

   to 
  be 
  conformable 
  on 
  the 
  Callaway 
  limestone 
  and 
  at 
  no 
  

   place 
  rests 
  on 
  other 
  formations. 
  Its 
  thickness 
  ranges 
  

   up 
  to 
  50 
  feet 
  but 
  is 
  ordinarily 
  less 
  than 
  20 
  feet. 
  Its 
  

   present 
  extent 
  is 
  formed 
  of 
  erosion 
  remnants 
  and 
  as 
  a 
  

   consequence 
  is 
  patchy. 
  It 
  can 
  not 
  be 
  traced 
  for 
  more 
  

   than 
  a 
  few 
  miles 
  at 
  any 
  place 
  and 
  its 
  total 
  extent 
  is 
  con- 
  

   fined 
  to 
  a 
  small 
  part 
  of 
  two 
  counties. 
  It 
  is 
  the 
  highest 
  

   Devonian 
  formation 
  in 
  Missouri 
  and 
  the 
  sea 
  in 
  which 
  it 
  

   formed 
  evidently 
  came 
  from 
  the 
  north. 
  G-reger 
  5 
  has 
  

   pointed 
  out 
  the 
  similarity 
  of 
  its 
  fauna 
  with 
  the 
  faunas 
  

   of 
  the 
  upper 
  Devonian 
  of 
  Iowa. 
  

  

  Interval 
  between 
  Devonian 
  and 
  Mississippian. 
  — 
  A 
  

   period 
  of 
  erosion 
  of 
  considerable 
  length 
  followed 
  the 
  

   deposition 
  of 
  the 
  Snider 
  Creek. 
  In 
  many 
  places 
  Devo- 
  

   nian 
  strata 
  were 
  tilted 
  a 
  few 
  degrees 
  and 
  the 
  folds 
  

   eroded 
  to 
  an 
  even 
  surface 
  before 
  Mississippian 
  rocks 
  

   were 
  deposited 
  and 
  at 
  no 
  place 
  has 
  the 
  writer 
  found 
  

   Mississippian 
  conformable 
  on 
  Devonian. 
  The 
  evidences 
  

   of 
  unconformity 
  are 
  : 
  old 
  valleys 
  in 
  the 
  Devonian; 
  joints 
  

   in 
  the 
  Devonian 
  rocks 
  filled 
  with 
  Mississippian 
  sedi- 
  

   ments 
  ; 
  caves 
  in 
  Devonian 
  rocks 
  partially 
  filled 
  with 
  Mis- 
  

   sissippian 
  sediments; 
  overlap 
  of 
  earliest 
  Mississippian 
  

   sediments 
  over 
  various 
  Devonian 
  formations; 
  a 
  com- 
  

   plete 
  break 
  in 
  the 
  faunas. 
  

  

  Mississippian. 
  

  

  The 
  Sylamore 
  Sandstone 
  (Basal 
  Mississippian). 
  — 
  The 
  

   Mississippian 
  seas 
  advanced 
  over 
  a 
  surface 
  of 
  gentle 
  

   relief, 
  with 
  occasional 
  valleys 
  30 
  to 
  60 
  feet 
  deep, 
  and 
  

   deposited 
  the 
  Sylamore 
  sandstone, 
  which 
  varies 
  in 
  thick- 
  

   ness 
  up 
  to 
  70 
  feet. 
  This 
  averages 
  little 
  more 
  than 
  a 
  foot 
  

   in 
  thickness 
  and 
  the 
  greater 
  thicknesses 
  occur 
  mainly 
  in 
  

  

  6 
  This 
  Journal, 
  vol. 
  27, 
  pp. 
  375-378. 
  

  

  