﻿116 
  

  

  R. 
  T. 
  Hill 
  — 
  Reconnaissance 
  of 
  the 
  

  

  the 
  mountain 
  region 
  south 
  of 
  the 
  coal 
  fields 
  can 
  be 
  said 
  liter- 
  

   ally 
  to 
  be 
  standing 
  vertically 
  as 
  shown 
  in 
  the 
  figures. 
  

   This 
  system 
  of 
  folding 
  is 
  complicated 
  and 
  the 
  writer 
  has 
  not 
  

   had 
  time 
  for 
  the 
  minute 
  study 
  necessary 
  to 
  interpret 
  it. 
  In 
  gen- 
  

   eral, 
  two 
  great 
  trends 
  or 
  strikes 
  are 
  conspicuous, 
  the 
  first 
  and 
  

   oldest 
  is 
  about 
  25° 
  south 
  of 
  west 
  ; 
  this 
  is 
  frequently 
  dislocated 
  

   by 
  an 
  apparently 
  later 
  movement 
  resulting 
  in 
  northeast 
  and 
  

   southwest 
  trends, 
  all 
  of 
  which 
  are 
  

   accompanied 
  by 
  overlapping 
  and 
  

   lack 
  of 
  continuity.* 
  The 
  direction 
  

   of 
  the 
  folds 
  has 
  a 
  marked 
  effect 
  on 
  

   the 
  political 
  features 
  of 
  the 
  region, 
  

   all 
  lines 
  of 
  transportation 
  and 
  public 
  

   highways 
  practically 
  following 
  the 
  

   valleys 
  of 
  erosion 
  in 
  the 
  trend 
  of 
  

   the 
  folds. 
  

  

  The 
  proof 
  of 
  two 
  great 
  disloca- 
  

   tions 
  of 
  the 
  Carboniferous 
  strata 
  is 
  

   found 
  in 
  the 
  mountains 
  north 
  of 
  

   Atoka 
  and 
  in 
  Limestone 
  ridge 
  

   where 
  the 
  vertical 
  folds 
  of 
  the 
  first 
  

   epoch 
  are 
  deflected 
  by 
  S-shaped 
  

   dislocations 
  into 
  the 
  southeast 
  

   course. 
  

  

  Of 
  the 
  many 
  illustrations 
  of 
  this 
  

   folding 
  one 
  of 
  the 
  finest 
  is 
  found 
  in 
  

   the 
  peculiar 
  limestone 
  ridge 
  which 
  

   extends 
  from 
  near 
  Lehigh 
  to 
  Lime- 
  

   stone 
  Gap 
  and 
  eastward. 
  This 
  is 
  

   the 
  principal 
  limestone 
  stratum 
  of 
  

   the 
  Carboniferous 
  system 
  ; 
  it 
  occurs 
  

   at 
  the 
  base 
  of 
  Mr. 
  Chance's 
  section. 
  

   It 
  consists 
  of 
  about 
  200 
  feet 
  of 
  

   massive 
  blue 
  limestone 
  and 
  dolomite 
  

   standing 
  vertically. 
  From 
  near 
  

   Wapenucka 
  via. 
  Lehigh 
  to 
  Lime- 
  

   stone 
  Gap, 
  thence 
  eastward 
  to 
  the 
  

   St. 
  Louis 
  and 
  San 
  Francisco 
  railroad, 
  it 
  forms 
  a 
  sharp 
  ridge 
  

   rising 
  100 
  feet 
  above 
  the 
  adjacent 
  valleys, 
  a 
  plan 
  and 
  cross 
  

   section 
  of 
  which 
  are 
  given 
  in 
  the 
  accompanying 
  figure 
  (3). 
  

  

  The 
  Missouri, 
  Kansas 
  and 
  Texas 
  railroad, 
  between 
  String- 
  

   town 
  and 
  Limestone 
  Gap, 
  follows 
  the 
  valley 
  east 
  of 
  this 
  ridge 
  ;. 
  

   at 
  the 
  latter 
  place 
  a 
  tributary 
  of 
  the 
  Red 
  river 
  has 
  cut 
  through 
  

   the 
  ridge 
  which, 
  from 
  this 
  point, 
  trends 
  eastward 
  as 
  shown 
  in 
  

  

  * 
  Dr. 
  John 
  C. 
  Branner, 
  on 
  page 
  30, 
  vol. 
  i. 
  of 
  his 
  report, 
  has 
  previously 
  expressed 
  

   an 
  opinion 
  that 
  in 
  Arkansas 
  these 
  folds 
  are 
  of 
  overlapping 
  rather 
  than 
  of 
  con- 
  

   tinuous 
  strike, 
  as 
  stated 
  by 
  Comstock 
  in 
  the 
  same 
  volume. 
  

  

  Limestone 
  Ridge, 
  showing 
  

   mountain 
  folds. 
  

  

  