﻿40 
  Geological 
  Survey 
  of 
  Louisiana 
  [Sect. 
  

  

  known 
  or 
  supposed 
  Cretaceous 
  outcrops 
  is 
  given. 
  He 
  refers 
  to 
  

   the 
  N. 
  W. 
  — 
  S. 
  E. 
  trend 
  of 
  these 
  outcrops, 
  asHilgard 
  and 
  others 
  

   had 
  done 
  before, 
  and 
  concludes 
  "that 
  at 
  the 
  close 
  of 
  the 
  Mesozoic 
  

   time 
  enormous 
  plutonic 
  forces 
  convulsed, 
  fractured, 
  faulted 
  and 
  

   folded 
  the 
  Cretaceous 
  strata, 
  throwing 
  up 
  mountain 
  chains 
  of 
  

   vast 
  extent 
  and 
  raising 
  them 
  far 
  above 
  the 
  waters 
  of 
  the 
  Gulf." 
  

  

  The 
  lower 
  Eocene 
  beds 
  of 
  the 
  State 
  he 
  styles 
  ' 
  ' 
  lower 
  lignitic 
  ' 
  ' 
  

   in 
  contradistinction 
  to 
  similar 
  beds 
  above 
  the 
  " 
  marine 
  Claiborne 
  

   beds 
  " 
  termed 
  " 
  upper 
  lignitic." 
  

  

  It 
  should 
  be 
  borne 
  in 
  mind 
  that 
  the 
  expres.sion 
  ' 
  ' 
  lower 
  ligni- 
  

   tic," 
  as 
  here 
  used 
  is 
  simply 
  a 
  descriptive 
  term 
  and 
  in 
  no 
  way 
  

   implies 
  that 
  the 
  beds 
  are 
  equivalent 
  to 
  the 
  lower 
  Lignitic 
  beds 
  

   of 
  the 
  Alabama 
  section. 
  

  

  To 
  these 
  lignitic 
  beds 
  he 
  refers 
  the 
  outcrops 
  seen 
  along 
  the 
  

   T. 
  and 
  P. 
  R. 
  R., 
  from 
  4 
  miles 
  N. 
  W. 
  of 
  Cypress 
  station 
  to 
  

   Robeline. 
  Other 
  outcrops 
  are 
  mentioned 
  about 
  Mansfield 
  and 
  

   Shreveport. 
  

  

  " 
  Marine 
  Claiborne 
  " 
  outcrops 
  are 
  mentioned 
  from 
  S. 
  7, 
  17 
  N., 
  

   9 
  W.; 
  S. 
  22, 
  18 
  N., 
  loW.; 
  Natchitoches 
  ; 
  Capt. 
  Flair's, 
  6 
  miles 
  

   N. 
  of 
  Benton 
  ; 
  well 
  on 
  S. 
  2, 
  20 
  N., 
  13 
  W.; 
  S. 
  33, 
  16 
  N., 
  5 
  W.; 
  

   White 
  Oak 
  creek, 
  S. 
  14, 
  11 
  N., 
  5 
  W.; 
  well 
  on 
  S. 
  10, 
  10 
  N., 
  5 
  W. 
  

  

  The 
  lignitic 
  beds 
  in 
  the 
  eastern 
  part 
  of 
  Northern 
  Louisiana, 
  

   he 
  believes 
  to 
  be 
  above 
  the 
  Claiborne 
  and 
  terms 
  them 
  " 
  upper 
  

   lignitic." 
  They 
  are 
  typically 
  exposed 
  in 
  the 
  bluffs 
  and 
  R. 
  R. 
  

   cuts 
  about 
  Columbia. 
  

  

  The 
  " 
  Arcadia 
  Clays 
  " 
  according 
  to 
  this 
  author 
  are 
  bounded 
  

   on 
  the 
  south 
  "by 
  the 
  north 
  boundary 
  line 
  of 
  the 
  calcareous 
  

   marls 
  and 
  limestone 
  of 
  the 
  overlying 
  Jackson 
  and 
  Vicksburg 
  

   groups 
  of 
  Hilgard, 
  sub-parallel 
  to 
  the 
  present 
  coast 
  line 
  of 
  the 
  

   Gulf 
  of 
  Mexico. 
  They 
  cross 
  the 
  State 
  from 
  east 
  to 
  west, 
  rest- 
  

   ing 
  upon 
  the 
  deeply 
  eroded 
  surface 
  of 
  the 
  lower 
  lignitic, 
  marine 
  

   Claiborne 
  and 
  upper 
  lignitic 
  formations 
  reaching 
  northward 
  into 
  

   the 
  State 
  of 
  Arkansas, 
  westward 
  into 
  Texas, 
  and 
  are 
  bounded 
  

   in 
  the 
  east 
  by 
  the 
  flood 
  plain 
  of 
  the 
  Mississippi 
  river. 
  Their 
  

   dip 
  is 
  southwesterly, 
  though 
  on 
  account 
  of 
  the 
  erosion, 
  they 
  

   have 
  sustained, 
  the 
  covering 
  mantle 
  of 
  succeeding 
  formations 
  

   and 
  slight 
  disturbances 
  in 
  the 
  deposits, 
  it 
  is 
  frequently 
  very 
  

   ' 
  ' 
  diflQcult 
  to 
  make 
  it 
  out. 
  ' 
  ' 
  

  

  