﻿26o 
  Geological 
  Survey 
  of 
  Louisiana 
  [Sect 
  

  

  time. 
  The 
  main 
  folding 
  and 
  faulting 
  which 
  occurred 
  in 
  the 
  

   Pleistocene 
  was 
  followed 
  by 
  the 
  depression 
  of 
  the 
  whole 
  costal 
  

   region 
  and 
  the 
  deposition 
  of 
  the 
  upper 
  j^ellow 
  clays. 
  During 
  the 
  

   succeeding 
  high 
  level 
  period 
  the 
  deep 
  channels 
  of 
  the 
  costal 
  

   rivers 
  were 
  excavated 
  and 
  the 
  lake 
  valleys 
  formed 
  on 
  the 
  islands. 
  

   The 
  subsidence 
  which 
  followed 
  has 
  continued 
  to 
  the 
  present 
  day. 
  

  

  That 
  the 
  immediate 
  shore 
  of 
  the 
  Gulf 
  should 
  have 
  been 
  the 
  

   scene 
  of 
  orographic 
  movements 
  in 
  Pleistocene 
  time 
  ma}'' 
  at 
  first 
  

   appear 
  a 
  little 
  startling 
  but 
  there 
  is 
  no 
  reason 
  why 
  it 
  should 
  not 
  

   be 
  so 
  and 
  every 
  reason 
  why 
  it 
  should. 
  The 
  great 
  sedimentary 
  

   deposits 
  which 
  have 
  been 
  forming 
  along 
  the 
  Gulf 
  shore 
  in 
  recent 
  

   time 
  would 
  tend 
  to 
  disturb 
  its 
  equilibrium. 
  The 
  extent 
  of 
  these 
  

   recent 
  deposits 
  is 
  shown 
  in 
  the 
  Galveston 
  well 
  section 
  which 
  at 
  

   a 
  depth 
  of 
  2,920 
  feet 
  had 
  not 
  penetrated 
  the 
  Upper 
  Miocene. 
  

   1,500 
  feet 
  of 
  this 
  material 
  is 
  above 
  strata 
  known 
  to 
  be 
  Upper 
  

   Tertiar5^* 
  

  

  Age 
  of 
  the 
  salt 
  deposit. 
  — 
  No 
  data 
  bearing 
  directly 
  on 
  the 
  age 
  of 
  

   the 
  salt 
  deposit 
  have 
  yet 
  been 
  obtained. 
  No 
  fossils 
  older 
  than 
  

   Pleistocene 
  have 
  been 
  found 
  m 
  situ 
  in 
  the 
  neighborhood 
  of 
  the 
  

   salt. 
  The 
  gravel 
  beds 
  which 
  overlie 
  the 
  salt 
  are 
  of 
  decidedly 
  

   uncertain 
  date. 
  If 
  we 
  accept 
  the 
  generally 
  received 
  opinion 
  of 
  

   the 
  age 
  of 
  the 
  southern 
  gravel 
  beds 
  they 
  are 
  Lafayette 
  or 
  late 
  

   Pleiocene. 
  This 
  would 
  make 
  the 
  salt 
  bed 
  pre-Pleistocene. 
  

  

  The 
  only 
  other 
  data 
  we 
  have 
  bearing 
  on 
  the 
  age 
  of 
  this 
  deposit 
  

   are 
  the 
  salines 
  of 
  northern 
  Louisiana. 
  Darby 
  first 
  called 
  atten- 
  

   tion 
  to 
  the 
  similarity 
  between 
  the 
  salt 
  springs 
  on 
  Petite 
  Anse 
  

   and 
  those 
  north 
  of 
  Red 
  River. 
  f 
  Hilgard 
  noticed 
  the 
  same 
  

   resemblance 
  is 
  his 
  reconnaissance 
  of 
  Louisiana 
  in 
  1869 
  and 
  con- 
  

   ceived 
  the 
  idea 
  of 
  a 
  Cretaceous 
  ridge 
  or 
  backbone 
  with 
  several 
  

   peaks 
  now 
  represented 
  by 
  outcrops. 
  These 
  salines 
  are 
  in 
  many 
  

   cases 
  associated 
  with 
  hard 
  prystalline 
  limestone 
  showing, 
  

  

  * 
  Preliminary 
  Report 
  on 
  the 
  Organic 
  Remains 
  Obtained 
  from 
  the 
  Deep 
  

   Well 
  at 
  Galveston 
  together 
  with 
  Conclusions 
  Respecting 
  the 
  Age 
  of 
  the 
  

   Various 
  Formations 
  ; 
  Penetrated 
  by 
  G. 
  D. 
  Harris, 
  4th 
  An. 
  Rept. 
  Texas 
  Geol. 
  

   Surv., 
  pp. 
  117-119 
  1893. 
  

  

  f 
  The 
  Emigrant's 
  Guide 
  to 
  the 
  western 
  and 
  southwestern 
  States, 
  etc., 
  

   New 
  York, 
  1818, 
  p. 
  86. 
  He 
  says, 
  "From 
  its 
  proximity, 
  this 
  spring, 
  has 
  

   been 
  considered 
  as 
  merely 
  a 
  drain 
  of 
  the 
  sea, 
  but 
  on 
  inspection, 
  it 
  has 
  all 
  

   the 
  common 
  features 
  of 
  the 
  salt 
  springs 
  found 
  north 
  of 
  Red 
  River." 
  

  

  