﻿I] 
  Historical 
  Review 
  : 
  Second 
  Period 
  23 
  

  

  Owen.^ 
  — 
  Dr. 
  Richard 
  Owen 
  of 
  Indiana 
  visited 
  Petite 
  Ansa 
  

   in 
  the 
  latter 
  part 
  of 
  1865. 
  After 
  a 
  hast}- 
  examination 
  he 
  showed 
  

   that 
  the 
  island 
  was 
  composed 
  of 
  sedimentary 
  material 
  and 
  con- 
  

   cluded 
  that 
  it 
  was 
  a 
  wind 
  and 
  wave 
  formed 
  dune 
  similar 
  to 
  those 
  

   on 
  the 
  southern 
  shore 
  of 
  Lake 
  Michigan. 
  

  

  SECOND 
  PERIOD 
  

   Reconnaissance 
  Period, 
  1867-1892 
  

  

  Hilgard. 
  — 
  In 
  1867, 
  Hilgard, 
  under 
  the 
  direction 
  of 
  the 
  Smith- 
  

   sonian 
  Institution 
  made 
  a 
  trip 
  down 
  the 
  Mississippi 
  and 
  to 
  the 
  

   central 
  three 
  of 
  the 
  Five 
  Islands. 
  The 
  preliminary 
  report 
  on 
  this 
  

   reconnaissance 
  appeared 
  in 
  i869.;{: 
  At 
  that 
  time 
  he 
  regarded 
  the 
  

   rock 
  salt 
  as 
  having 
  been 
  formed 
  by 
  evaporation 
  in 
  a 
  lagoon 
  or 
  

   series 
  of 
  lagoons 
  and 
  as 
  resting 
  in 
  a 
  bed 
  of 
  marine 
  clays 
  of 
  

   early 
  Quaternary 
  age. 
  He 
  considered 
  the 
  hills 
  as 
  simply 
  the 
  

   accidents 
  of 
  differential 
  erosion. 
  

  

  The 
  same 
  year 
  he 
  published 
  in 
  the 
  American 
  Journal 
  of 
  Science 
  

   the 
  " 
  Summary 
  Results 
  of 
  a 
  late 
  Geological 
  Reconnaissance 
  of 
  

   Louisiana." 
  It 
  was 
  based 
  on 
  operations 
  largely 
  in 
  the 
  western 
  

   part 
  of 
  the 
  State 
  and 
  was 
  made 
  under 
  the 
  auspices 
  of 
  the 
  New 
  

   Orleans 
  Academy 
  of 
  Sciences. 
  Thirty 
  days 
  only 
  were 
  allowe4 
  

   for 
  the 
  field 
  work. 
  New 
  Iberia' 
  Bayou 
  Chicot, 
  Lake 
  Charles, 
  

   Sabinetown, 
  Many, 
  Mansfield, 
  Coushatta 
  Chute, 
  Winnfield 
  and 
  

   Harrisonburg 
  were 
  passed 
  through 
  en 
  route. 
  

  

  He 
  reviews 
  the 
  various 
  terranes 
  of 
  the 
  State, 
  commencing 
  

   with 
  the 
  younger 
  or 
  " 
  Port 
  Hudson 
  group 
  " 
  and 
  notices 
  in 
  turn 
  

   the 
  other 
  groups, 
  viz.: 
  the 
  "Orange 
  Sand 
  formation," 
  the 
  

   ' 
  ' 
  Grand 
  Gulf 
  group 
  ; 
  ' 
  ' 
  the 
  ' 
  ' 
  Vicksburg 
  group 
  ; 
  ' 
  ' 
  the 
  ' 
  ' 
  Mansfield 
  

   group 
  ;" 
  and 
  then 
  takes 
  up 
  and 
  discusses 
  the 
  salines 
  of 
  North 
  

   Louisiana 
  and 
  the 
  artesian 
  wells 
  of 
  Calcasieu. 
  

  

  The 
  Port 
  Hudson 
  group 
  is 
  said 
  to 
  be 
  of 
  considerable 
  thickness, 
  

   600 
  feet 
  or 
  more 
  beneath 
  New 
  Orleans 
  and 
  to 
  extend 
  up 
  the 
  

  

  *0n 
  the 
  Rock 
  Salt 
  at 
  New 
  Iberia, 
  Louisiana 
  by 
  Prof. 
  Richard 
  Owen 
  

   Trans. 
  Acad. 
  Sci., 
  St. 
  Louis, 
  vol. 
  2, 
  pp. 
  250-252, 
  1868. 
  Abstract, 
  Am. 
  Jour. 
  

   Sci., 
  2d 
  Series, 
  vol. 
  42, 
  pp. 
  120-123, 
  1868. 
  

  

  |Amer. 
  Jour. 
  Sci., 
  2d. 
  ser., 
  vol. 
  47, 
  pp. 
  78-88, 
  1869; 
  also 
  Am. 
  Assoc. 
  

   Adv. 
  Sci., 
  Proc, 
  vol. 
  17, 
  pp. 
  327-340. 
  

  

  