﻿228 
  

  

  Geological 
  Survey 
  of 
  Louisiana 
  

  

  [Sect. 
  

  

  Section 
  of 
  hole 
  No. 
  13. 
  — 
  Fossils 
  were 
  found 
  in 
  two 
  layers 
  of 
  hole 
  

   No. 
  13 
  which 
  was 
  sunk 
  a 
  short 
  distance 
  north 
  of 
  Willow 
  pond. 
  

  

  Section 
  of 
  Hole 
  No. 
  13. 
  

   No. 
  Depths 
  Feet 
  

  

  1 
  . 
  o-ioo 
  Clay 
  100 
  

  

  2. 
  100-130 
  Sand 
  30 
  

  

  3. 
  130-135 
  Clay 
  and 
  shells 
  5 
  

  

  4. 
  135-145 
  Sand 
  10 
  

  

  5 
  . 
  145-150 
  Hard 
  clay 
  and 
  shells 
  5 
  

  

  6. 
  1 
  50-200 
  Sand 
  5© 
  

  

  7. 
  200-216 
  Very 
  hard 
  gravel 
  16 
  

  

  8. 
  216-260 
  Hard 
  sand 
  and 
  gravel 
  54 
  

  

  J" 
  

  

  ^00 
  

  

  400 
  

  

  JOO 
  

  

  600 
  

  

  (DOC 
  

  

  T 
  Z 
  ™ 
  Z 
  

  

  s- 
  n 
  - 
  ^ 
  ^ 
  at 
  

  

  « 
  O 
  S 
  T 
  J 
  I 
  

  

  Galena, 
  sphalerite 
  and 
  barite 
  bowlders 
  

  

  Salt 
  

  

  feef 
  Jor> 
  

  

  too 
  Soo 
  

  

  7000 
  ^ 
  rsoo 
  

  

  /400 
  

  

  /*r<7 
  

  

  iSoo 
  

  

  2!00 
  ^s 
  ^-/"O 
  

  

  Fig, 
  6— 
  Section 
  cross 
  Belle 
  Isle, 
  along 
  line 
  A-B, 
  pi. 
  20. 
  

  

  Conclusions. 
  — 
  All 
  the 
  data 
  collected, 
  while 
  throwing 
  little 
  or 
  no 
  

   light 
  on 
  the 
  age 
  of 
  the 
  salt 
  deposit 
  and 
  further 
  complicating 
  the 
  

   questions 
  involved 
  by 
  the 
  introduction 
  of 
  a 
  deposit 
  of 
  galena, 
  

   baryte 
  and 
  sphalerite 
  have 
  afforded 
  rather 
  satisfactory 
  evidence 
  

   on 
  the 
  manner 
  of 
  the 
  formation 
  of 
  Belle 
  Isle. 
  A 
  map 
  showing 
  

   the 
  contour 
  of 
  the 
  salt, 
  constructed 
  on 
  data 
  furnished 
  by 
  the 
  

   drill 
  holes, 
  shows 
  an 
  oblong 
  dome-shaped 
  mass, 
  longest 
  along 
  its 
  

   northeast 
  and 
  southwest 
  axis, 
  having 
  just 
  the 
  same 
  trend 
  as 
  the 
  

   hills 
  ; 
  but 
  differing 
  from 
  the 
  hills 
  in 
  the 
  fact 
  that 
  the 
  dome 
  of 
  

   the 
  salt 
  is 
  situated 
  on 
  the 
  northeast 
  of 
  the 
  island. 
  (See 
  plate 
  24. 
  ) 
  

  

  The 
  shaft 
  shows 
  clearly 
  that 
  this 
  dome 
  shape 
  is 
  due 
  to 
  uplift 
  

   and 
  not 
  erosion. 
  When 
  the 
  salt 
  was 
  first 
  struck 
  in 
  the 
  shaft 
  it 
  

  

  