﻿224 
  Geological 
  Survey 
  of 
  Louisiana 
  [Sect. 
  

  

  Sand 
  Pit 
  Sedioji. 
  

  

  (Elevation 
  of 
  top 
  of 
  section 
  22 
  feet 
  A. 
  T.) 
  

  

  Feet 
  In 
  

  

  1. 
  Surface 
  soil. 
  Dark 
  humus 
  stained 
  clay 
  o 
  6 
  

  

  2. 
  Mottled 
  gray 
  to 
  yellowish 
  brown 
  clay 
  2 
  6 
  

  

  3. 
  Mottled 
  gray 
  and 
  brown 
  clay 
  grading 
  below 
  into 
  

  

  finely 
  laminated 
  gray 
  clay 
  4-7 
  o 
  

  

  4. 
  Massive 
  dark 
  gray 
  clay 
  i 
  o 
  

  

  5. 
  Black 
  clay 
  with 
  iron 
  pyrite 
  1-3 
  o 
  

  

  6. 
  Black 
  shell 
  conglomerate 
  o 
  8 
  

  

  7. 
  Irregular 
  bedded 
  brown 
  to 
  white 
  sand 
  with 
  clay 
  

  

  pockets 
  and 
  traces 
  of 
  sulphur 
  2-5 
  o 
  

  

  The 
  fossils 
  in 
  layer 
  6 
  are 
  very 
  poorly 
  preserved 
  but 
  so 
  far 
  as 
  

   they 
  can 
  be 
  identified 
  indicate 
  a 
  cold 
  water 
  fauna 
  different 
  from 
  

   the 
  warm 
  water 
  fauna 
  of 
  the 
  Pliocene. 
  All 
  species 
  seem 
  to 
  be 
  

   represented 
  on 
  the 
  Gulf 
  coast 
  to-day 
  and 
  we 
  are 
  inclined 
  to 
  

   regard 
  it 
  as 
  Pleistocene 
  although 
  it 
  approaches 
  some 
  phases 
  of 
  

   the 
  Chesapeake 
  Miocene 
  rather 
  closely. 
  The 
  following 
  is 
  a 
  list 
  

   of 
  species 
  : 
  

  

  Ostrea 
  virginica-, 
  Corbula 
  sp. 
  

  

  Lithopaga, 
  cf. 
  caudigera, 
  Madra 
  sp. 
  

  

  Scapharca 
  transversa, 
  Ludna 
  sp. 
  

  

  Gnathodon 
  aineatus, 
  Venus 
  cancellata, 
  

  

  Dosinia 
  sp. 
  Semele 
  truncata, 
  

  

  Cardium 
  muricatum, 
  Fulqur 
  canaliculatuni. 
  

  

  The 
  wells. 
  — 
  A 
  fairly 
  complete 
  idea 
  of 
  the 
  substructure 
  of 
  the 
  

   island 
  maj' 
  be 
  gained 
  from 
  the 
  records 
  of 
  the 
  thirteen 
  holes 
  

   drilled 
  on 
  the 
  island. 
  Eight 
  of 
  these 
  are 
  given 
  on 
  the 
  adjoining 
  

   (Plate 
  22).* 
  In 
  hole 
  number 
  10 
  gas 
  was 
  struck 
  at 
  a 
  depth 
  of 
  

  

  *A11 
  the 
  facts 
  we 
  possess 
  regarding 
  the 
  other 
  five 
  holes 
  are 
  as 
  follows 
  : 
  

  

  2. 
  Quicksand 
  400 
  feet. 
  

  

  3. 
  Salt 
  at 
  a 
  depth 
  of 
  276 
  feet. 
  

   5. 
  200 
  feet 
  deep. 
  No 
  salt. 
  

  

  8. 
  Sand 
  175 
  feet. 
  No 
  salt. 
  

  

  9. 
  0-248. 
  No 
  record 
  248 
  feet. 
  

   248-500. 
  Salt 
  252 
  feet. 
  

   500-748. 
  Salt 
  crystals 
  248 
  feet. 
  

  

  The 
  records 
  of 
  all 
  the 
  sections 
  shown 
  on 
  Plate 
  22 
  and 
  also 
  hole 
  No. 
  9 
  were 
  

   obtained 
  from 
  Mr. 
  C. 
  B. 
  Weiser 
  of 
  the 
  Gulf 
  company. 
  The 
  others 
  are 
  from 
  

   Capt. 
  A. 
  V 
  . 
  Ivucas, 
  who 
  supterintended 
  the 
  drilling. 
  

  

  