﻿11] 
  General 
  Geology 
  : 
  Jackson 
  Eocene 
  91 
  

  

  Montgomery 
  . 
  — 
  This 
  is 
  already 
  a 
  classic 
  locality 
  in 
  I^ouisiana 
  

   geology. 
  (See 
  under 
  Historic 
  Review.) 
  The 
  accompanying 
  

   illustration 
  shows 
  well 
  the 
  general 
  appearance 
  of 
  the 
  most 
  

   important 
  outcrop 
  in 
  this 
  region. 
  

  

  The 
  following 
  beds 
  are 
  exposed 
  : 
  

  

  8. 
  Orange 
  sands 
  : 
  5-50 
  ft. 
  

  

  7. 
  The 
  above 
  grade 
  downward 
  into 
  pebble 
  beds 
  5 
  ft. 
  

  

  6. 
  Light 
  sands 
  3 
  ft. 
  

  

  5. 
  Sands, 
  slightly 
  lignitic 
  5 
  ft. 
  

  

  4. 
  As 
  5, 
  separated 
  by 
  clay 
  layer 
  8 
  ft. 
  

  

  3. 
  Thin 
  light 
  sandy 
  clay 
  , 
  

  

  2. 
  Bluish 
  marl, 
  fossiliferous 
  5 
  ft. 
  

  

  I. 
  Lignitiferous 
  clays 
  15 
  ft. 
  

  

  Large 
  collections 
  were 
  made 
  at 
  this 
  locality 
  and 
  will 
  be 
  

   reported 
  upon 
  next 
  year. 
  

  

  Owing 
  to 
  a 
  very 
  heavy 
  deposit 
  of 
  Lafayette 
  material 
  over 
  these 
  

   Jackson 
  beds 
  the 
  influence 
  of 
  the 
  latter 
  upon 
  the 
  soils 
  of 
  the 
  

   region 
  is 
  greatly 
  diminished. 
  Towards 
  Wheeling, 
  on 
  the 
  east 
  

   side 
  of 
  Nantaches 
  bayou, 
  very 
  extensive 
  deposits 
  of 
  ferruginous 
  

   sandstone 
  and 
  sands 
  were 
  observed. 
  The 
  hills 
  are 
  50 
  to 
  150 
  

   feet 
  in 
  height 
  above 
  the 
  Bayou. 
  The 
  ravines, 
  although 
  numer- 
  

   ous, 
  seem 
  to 
  show 
  no 
  traces 
  of 
  fossil 
  remains. 
  The 
  soil 
  of 
  the 
  

   hills 
  is 
  excessively 
  sandy. 
  Gravel 
  layers 
  are 
  numerous, 
  occur- 
  

   ring 
  above 
  the 
  heavy 
  sandstone 
  ledges, 
  and 
  below 
  the 
  gray 
  sands 
  

   of 
  the 
  hills. 
  

  

  Tancock' 
  s 
  prairie. 
  — 
  Just 
  south 
  of 
  Ben 
  creek 
  or 
  the 
  northern 
  

   edge 
  of 
  Tancock's 
  prairie 
  many 
  specimens 
  of 
  Ostrea 
  tri^onalis 
  are 
  

   scattered 
  over 
  the 
  ground. 
  The 
  limestone 
  concretions 
  which 
  

   accompany 
  this 
  outcrop 
  contain 
  in 
  addition 
  to 
  other 
  forms 
  very 
  

   large 
  specimens 
  of 
  Harninea 
  grandis. 
  These 
  with 
  other 
  speci- 
  

   mens 
  collected 
  have 
  proven 
  the 
  Jackson 
  age 
  of 
  the 
  locality. 
  

   Hilgard 
  refers 
  this 
  to 
  the 
  Vicksburg.* 
  

  

  Tullos. 
  — 
  This 
  station 
  is 
  in 
  a 
  Jackson 
  prairie. 
  In 
  light 
  grayish 
  

   sandy 
  clay 
  in 
  the 
  railroad 
  cuts 
  there 
  are 
  many 
  calcareous 
  concre- 
  

   tions. 
  In 
  the 
  bottom 
  of 
  some 
  of 
  the 
  wash-outs 
  by 
  the 
  side 
  of 
  

   the 
  track 
  a 
  bluish 
  clay 
  appears. 
  

  

  *Am. 
  Jour. 
  Sci., 
  2d 
  series, 
  vol. 
  47, 
  1869, 
  p. 
  340 
  ; 
  Supl. 
  and 
  Final 
  Report 
  of 
  

   a 
  Geol. 
  Record 
  of 
  La., 
  p. 
  33. 
  

  

  