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  GEOLOGY. 
  

  

  3. 
  Marine 
  Marl 
  — 
  such 
  as 
  that 
  at 
  Vicksburg 
  — 
  varying 
  

   somewhat 
  in 
  character 
  in 
  different 
  localities, 
  but 
  all 
  in- 
  

   cluding 
  marine 
  shells, 
  with 
  specific 
  distinctions, 
  but 
  of 
  

   allied 
  genera. 
  

  

  4. 
  Gypseous 
  Marl 
  — 
  such 
  as 
  those 
  near 
  Clinton 
  and 
  

   Jackson, 
  in 
  Hinds 
  County 
  — 
  containing 
  crystallized 
  gyp- 
  

   sum 
  or 
  selenite, 
  and 
  resembling 
  somewhat 
  in 
  appearance 
  

   the 
  chocolate-colored 
  green-sand 
  marls 
  described 
  in 
  New 
  

   Jersey. 
  

  

  5. 
  The 
  tertiary 
  green-sand 
  marl 
  — 
  as 
  existing 
  at 
  Jack- 
  

   son 
  — 
  containing 
  an 
  immense 
  quantity 
  of 
  shells 
  of 
  the 
  

   eocene 
  period, 
  differing 
  from 
  those 
  at 
  Vicksburg, 
  and 
  in- 
  

   cluding 
  species 
  that 
  are 
  new 
  and 
  undescribed. 
  

  

  6. 
  The 
  Indurated 
  Marl 
  — 
  the 
  white 
  or 
  rotten 
  limestone 
  

   so 
  called, 
  found 
  chiefly 
  in 
  the 
  prairie 
  region 
  — 
  of 
  a 
  pale 
  

   blue 
  color 
  when 
  first 
  dug 
  out 
  in 
  its 
  moist 
  state, 
  below 
  

   the 
  surface, 
  but 
  which 
  bleaches 
  and 
  crumbles 
  to 
  powder 
  

   by 
  exposure 
  to 
  atmospheric 
  action. 
  

  

  7. 
  The 
  Cretaceous 
  Marls 
  of 
  the 
  Tombigbee 
  and 
  its 
  

   tributaries, 
  varying 
  in 
  character, 
  and 
  containing, 
  in 
  

   some 
  of 
  the 
  beds, 
  more 
  or 
  less 
  green-sand, 
  and 
  charac- 
  

   terized 
  by 
  fossils 
  of 
  the 
  cretaceous 
  group. 
  

  

  It 
  will 
  be 
  seen, 
  in 
  the 
  chapter 
  on 
  analysis, 
  that 
  few 
  of 
  

   these 
  marls 
  have 
  been 
  chemically 
  examined, 
  and 
  the 
  

   reasons 
  have 
  before 
  been 
  stated. 
  As 
  yet, 
  they 
  have 
  re- 
  

   ceived 
  little 
  attention 
  from 
  our 
  planters; 
  and 
  I 
  can 
  

   learn 
  of 
  very 
  few 
  experiments 
  which 
  have 
  been 
  made 
  

   with 
  them. 
  

  

  As 
  these 
  will 
  probably 
  become 
  of 
  much 
  value 
  here- 
  

   after, 
  and 
  exert 
  an 
  important 
  influence 
  upon 
  the 
  agri- 
  

   cultural 
  prosperity 
  of 
  the 
  State, 
  it 
  will 
  not 
  be 
  considered 
  

   out 
  of 
  place 
  to 
  quote, 
  from 
  Professor 
  Rogers's 
  report 
  on 
  

   New 
  Jersey, 
  a 
  description 
  of 
  some 
  of 
  the 
  properties, 
  

   and 
  the 
  value 
  and 
  effect 
  of 
  some 
  of 
  these 
  marls 
  in 
  that 
  

  

  