﻿194 
  Geological 
  Survey 
  of 
  Louisiana 
  [Sect. 
  

  

  the 
  surface 
  of 
  the 
  ground 
  and 
  forces 
  out 
  some 
  of 
  the 
  underlying 
  

   mud. 
  The 
  objection 
  to 
  this 
  theory 
  lies 
  in 
  the 
  great 
  range 
  of 
  

   these 
  mounds 
  in 
  altitude 
  and 
  over 
  beds 
  of 
  different 
  ages. 
  

  

  Scattered 
  through 
  all 
  the 
  beds 
  of 
  Louisiana, 
  from 
  the 
  lowest 
  

   Tertiary 
  to 
  the 
  most 
  recent, 
  there 
  are 
  large 
  amounts 
  of 
  vegetable 
  

   matter 
  mixed 
  with 
  beds 
  of 
  sands 
  and 
  clays. 
  The 
  decomposition 
  

   of 
  this 
  vegetable 
  matter 
  forms 
  gas 
  and 
  if 
  this 
  gas 
  in 
  its 
  passage 
  

   to 
  the 
  surface 
  passes 
  through 
  a 
  bed 
  of 
  sand 
  it 
  will 
  probably 
  carry 
  

   to 
  the 
  surface 
  some 
  of 
  the 
  sand 
  and 
  so 
  form 
  a 
  little 
  mound. 
  Such 
  

   cones 
  are 
  now 
  forming 
  near 
  the 
  sulphur 
  well 
  at 
  Lake 
  Charles 
  and 
  

   formation 
  of 
  the 
  mudlumps 
  seems 
  to 
  be 
  very 
  analogous. 
  This 
  

   theory 
  was 
  first 
  originated 
  for 
  the 
  mud-lumps 
  by 
  Siddell 
  * 
  and 
  

   and 
  applied 
  to 
  the 
  mounds 
  bj'' 
  Hopkins. 
  f 
  Clendenin 
  supple- 
  

   ments 
  this 
  explanation 
  with 
  a 
  hypothetical 
  formation 
  of 
  the 
  gas 
  

   vents 
  by 
  earthquakes. 
  The 
  theory 
  of 
  the 
  gas 
  origin 
  of 
  the 
  

   mounds 
  seems 
  to 
  be 
  more 
  nearly 
  supported 
  by 
  the 
  observed 
  facts 
  

   than 
  any 
  other 
  theory 
  yet 
  advanced. 
  But 
  the 
  exact 
  relation 
  

   between 
  the 
  water 
  and 
  the 
  gas, 
  which 
  issue 
  from 
  the 
  mounds 
  

   now 
  forming, 
  has 
  never 
  been 
  fully 
  worked 
  out. 
  It 
  may 
  be 
  that 
  

   the 
  gas 
  merely 
  accompanies 
  the 
  water 
  instead 
  of 
  the 
  water 
  

   accompanying 
  the 
  gas. 
  

  

  The 
  Indian 
  garden-mound 
  theory 
  is 
  probably 
  one 
  of 
  the 
  most 
  

   hypothetical 
  yet 
  advanced. 
  Nadaillac 
  in 
  his 
  Prehistoric 
  America, 
  

   p. 
  182, 
  says: 
  "Between 
  Red 
  river 
  and 
  the 
  Wichita 
  they 
  (the 
  

   Indian 
  garden-beds) 
  can 
  be 
  counted 
  by 
  thousands. 
  According 
  

   to 
  Forshey, 
  who 
  described 
  them 
  to 
  the 
  New 
  Orleans 
  Academy 
  of 
  

   Sciences, 
  these 
  embankments 
  cannot 
  have 
  served 
  as 
  the 
  founda- 
  

   tions 
  for 
  homes 
  of 
  men. 
  He 
  remarks 
  that 
  none 
  of 
  the 
  known 
  

   burrowing 
  animals 
  execute 
  such 
  works, 
  whilst 
  hurricanes 
  could 
  

   not 
  have 
  accumulated 
  materials 
  with 
  such 
  regularity. 
  He 
  added 
  

   that 
  in 
  his 
  opinion 
  it 
  was 
  impossible 
  to 
  say 
  anything 
  definite 
  

   with 
  regard 
  to 
  their 
  origin, 
  which 
  seemed 
  to 
  be 
  inexplicable. 
  

   Other 
  archaeologists 
  are 
  more 
  positive 
  ; 
  they 
  consider 
  that 
  these 
  

  

  * 
  Report 
  to 
  Capt. 
  Talcott, 
  1839, 
  in 
  Humphrey's 
  and 
  Abbott's 
  Report, 
  

   Appendix 
  A. 
  

  

  t 
  First 
  Annual 
  Report 
  of 
  the 
  La. 
  State 
  Geol. 
  Survey 
  in 
  An. 
  Rept. 
  Board 
  

   of 
  Supervisors 
  of 
  the 
  La. 
  State 
  Seminary 
  for 
  Learning 
  and 
  Military 
  Acad- 
  

   emy 
  for 
  1869, 
  p. 
  82, 
  1870. 
  

  

  