﻿I] 
  General 
  Geology: 
  Quaternary 
  113 
  

  

  same 
  time 
  the 
  term 
  Biloxi 
  sand 
  was 
  suggested 
  for 
  the 
  recent 
  

   costal 
  formations, 
  in 
  general 
  equivalent 
  to 
  the 
  recent 
  alluvium 
  

   of 
  the 
  river. 
  It 
  was 
  found 
  impossible 
  to 
  differentiate 
  

   them 
  in 
  the 
  field 
  and 
  in 
  1894 
  the 
  Pontchartrain 
  claj^s 
  and 
  Biloxi 
  

   sands 
  were 
  all 
  included 
  under 
  one 
  head, 
  the 
  Biloxi 
  sands.* 
  

  

  The 
  difficulty, 
  nay 
  impossibility, 
  of 
  distinguishing 
  between 
  

   the 
  different 
  parts 
  of 
  the 
  Quaternary 
  in 
  the 
  coastal 
  region 
  has 
  

   given 
  rise 
  to 
  a 
  very 
  interesting 
  discussion 
  on 
  the 
  thickness 
  of 
  

   the 
  recent 
  alluvium 
  in 
  the 
  delta 
  below 
  New 
  Orleans. 
  This 
  

   seems 
  to 
  be 
  one 
  of 
  those 
  points 
  where 
  a 
  person 
  can 
  take 
  either 
  

   side 
  and 
  prove 
  that 
  he 
  is 
  right. 
  If 
  the 
  period 
  of 
  the 
  recent 
  

   alluvium 
  be 
  said 
  to 
  begin 
  at 
  the 
  time 
  when 
  the 
  cutting 
  out 
  of 
  

   the 
  Port 
  Hudson 
  and 
  loess 
  deposited 
  in 
  the 
  valley 
  commenced, 
  

   then 
  the 
  delta 
  formed 
  of 
  this 
  material 
  would 
  be 
  composed 
  of 
  

   redeposited 
  Port 
  Hudson 
  material 
  with 
  marine 
  shells 
  and 
  exactly 
  

   the 
  same 
  difficulties 
  will 
  be 
  experienced 
  in 
  differentiating 
  the 
  two 
  

   deposits 
  that 
  are 
  experienced 
  both 
  east 
  and 
  west 
  of 
  the 
  delta 
  

   region. 
  If 
  the 
  period 
  of 
  the 
  recent 
  alluvium 
  be 
  defined 
  as 
  com- 
  

   mencing 
  when 
  the 
  period 
  of 
  degredation. 
  ceased, 
  the 
  same 
  

   difficulties 
  will 
  be 
  experienced. 
  Off 
  the 
  delta 
  today 
  marine 
  

   beds 
  are 
  forming 
  which 
  are 
  the 
  time 
  equivalents 
  of 
  the 
  recent 
  

   alluvium, 
  but 
  which 
  are 
  in 
  everyway 
  similar 
  to 
  those 
  which 
  

   formed 
  under 
  similar 
  conditions 
  in 
  the 
  Port 
  Hudson 
  period 
  

   proper. 
  Indeed 
  criteria 
  for 
  the 
  separation 
  of 
  the 
  Port 
  Hudson 
  

   proper 
  from 
  the 
  more 
  recent 
  deposits 
  in 
  the 
  lower 
  delta 
  region 
  

   seem 
  to 
  be 
  entirely 
  lacking. 
  All 
  our 
  present 
  knowledge 
  seems 
  to 
  

   justify, 
  is 
  to 
  lump 
  the 
  whole 
  together 
  as 
  has 
  been 
  done 
  east 
  of 
  

   of 
  the 
  Mississippi 
  in 
  the 
  Biloxi 
  sands 
  and 
  west 
  of 
  the 
  Mississippi 
  

   in 
  the 
  Port 
  Hudson. 
  

  

  Areal 
  distribution 
  and 
  topographical 
  featiires. 
  — 
  These 
  vast 
  beds 
  

   of 
  clay, 
  which 
  have 
  not 
  been 
  exposed 
  long 
  enough 
  for 
  the 
  

   development 
  of 
  drainage 
  systems 
  and 
  which 
  from 
  their 
  clayey 
  

   nature 
  prevent 
  a 
  perfect 
  subterranean 
  drainage, 
  have 
  had 
  a 
  very 
  

   marked 
  effect 
  on 
  the 
  topography 
  of 
  part 
  of 
  Louisiana. 
  East 
  of 
  

   the 
  Mississippi 
  they 
  have 
  given 
  rise 
  to 
  the 
  " 
  Pine 
  flats" 
  or 
  

   "Pine 
  meadows" 
  lying 
  between 
  the 
  pine 
  hills 
  and 
  the 
  coastal 
  

   marshes. 
  West 
  of 
  the 
  Mississippi 
  they 
  have 
  produced 
  another 
  

  

  *Geol. 
  Surv. 
  Ala., 
  1894, 
  p. 
  41, 
  

   H 
  

  

  