﻿Ill] 
  Shreveport 
  Area 
  : 
  Lakes 
  187 
  

  

  the 
  results 
  of 
  these 
  borings 
  Capt. 
  Willard 
  says 
  : 
  " 
  The 
  borings 
  

   also 
  disprove 
  the 
  notion 
  that 
  these 
  lakes 
  were 
  formed 
  by 
  the 
  

   same 
  convulsion 
  that 
  made 
  those 
  at 
  New 
  Madrid, 
  the 
  strata 
  

   plainly 
  being 
  water 
  deposits 
  without 
  contortions 
  that 
  the 
  

   upheaval 
  or 
  sinking 
  would 
  produce, 
  and 
  the 
  oak 
  stumps 
  as 
  well 
  as 
  

   the 
  cypress 
  are 
  everywhere 
  found 
  vertical. 
  "* 
  The 
  second 
  reason 
  

   is 
  that 
  a 
  theory 
  of 
  origin 
  similar 
  to 
  the 
  New 
  Madrid 
  lakes 
  will 
  

   hardly 
  account 
  for 
  the 
  peculiar 
  positions 
  of 
  these 
  lakes. 
  Lakes 
  

   of 
  the 
  type 
  of 
  Sodo 
  lake 
  and 
  lake 
  Cannisnia 
  might 
  be 
  produced 
  

   by 
  the 
  sinking 
  of 
  an 
  area 
  of 
  land 
  in 
  the 
  bottoms 
  by 
  earthquake 
  

   action, 
  but 
  it 
  must 
  be 
  confessed 
  that 
  it 
  would 
  be 
  a 
  most 
  peculiar 
  

   earthquake 
  or 
  series 
  of 
  earthquakes 
  which 
  would 
  drop 
  the 
  bot- 
  

   tom 
  out 
  of 
  every 
  large 
  valley 
  entering 
  Red 
  river 
  valley, 
  or 
  which 
  

   would 
  raise 
  the 
  land 
  at 
  just 
  the 
  points 
  where 
  these 
  valleys 
  enter 
  

   the 
  river 
  valley. 
  This 
  drives 
  us 
  to 
  the 
  supposition 
  that 
  the 
  sub- 
  

   sidence 
  was 
  not 
  local 
  but 
  extended 
  over 
  the 
  whole 
  valley 
  ; 
  

   effecting 
  the 
  hills 
  and 
  bottoms 
  alike 
  . 
  Such 
  a 
  movement 
  is 
  different 
  

   from 
  the 
  local 
  subsidences 
  in 
  the 
  bottoms 
  produced 
  by 
  the 
  earth- 
  

   quake 
  at 
  New 
  Madrid. 
  A 
  general 
  movement 
  of 
  this 
  kind 
  over 
  a 
  

   large 
  area 
  is 
  more 
  likely 
  to 
  be 
  produced 
  by 
  slow 
  crustal 
  move- 
  

   ments 
  than 
  by 
  an 
  earthquake. 
  

  

  A 
  general 
  subsidence 
  of 
  this 
  kind 
  is 
  capable 
  of 
  producing 
  sucli 
  

   lakes. 
  As 
  the 
  subsidences 
  progresses, 
  the 
  river 
  will 
  commence 
  

   building 
  up 
  its 
  channel 
  and 
  banks 
  in 
  an 
  effort 
  to 
  regain 
  its 
  base- 
  

   level. 
  If 
  this 
  movement 
  is 
  rapid, 
  Red 
  river 
  with 
  it 
  great 
  amount 
  

   of 
  sediment 
  will 
  build 
  up 
  its 
  bed 
  much 
  faster 
  than 
  the 
  less 
  muddy 
  

   tributaries. 
  This 
  will 
  result 
  in 
  the 
  elevation 
  of 
  the 
  river 
  above 
  

   the 
  tributary 
  streams 
  and 
  the 
  consequent 
  ponding 
  of 
  the 
  water 
  

   in 
  their 
  valleys. 
  

  

  The 
  fact 
  that 
  there 
  is 
  abundant 
  evidence 
  that 
  the 
  southern 
  

   part 
  of 
  the 
  United 
  States 
  is 
  sinking 
  f 
  seems 
  to 
  corroborate 
  this 
  

   theor}', 
  but 
  other 
  facts, 
  at 
  hand, 
  do 
  not 
  sustain 
  it. 
  If 
  such 
  a 
  

  

  * 
  An. 
  Rep. 
  Chief 
  of 
  Eng. 
  for 
  1893, 
  p. 
  2069, 
  1893. 
  

  

  t 
  This 
  evidence 
  consists 
  in 
  the 
  estuary 
  character 
  of 
  the 
  mouths 
  of 
  the 
  

   majority 
  of 
  Gulf 
  rivers 
  ; 
  the 
  great 
  depths 
  of 
  some 
  of 
  the 
  costal 
  rivers 
  ; 
  the 
  

   observations 
  of 
  Maj. 
  J. 
  B. 
  Ouinn 
  of 
  the 
  U. 
  S. 
  Engineers, 
  and 
  the 
  buried 
  

   shell 
  heaps 
  on 
  the 
  coast. 
  See 
  Five 
  Island 
  article 
  and 
  Geol. 
  Surv. 
  of 
  Ala., 
  

   1894, 
  pp. 
  45-47. 
  ■ 
  

  

  