﻿I] 
  Generai. 
  Geology 
  : 
  Quaternary 
  117 
  

  

  calcareous 
  yellow 
  loam 
  or 
  brick 
  clay 
  often 
  overlying 
  the 
  typical 
  

   loess 
  and 
  extending 
  over 
  a 
  much 
  larger 
  territory. 
  For 
  this 
  

   formation 
  he 
  proposed 
  the 
  name 
  Yellow 
  Loam.* 
  He 
  considered 
  

   it 
  genetically 
  distinct 
  from 
  the 
  loess. 
  " 
  More 
  recent 
  investiga- 
  

   tions 
  have 
  shown 
  that 
  it 
  not 
  only 
  overlies 
  the 
  loess 
  but 
  some- 
  

   times 
  underlies 
  and 
  grades 
  laterally 
  into 
  the 
  loess. 
  They 
  are 
  

   now 
  regarded 
  as 
  one 
  and 
  the 
  same 
  formation, 
  the 
  loess 
  represent- 
  

   ing 
  a 
  local 
  development 
  of 
  the 
  loam. 
  

  

  Distrihdion 
  of 
  the 
  Yellow 
  loam. 
  — 
  On 
  the 
  geological 
  map 
  of 
  the 
  

   State 
  the 
  thick 
  deposits 
  of 
  loess-like 
  yellow 
  loam 
  on 
  the 
  Bayou 
  

   Macon 
  hills, 
  on 
  the 
  Avoyelles 
  prairie 
  and 
  on 
  the 
  uplands 
  along 
  

   the 
  Teche 
  have 
  all 
  been 
  represented 
  as 
  belonging 
  to 
  this 
  

   deposit. 
  A 
  thin 
  layer 
  of 
  the 
  yellow 
  loam 
  covers 
  a 
  much 
  

   larger 
  area. 
  It 
  extends 
  over 
  nearly 
  the 
  whole 
  of 
  the 
  western 
  

   Port 
  Hudson, 
  becoming 
  in 
  that 
  region 
  the 
  chocolate 
  colored 
  loam 
  

   of 
  Clendenin. 
  On 
  the 
  eastern 
  side 
  of 
  the 
  river 
  it 
  is 
  found 
  occa- 
  

   sionally 
  overlying 
  the 
  Grand 
  Gulf 
  and 
  lyafayette, 
  and 
  in 
  places 
  

   over 
  the 
  Port 
  Hudson. 
  The 
  mantle-like 
  layer 
  of 
  yellow 
  calca- 
  

   reous 
  clay 
  observed 
  on 
  the 
  Five 
  Islands 
  seems 
  to 
  be 
  a 
  develop- 
  

   ment 
  of 
  the 
  yellow 
  loam. 
  

  

  The 
  Ali^uvium 
  and 
  Recent 
  Coastal 
  Formations 
  

  

  Recent 
  coastal 
  formations 
  . 
  — 
  Some 
  of 
  the 
  diflficulties 
  experienced 
  

   in 
  differentiating 
  these 
  deposits 
  and 
  the 
  Port 
  Hudson 
  proper 
  

   have 
  been 
  discussed 
  under 
  the 
  Port 
  Hudson. 
  The 
  Quaternary 
  

   coastal 
  formations 
  seem 
  to 
  be 
  in 
  all 
  respects 
  continuous, 
  and 
  it 
  

   seems 
  quite 
  impossible 
  to 
  use 
  the 
  term 
  Port 
  Hudson 
  in 
  the 
  

   coastal 
  region 
  without 
  including 
  in 
  it 
  some 
  of 
  the 
  most 
  recent 
  

   formations. 
  The 
  blue 
  clay 
  stratum 
  with 
  stumps, 
  which 
  Hilgard 
  

   reports 
  around 
  Petite 
  Anse, 
  and 
  which 
  he 
  refers 
  to 
  the 
  Port 
  

   Hudson 
  seems 
  to 
  belong 
  to 
  the 
  subsidence 
  now 
  in 
  progress. 
  This 
  

   conclusion 
  is 
  arrived 
  at 
  by 
  the 
  fact 
  that 
  in 
  the 
  immediate 
  neigh- 
  

   borhood 
  of 
  the 
  stumps, 
  and 
  skirting 
  the 
  edge 
  of 
  the 
  present 
  

   sea-marsh 
  is 
  a 
  cypress 
  swamp. 
  Thomassy 
  describes 
  on 
  the 
  sea- 
  

   ward 
  margin 
  of 
  the 
  swamp 
  a 
  number 
  of 
  dead 
  trees 
  which 
  clearly 
  

  

  * 
  Mississippi 
  Rept., 
  i860, 
  p. 
  197. 
  

  

  