﻿214 
  GEOLOGY. 
  

  

  ail 
  excursion 
  to 
  one 
  of 
  the 
  large 
  ravines 
  in 
  Adams 
  

   County, 
  where 
  it 
  is 
  exposed 
  to 
  the 
  depth 
  at 
  least 
  of 
  fifty 
  

   feet. 
  Speaking 
  of 
  the 
  result 
  of 
  this 
  examination, 
  in 
  his 
  

   travels 
  subsequently 
  published, 
  he 
  remarks 
  that 
  "the 
  

   resemblance 
  between 
  this 
  loam 
  and 
  the 
  fluviatile 
  silt 
  of 
  

   the 
  valley 
  of 
  the 
  Rhine, 
  generally 
  called 
  Loess, 
  is 
  most 
  

   perfect." 
  

  

  Its 
  imbedded 
  fossils 
  are 
  chiefly 
  bleached 
  helices 
  or 
  

   snail 
  shells, 
  together 
  with 
  mammalian 
  remains, 
  hereafter 
  

   to 
  be 
  noticed 
  in 
  detail, 
  under 
  the 
  head 
  of 
  the 
  Palaeon- 
  

   tology 
  of 
  the 
  State. 
  

  

  At 
  every 
  bluff 
  on 
  the 
  Mississippi, 
  from 
  Fort 
  Adams 
  

   to 
  the 
  Yazoo, 
  and 
  in 
  the 
  hills 
  in 
  the 
  rear, 
  this 
  loam 
  is 
  

   seen, 
  and 
  the 
  roads 
  leading 
  into 
  the 
  interior 
  cut 
  into 
  it 
  

   deeply 
  and 
  expose 
  it 
  on 
  every 
  hand. 
  

  

  On 
  the 
  declivities 
  of 
  the 
  hills 
  bordering 
  the 
  Yazoo, 
  

   and 
  its 
  tributaries 
  on 
  the 
  east, 
  it 
  is 
  frequently 
  seen 
  and 
  

   has 
  been 
  observed 
  in 
  the 
  bluffs 
  at 
  Memphis, 
  but 
  much 
  

   diminished 
  in 
  thickness 
  of 
  the 
  deposit. 
  

  

  Its 
  highly 
  calcareous 
  properties, 
  its 
  abundance, 
  distri- 
  

   bution, 
  and 
  locality, 
  entitle 
  it 
  to 
  a 
  further 
  notice, 
  which 
  

   it 
  will 
  receive 
  among 
  our 
  other 
  Marls. 
  

  

  SANDSTONE— 
  DA 
  VION 
  ROCK. 
  

  

  Among 
  the 
  few 
  consolidated 
  rocks 
  which 
  our 
  Alluvio- 
  

   Tertiary 
  formations 
  afford, 
  susceptible 
  of 
  use 
  as 
  building 
  

   materials, 
  we 
  have 
  three 
  or 
  four 
  varieties 
  of 
  limestones, 
  

   and 
  sandstones 
  of 
  as 
  many 
  aspects. 
  

  

  The 
  Davion 
  Rock 
  of 
  Fort 
  Adams 
  is 
  an 
  argillo-silicious 
  

   composition, 
  of 
  a 
  dingy 
  white 
  color 
  in 
  the 
  mass, 
  contain- 
  

   ing 
  a 
  small 
  proportion 
  of 
  sand, 
  cemented 
  together 
  and 
  

   tinged 
  by 
  a 
  brownish-red 
  metallic 
  oxide, 
  which 
  pervades 
  

  

  