﻿La 
  SALLE 
  COUNTY. 
  

  

  51 
  

  

  The 
  surface 
  deposits 
  of 
  LaSalle 
  county 
  will 
  furnish 
  an 
  inexhaust- 
  

   ible 
  supply 
  of 
  sand, 
  clay 
  and 
  gravel. 
  The 
  sand 
  pit 
  in 
  the 
  vicinity 
  

   of 
  Streator 
  furnishes 
  a 
  clean, 
  sharp 
  sand, 
  that 
  is 
  shipped 
  in 
  large 
  

   quantities 
  by 
  railroad 
  wherever 
  a 
  market 
  can 
  be 
  found. 
  The 
  fol- 
  

   lowing 
  section 
  may 
  be 
  seen 
  at 
  this 
  pit 
  : 
  

  

  Ft. 
  

   Brown 
  clay 
  4 
  

  

  Ash-colored 
  clay 
  4 
  

  

  Sand, 
  with 
  streaks 
  of 
  fine 
  gravel 
  , 
  20 
  

  

  Coarse 
  gravel 
  7 
  

  

  The 
  clay 
  used 
  in 
  making 
  tile 
  at 
  Streator 
  comes 
  from 
  the 
  bottom 
  

   of 
  what 
  were 
  formerly 
  shallow 
  surface 
  ponds, 
  that 
  have 
  been 
  filled 
  

   up 
  mainly 
  by 
  the 
  wash 
  from 
  the 
  higher 
  grounds 
  by 
  which 
  they 
  were 
  

   surrounded. 
  It 
  is 
  a 
  tough, 
  fine, 
  unctious 
  clay, 
  and 
  at 
  some 
  points 
  

   is 
  found 
  as 
  much 
  as 
  ten 
  or 
  twelve 
  feet 
  in 
  thickness. 
  It 
  is 
  evidently 
  

   more 
  modern 
  than 
  the 
  brown 
  clay 
  of 
  the 
  Drift 
  period, 
  and 
  overlays 
  

   that 
  deposit 
  when 
  both 
  are 
  present. 
  The 
  growth 
  and 
  decay 
  of 
  

   aquatic 
  grasses, 
  that 
  usually 
  abound 
  in 
  shallow 
  ponds, 
  produce 
  a 
  

   fine 
  silicious 
  sediment, 
  and 
  this, 
  with 
  the 
  wash 
  from 
  the 
  higher 
  

   grounds 
  adjacent 
  to 
  them, 
  will 
  fairly 
  account 
  for 
  the 
  occurrence 
  of 
  

   these 
  tough 
  clays 
  in 
  this 
  position. 
  In 
  other 
  portions 
  of 
  the 
  county 
  

   the 
  brown 
  clay 
  of 
  the 
  Drift, 
  or, 
  more 
  properly 
  speaking, 
  of 
  the 
  

   loess, 
  is 
  used 
  in 
  the 
  tile 
  factories 
  with 
  satisfactory 
  results. 
  

  

  In 
  closing 
  these 
  brief 
  notes 
  on 
  the 
  geology 
  of 
  LaSalle 
  county, 
  I 
  

   desire 
  to 
  express 
  my 
  obligations 
  to 
  Dr. 
  E. 
  Evans, 
  of 
  Streator, 
  for 
  

   valuable 
  information 
  in 
  regard 
  to 
  the 
  geology 
  of 
  that 
  part 
  of 
  the 
  

   county, 
  and 
  for 
  hospitable 
  entertainment, 
  and 
  transportation 
  to 
  such 
  

   localities 
  on 
  the 
  Vermilion 
  river 
  as 
  it 
  seemed 
  desirable 
  to 
  visit 
  ; 
  and 
  

   also 
  to 
  the 
  Hon. 
  Elmer 
  Brldwin 
  for 
  similar 
  favors 
  wbile 
  exploring 
  

   the 
  outcrop 
  on 
  the 
  river 
  in 
  the 
  vicinity 
  of 
  Farm 
  Ridge 
  ; 
  and 
  also 
  to 
  

   Mr. 
  John 
  B. 
  Duncan, 
  of 
  the 
  Caledonia 
  shaft, 
  Mr. 
  Cbas. 
  J. 
  Devlin, 
  

   of 
  the 
  Union, 
  and 
  the 
  proprietors 
  of 
  the 
  Oglesby 
  shaft, 
  for 
  a 
  de- 
  

   tailed 
  record 
  of 
  their 
  works. 
  

  

  It 
  is 
  to 
  be 
  regretted 
  that 
  a 
  detailed 
  record 
  of 
  every 
  coal 
  shaft 
  is 
  

   not 
  kept, 
  for 
  such 
  records 
  would 
  be 
  of 
  great 
  value, 
  not 
  only 
  to 
  the 
  

   proprietors 
  and 
  managers 
  of 
  the 
  mines, 
  but 
  to 
  all 
  who 
  desire 
  to 
  

   obtain 
  reliable 
  information 
  in 
  regard 
  to 
  the 
  value 
  and 
  extent 
  of 
  our 
  

   coal 
  resources. 
  

  

  