﻿CLAYS 
  OF 
  NEW 
  YORK 
  621 
  

  

  Missouri^ 
  

  

  The 
  clays 
  of 
  Missouri 
  belong 
  to 
  tlie 
  following 
  classes 
  : 
  

  

  Chinaware 
  clays 
  

  

  Flint 
  clays 
  

  

  Plastic 
  fire 
  clays 
  

  

  Pottery 
  or 
  stoneware 
  clays 
  

  

  Shale, 
  and 
  brick 
  clays 
  

  

  China 
  war 
  6 
  clays. 
  The 
  llissonri 
  kaolins 
  south 
  of 
  the 
  Missouri 
  

   river 
  are 
  of 
  Paleozoic 
  age. 
  The 
  belt 
  is 
  worked 
  in 
  Cape 
  Girardeau 
  

   and 
  Bollinger 
  co. 
  and 
  extensively 
  in 
  Howell 
  co. 
  The 
  Misr 
  

   souri 
  kaolins 
  are 
  residual, 
  and 
  the 
  interesting 
  feature 
  about 
  them 
  

   is 
  that 
  they 
  have 
  been 
  derived 
  from 
  the 
  decay 
  of 
  aluminous 
  lime- 
  

   stone, 
  whereas 
  the 
  igneous 
  rocks 
  of 
  the 
  region 
  furnish 
  only 
  impure 
  

   chinaware 
  clay. 
  The 
  Missouri 
  kaolin 
  is 
  generally 
  highly 
  silicious 
  

   in 
  its 
  composition, 
  but 
  this 
  is 
  not 
  exceptional. 
  

  

  Flint 
  clays. 
  The 
  flint 
  clays 
  of 
  Missouri 
  often 
  approach 
  closely 
  in 
  

   composition 
  to 
  kaolinite. 
  They 
  occur 
  in 
  the 
  central 
  part 
  of 
  the 
  

   stat€, 
  being 
  abundant 
  in 
  the 
  counties 
  of 
  Warren, 
  Montgomery, 
  

   Calloway, 
  Osage, 
  Pranklin, 
  Crawford 
  and 
  Phelps. 
  The 
  geologic 
  

   age 
  may 
  be 
  Carboniferous, 
  Silurian 
  or 
  Ordovician. 
  They 
  form 
  a 
  

   cradle-like 
  deposit 
  in 
  the 
  limestone 
  which 
  has 
  a 
  depth 
  of 
  50 
  to 
  200 
  

   feet, 
  and 
  15 
  to 
  50 
  feet. 
  Most 
  of 
  them 
  have 
  less 
  than 
  2^ 
  of 
  im- 
  

   purities. 
  They 
  have 
  from 
  30^ 
  to 
  43^ 
  of 
  alumina, 
  and 
  14^ 
  to 
  15^ 
  of 
  

   combined 
  water, 
  thus 
  resembling 
  kaolinite 
  in 
  their 
  composition. 
  

   They 
  are 
  devoid 
  of 
  plasticity, 
  and 
  in 
  use 
  have 
  to 
  be 
  mixed 
  with 
  

   plastic 
  clays. 
  They 
  generally 
  begin 
  to 
  fuse 
  at 
  a 
  temperature 
  of 
  

   2300°, 
  but 
  do 
  not 
  become 
  viscous 
  under 
  2700°, 
  and 
  are 
  therefore 
  

   fairly 
  refractory. 
  , 
  

  

  Plastic 
  fire 
  clays. 
  All 
  of 
  these 
  occur 
  in 
  the 
  Carboniferous, 
  asso- 
  

   ciated 
  with 
  seams 
  of 
  coal. 
  They 
  are 
  generally 
  massive, 
  dense, 
  hard, 
  

   and 
  plastic. 
  Those 
  around 
  St 
  Louis 
  are 
  specially 
  important 
  and 
  

   form 
  the 
  base 
  of 
  the 
  enormous 
  local 
  development 
  of 
  the 
  clay-work- 
  

   ing 
  industry. 
  

  

  iMo. 
  geol. 
  surv., 
  11. 
  H. 
  A. 
  Wheeler. 
  Clays 
  of 
  Missouri. 
  

  

  