GLASS    SAND    OF    MIDDLE    MISSISSIPPI    BASIN.  471 
A  drill  is  said  to  have  shown  sandstone  to  a  depth  of  8  1'oet  below  the  base  of  the  exposure. 
This  would  indicate  a  total  thickness  of  over  20  feet.  In  natural  outcrops  the  rock  is  usually 
stained  dark  brown,  and  at  this  quarry  a  comparatively  fresh  exposure  showed  consider- 
able discoloration,  indicating  that  the  material  is  deeply  oxidized.  Analysis  No.  5  (p.  462) 
shows  this  sand  to  be  fairly  high  in  silica,  but  to  contain  too  much  iron  to  make  anything 
but  the  commonest  jar  and  bottle  glass,  and  the  same  may  be  said  of  sand  from  a  point  on 
the  ridge  west  of  Havana,  near  the  county  line  (No.  6,  p.  462).  These  sands  are  also 
slightly  finer  than  is  desirable,  but  this  may  be  offset  by  the  fact  that  the  grains  are  mostly 
sharp.  Two  samples  from  near  Niotaze  (Nos.  7  and  8,  p.  462)  proved  to  be  altogether 
too  fine  grained  and  rather  low  in  silica.  The  high  content  of  alumina  is  due  to  the  mica- 
ceous character  of  the  sandstone,  a  feature  common  to  the  sandstones  of  the  region.  It 
is  probable,  however,  that  sand  at  present  under  heavier  cover  would  prove  of  slightly 
better  composition  throughout  this  locality.  This  could  be  economically  determined  by 
shallow  drilling  along  the  sandstone  ridges  in  the  vicinity  of  Caney,  Havana,  and  Niotaze, 
and  in  view  of  the  importance  of  developing  low-grade  glass  sand  it  might  be  worth  while 
to  undertake  it.  One  drill  hole  in  each  locality,  if  put  down  in  solid  rock,  would  determine 
the  quality  of  the  sand  much  more  satisfactorily  than  openings  along  the  face  of  a  bluff. 
Southwest  of  Fredonia,  along  the  escarpment  on  the  south  side  of  Fall  River,  the  sand- 
stone is  locally  almost  white,  and  such  samples  (Nos.  1  and  2,  p.  462)  on  analysis  proved  to 
carry  the  least  iron.  This  rock  is  not  so  friable  as  the  St.  Peter  sandstone,  but  it  can  be 
mechanically  crushed  and  its  evenness  and  comparative  sharpness  of  grain  should  render 
it  satisfactory  as  a  low-grade  glass  material.  The  chief  considerations  in  regard  to  the 
practicability  of  opening  up  the  deposit  concern  the  outlay  for  equipment  and  trackage, 
since  the  best  material  lies  about  4  miles  from  a  railroad.  The  large  investments  in  glass 
factories  in  southeastern  Kansas  indicate  faith  in  a  long  life  for  the  industry.  With  per- 
manency assured  to  the  business,  even  if  the  cost  of  production  here  were  100  per  cent 
greater  than  in  districts  farther  east,  sand  might  be  sold  at  a  profit  and  still  save  money 
to  the  buyer.  Other  outcrops,  whet*1  some  prospecting  has  been  done,  were  found  to  show 
about  20  feet  of  sandstone  filled  with  more  or  less  ferruginous  spots.  The  best  sample,] 
that  could  be  obtained  here  have  been  examined  with  results  given  under  No.  4  (p.  462). 
From  a  bed  of  sandstone  apparently  near  the  base  of  the  Buxton  formation,  lh  miles 
southeast  of  Fredonia,  a  sample  was  taken,  and  its  properties  are  given  under  No.  3  (p.  462). 
Only  about  6  feet  of  a  cross-bedded  sandstone  show  here  above  the  level  of  a  small  creek. 
The  rock  is  a  light-gray  micaceous,  porous,  soft  sandstone,  with  grains  somewhat  angular 
and  a  trifle  coarser  than  is  usual  in  sandstones  of  this  vicinity.  The  rock  has  a  sprinkling 
of  specks  of  iron  rust  running  through  it.     The  total  thickness  could  not  be  ascertained. 
WISCONSIN. 
In  southwestern  Wisconsin  along  Mississippi  River  and  its  tributaries,  from  a  few  miles 
above  Dubuque,  Iowa,  nearly  to  Wisconsin  River,  the  St.  Peter  sandstone  is  a  persistent 
formation  lying  low  in  the  valleys  in  the  southwestern  part  of  the  area  and  rising  to  the 
tops  of  the  hills  toward  the  northeast.  Where  low  in  the  section  the  sandstone  is  heavily 
covered  by  limestone  and  dolomite  and  in  places  is  badly  iron-stained,  but  in  general  it  is 
protected  from  waters  descending  from  the  overlying  formations  by  a  bed  of  clay  shale. 
The  sandstone  is  usually  so  soft  as  to  be  worked  with  a  pick  and  shovel,  and  it  is  quarried 
extensively  for  local  uses,  although  it  is  by  no  means  as  sharp  a  sand  as  might  be  desired 
for  building  purposes.  It  would  probably  make  a  good  glass  sand,  but  in  localities  along 
Mississippi  River  near  the  Chicago,  Burlington  and  Quincy  Railroad,  or  near  the  Chicago, 
Milwaukee  and  St.  Paul  Railway  on  the  Iowa  side,  where,  situated  close  to  transportation 
facilities,  it  is  doubtful  if  it  could  be  exploited  except  by  mining.  The  distribution  of  the 
St.  Peter  sandstone  has  been  mapped  during  the  survey  of  the  Lancaster  and  Mineral  Point 
quadrangles,  and  the  maps  are  expected  soon  to  be  available  in  the  Lancaster-Mineral 
Point  folio.     Additional  topographic  maps  that  comprise  outlying  edges  of  this  district 
