BAIN 
ULKI 
CA£6]  COPPER    DEPOSITS    OF    MISSOURI.  235 
incidental  to  the  mining  of  the  latter  and  the  Raving  of  nickel  and 
cobalt.  An  effort  is  now  being  made  to  develop  certain  deposits 
which  show  distinct  bands  rich  in  copper.. 
In  Shannon  County  copper  occurs  at  a  number  of  points  and  efforts 
have  been  made  since  1837  to  develop  a  copper  industry.  The  best 
known  prospects  are  the  Slater,  Jerktail,  Sutton,  and  Casey.  At  the 
first  three  the  copper,  mainly  malachite,  but  subordinately  chalco- 
pyrite,  occurs  as  the  cement  of  a  basal  conglomerate  where  the  Gas- 
conade limestone  rests  upon  the  sloping  surface  of  Cambrian  por- 
phyry hills.  At  the  Casey  the  ore  occurs  as  an  impregnation  of  a 
horizontal  shale  bed  much  higher  in  the  formation,  if  not,  indeed,  in 
the  overlying  Roubidoux. 
In  all  these  occurrences  the  copper  is  believed  to  be  due  to  concen- 
tration from  the  surrounding  rocks,  and  the  locus  to  have  been  deter- 
mined mainly  by  geographic  conditions  obtaining  at  the  time  the 
limestone  was  formed.  The  deposits  are  bedded  and  may  easily  be 
prospected  by  drilling. 
Near  Sullivan  the  Missouri  Copper  Mountain  Mining  Company  is 
Avorking  a  body  of  copper  ore  consisting  of  residual  clay  in  which  are 
balls  and  nests  of  chalcopyrite  and  malachite.  A  twenty-day  run  in 
November  resulted  in  the  production  of  22,500  pounds  of  metallic 
copper.  The  ore  body  is  the  result  of  the  decomposition  of  the 
Roubidoux  and  the  beds  immediately  below.  This  is  the  horizon  at 
which  specular  hematite  commonly  occurs  throughout  the  region, 
and  in  the  bottom  of  many  of  the  old  iron  pits  a  certain  amount  of 
copper  is  found. 
Summary. — Copper  in  the  form  of  sulphides  and  carbonates  has 
been  found  at  many  points  in  southern  Missouri  and  has  been  mined 
in  several  localities,  notably  in  Ste.  Genevieve,  Madison,  Shannon, 
Jefferson,  and  Crawford  counties.  Very  large  deposits,  rivaling 
those  of  the  West,  have  not  been  found  and  are  not  to  be  expected. 
The  character  of  the  ore  and  the  low  cost  of  flux,  fuel,  and  labor  make 
it  possible  to  work  some,  at  least,  of  the  deposits  with  profit. 
The  deposits  show  a  preference  for  certain  stratigraphic  horizons, 
and,  being  bedded,  may  be  prospected  with  ease  and  economy.  The 
common  association  of  sulphides  with  specular  iron  in  this  region 
points  to  the  advisability  of  the  investigation  of  the  old  iron  pits  of 
the  sandstone  region.  While  any  copper  deposits  found  will  proba- 
bly not  be  large,  they  should  be  easily  and  cheaply  mined.  In  Shan- 
non County  the  most  favorable  localities  are  along  the  contact  of 
porphyry  and  dolomite  at  points  where  the  conglomerate  beds  at  the 
base  of  the  latter  fill  in  shallow  basins  in  the  crystalline  rocks.  In  the 
disseminated  lead  district  of  southeastern  Missouri  copper  occurs  in 
connection  with  the  lead,  and  at  a  few  points  can  be  saved  to 
advantage. 
