182  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1905. 
Approximately  25,000  tons  of  ore  wore  produced  during  the  year  1905.     The  mine  section 
as  exposed  at  one  point  shows  the  following  beds: 
Section  at  mine  of  Rose  Run  Iron  Company  near  Owingsville,  Ky. 
Feet. 
Yellow  surface  clay 2 
Thin-bedded  sandstone  and  shale 5 
Blue  clay  shale 6 
Iron  ore 4 
The  ore  varies  in  thickness  from  1^  to  5  feet,  2  feet  being  perhaps  an  average.  About  5 
inches  of  green  ore  generally  overlie  the  red  ore.  This  5-inch  band  carries  a  percentage  of 
sulphur,  which  necessitates  roasting  before  it  can  be  used.  It  was  formerly  roasted  at  the 
mines,  but  at  present  it  is  thrown  out.  The  high  percentage  of  lime  in  the  ore  makes  it 
unnecessary  to  add  lime  for  fluxing.  A  scries  of  5  analyses,  made  by  different  parties,  show^ 
the  lime  content  to  run  from  8.86  to  11.91  per  cent,  and  the  silica  from  4.19  to  8.73  per  cent. 
The  same  analyses  show  the  iron  to  run  from  35.7  to  38.6  per  cent;  magnesia,  4.08  to  5.84 
per  cent ;  alumina,  3.54  to  6.80  per  cent,  and  phosphorus,  0.43  to  0.61  per  cent. 
About  15  acres  of  the  ore  have  been  worked  out.  The  yield  of  ore  per  acre  is  estimated 
at  about  3,000  tons  per  foot  of  thickness.  The  Clinton  ore  which  has  been  mined  may 
therefore  be  estimated  at  approximately  125,000  tons.  There  are  probably  several  thousand 
acres  of  the  Clinton  ore  of  about  the  same  grade  and  thickness  as  that  which  has  been 
mined.     Only  a  --mall  percentage  of  this  can  be  mined  by  stripping,  however. 
With  the  rapid  exhaustion  of  the  supply  of  high-grade  ores  and  the  consequent  increase 
in  the  demand  for  ore  of  this  grade  which  may  be  expected  in  the  future,  much  of  theClintol 
ore  which  can  not  now  be  profitably  mined  may  eventually  be  utilized. 
