468  CONTRIBUTIONS    TO   ECONOMIC    GEOLOGY,  1906,  PART   I. 
the  work.  A  much  larger  plant  is  now  nearing  completion  at  Little 
Rock,  to  which  the  crude  products  of  the  mine  will  be  shipped  in  the 
future,  to  be  manufactured  into  various  phosphatic  and  fertilizer 
products. 
Little  Rock  was  selected  for  the  new  plant  because  of  its  central 
location  and  its  good  railroad  facilities.  The  company  in  the  mean- 
time has  had  its  name  legally  changed  to  the  Arkansas  Fertilizer 
Compan}r.  The  new  plant  will  have  an  annual  capacity  of  40,000 
tons,  with  a  shipping  capacity  of  15  to  18  cars  a  day. 
The  company  has  mined  to  this  time  (October,  1906)  about  10,000 
tons  of  crude  phosphate,  of  which  about  2,250  tons  have  been  pro- 
duced within  the  last  four  months.  The  present  output  of  the  mine 
is  approximately  from  500  to  600  tons  a  month.  The  company  is 
now  manufacturing  fine  ground  crude  phosphate,  acid  phosphate, 
and  a  full  line  of  other  fertilizers  made  from  Arkansas  phosphates 
blended  with  ammoniates,  potash,  etc. 
Description  of  developed  deposits. — The  deposits  first  developed  are 
in  a  small  ravine  that  enters  East  Lafferty  Creek  from  the  east,  in 
the  northern  part  of  sec.  14,  T.  14  N.,  R.  8  W.  At  this  place  the 
phosphate  rocks  outcrop  on  the  hillsides  at  an  elevation  of  about  500 
feet  above  sea  level,  and  have  a  low  dip  toward  the  west.  The 
development  extends  for  about  half  a  mile  on  either  side  of  the  road 
that  runs  along  the  bottom  of  the  ravine.  The  work  at  this  point 
was  done  mainly  by  running  adits  into  the  hillside  and  mining  out 
the  rock,  though  some  of  the  rock  was  obtained  from  open  quarries. 
The  phosphate  at  this  place  occurs  beneath  a  ledge  of  St.  Clair 
limestone  from  8  t;»  in  feel  thick.  The  workings  had  been  abandoned 
for  three  years  when  the  writer  last  visited  the  place,  and  the  expos- 
ures were  more  or  less  obscured.  The  bed  that  was  worked  here  is 
about  22  inches  thick,  lying  beneath  a  yellow  to  brown  colored  clay 
from  4  to  5  feet  thick.  Beneath  the  phosphate  bed  is  a  phosphatic 
sandstone,  the  thickness  of  which  was  not  determined,  but  it  rests 
upon  the  Polk  Bayou  limestone.  The  two  phosphate  beds  are  usu- 
ally separated  by  a  layer  of  manganiferous  iron  ore  1  or  2  inches 
thick. 
Such  exposures  of  the  developed  phosphate  bed  as  were  seen  here 
showed  that  it  had  been  considerably  weathered  and  its  original 
appearance  much  changed.  The  rock  observed  in  the  adits  was  soft 
and  earthy  and  of  a  dark  brown  color,  containing  numerous  small 
subangular  fragments  and  closely  specked  by  small,  white  grains. 
On  examination  under  the  magnifier  the  rock  is  found  to  contain 
large  numbers  of  small,  apparently  sandy  pebbles.  Where  exposed 
to  the  weather  it  is  brown  to  yellow  on  fresh  surfaces.  Many  of  the 
old  surfaces  and  joints  are  colored  black  with  a  thin  coat  of  manganese 
stain.     Weathering  brings  out  thin  shaly  laminae  in  some  places. 
