taff.]  COAL   WORK    IN   INDIAN   TERRITORY.  393 
in  approximately  the  stratigraphic  position  of  the  Witteville  coal 
and  is  being  mined  on  Elk  Creek  in  Creek  Nation,  5J  miles  east  of 
Checotah.  The  bed  here  is  2  feet  6  inches  thick  and  the  coal  is  of 
good  quality.  No  information  has  been  obtained  concerning  the 
occurrence  of  this  coal  farther  north. 
CHEROKEE-CREEK    COAL    FIELDS. 
LOCATION. 
The  northern  part  of  the  Indian  Territory  coal  field,  included 
in  the  area  mapped  as  PI.  II,  has  not  been  surveyed  in  detail,  except 
an  area  of  nearly  1,000  square  miles  in  the  southeastern  portion, 
within  the  Muscogee  quadrangle.  The  Muscogee  quadrangle  is  in- 
cluded between  parallels  of  latitude  35°  and  35°  30'  and  merid- 
ians of  longitude  94°  30'  and  95°.  In  other  parts  of  the  field  in- 
vestigations of  coals  have  been  made  and  certain  sandstone  and 
limestone  formations  traced  as  an  aid  to  the  interpretation  of  the 
rock  structure  and  the  location  of  the  coal  beds  with  wThich  they 
are  related.  The  outcrops  of  the  limestone  beds  and  coal  prospects 
in  northern  Cherokee  Nation  were  traced  and  mapped  by  George  I. 
Adams,  of  the  United  States  Geological  Survey,  and  John  Bennett. 
The  locations  of  limestone,  sandstone,  and  coal  beds  in  the  Creek 
Nation  were  made  by  M.  K.  Shaler  in  the  progress  of  coal-land 
surveys  for  the  Commission  to  the  Five  Civilized  Tribes.  The  con- 
tinuous lines  on  the  map  show  the  locations  of  outcrops  of  limestones 
and  coal,  and  the  dotted  lines  indicate  only  approximately  accurate 
locations  made  by  reconnaissance  surveys. 
As  stated  in  the  description  of  the  rocks  of  the  Choctaw  coal  field, 
the  coal  beds  and  formations  in  which  they  occur  south  of  Canadian 
River  can  not  be  traced  north  of  the  vicinity  of  Muscogee.  The 
detailed  surveys,  therefore,  of  the  Mus'cogee  quadrangle  have  little 
economic  bearing  on  the  coal  in  northern  Indian  Territory,  and  the 
general  geology  will  not  be  discussed  separately  from  the  remainder 
of  the  Cherokee-Creek  field. 
STRATIGRAPHY. 
The  rocks  of  the  Indian  Territory  coal  field,  especially  the  lower 
part  of  the  section,  decrease  in  thickness  northward,  and  with  this 
decrease  goes  a  change  in  the  character  of  the  sediments.  On  ap- 
proaching Arkansas  River  in  northern  Creek  Nation  thv  thick  sec- 
tion of  coal-bearing  rocks  of  southern  Indian  Territory  is  found 
to  be  greatly  reduced  in  thickness,  and  the  numerous  sandstone 
beds  are  too  thin  or  shaly  to  be  recognized.  With  the  dying  out 
of  the  sandstone  deposits  there  is  an  increase  in  lime  in  the  rocks, 
indicated  by  the  presence  of  thin  limestone  beds  found  interstratified 
