TAFF 
SII 
4lerD]  MUSCOGEE    OIL   FIELD,    INDIAN    TERRITORY.  443 
Gas. — At  a  depth  of  800  to  840  feet  is  a  sand  which  yields,  locally, 
salt  water  and  gas.     It  is  referred  to  by  the  driller  as  "  salt  sand." 
Several  of  the  wells  have  yielded  considerable  quantities  of  gas  from 
this  horizon.     As  in  most  cases  the  yield  was  not  large,  drilling  was 
continued  down  to  the  oil  sand.     In  one  well — the  "  Great  Chief  " — 
located  near  the  center  of  the  west  side  of  the  oil-producing  area,  a  gas 
flow  was  encountered  at  a  depth  of  825  feet,  the  capacity  of  which  was 
estimated  to  be  1,000,000  cubic  feet  per  day.     This  gas  was  utilized  for 
fuel  in  the  ice  and  electric-light  plants  for  some  time,  but  later  drilling 
was  continued  to  the  oil  sand  and  a  profitable  flow  of  oil  secured. 
Another  well,  "  The  United,"  at  the  north  end  of  the  area,  yielded  an 
estimated  flow  of  more  than  1,000,000  cubic  feet  of  gas,  but  the  well 
became  flooded  by  a  strong  flow  of  salt  water  and  had  to  be  abandoned. 
Rock  section. — The  wells  at  Muscogee  were  put  down  by  several 
drilling    companies.     The    oil-bearing    sand     was    encountered     at 
approximately  the  same  depth,  but  there  are  considerable  differences 
between  the  reported  sections  as  to  the  succession  of  shale,  sandstone, 
md  limestone.     The  Survey  has  not  been  able  to  obtain  drillings  from 
the  Muscogee  wells.     If  these  had  been  secured,  it  is  believed  a  more 
satisfactory  record  could  be  constructed.     A  well  recently  drilled  to 
a  depth  of  1,176  feet  at  Fort  Gibson  furnished  05  samples,  from  which 
a  fairly  accurate  section  of  the  rocks  can  be  constructed.     The  mate- 
rial from  this  well  has  shown  that  the  cherty  Boone  formation  of  the 
Mississippian  series  exposed  at  the  surface  in  eastern  Cherokee  Nation 
s  simply  a  dark-colored  siliceous  limestone  where  it  reaches  depths 
:>elow  the  level  of  weathering.     The  cherty  Boone  limestone  forms 
,  large  part  of  the  Mississippian  in  eastern  Cherokee  Nation,  and  is 
he  only  part  known  to  the  well  driller.     The  change  in  character 
)f  the  Mississippian  cherty  limestone  where  it  passes  below  depths 
)f  a  few  hundred  feet  has  caused  the  well  driller  to  fail  to  interpret 
his  formation  correctly.     This  chertjr  limestone  was  believed  to  be 
he  datum  below  which  oil  does  not  occur  in  the  Indian  Territory - 
vansas  field. 
The   logs   of   the   Muscogee   wells,   however,   accord   generally   in 
lowing  that  shales  and  sandstones  with  little  lime  make  the  rock 
ection  from  the  surface  to  a  depth  of  about  TOO  feet.     At  this  depth 
hick  limestones  are  generally  encountered  and  greater  resistance  to 
le  drill  is  reported.     Limestone,  shale,  and  sandstone  in  alternating 
uccession  continue,  according  to  report,  to  the  oil-bearing  sand,  which 
entered  at  depths  of  1,020  to  1,060  feet.     On  comparing  this  gen- 
ral   record   with   detailed   sections   made   between   Tahlequah   and 
[eosho  or  Grand  River  and  with  the  section  of  the  Fort  Gibson  well, 
:  is  found  that  the  top  of  the  limestones  is  100  to  200  feet  above  the 
op  of  the  Mississippian.     In  this  region  the  thickness  of  the  Missis- 
