stone.]  OIL    AND    GAS    FIELDS    OF    GREENE    COUNTY,   PA.  401 
from  250  to  300  feet  thick.  This  average  depth  is  very  close  to  the 
actual  depths  of  the  Big  Injun  sandstone  as  found  in  Franklin  Town- 
ship. The  interval  varies,  however,  from  1,275  feet  in  Dunkard  and 
Perry  townships  to  1,182  feet  in  Morris  Township.  In  other  words, 
the  interval  is  nearly  100  feet  greater  in  the  southeastern  part  of 
Greene  County  than  it  is  in  the  vicinity  of  the  Fonner  oil  field. 
The  Big  Injun  sand  produces  oil  in  the  Mount  Morris  field,  Dunkard 
Township,  and  it  is  commonly  expected  to  contain  more  or  less  gas 
wherever  it  is  drilled  through.  This  sand  was  named  the  "  Big  Injun" 
by  some  driller  in  Washington  County,  Pa.,  on  account  of  its  thickness 
and  hardness. 
Below  the  Big  Injun  sand  the  drill  passes  through  a  series  of  inter- 
bedded  shales  and  sandstones  about  1,000  feet  thick.  There  is  some- 
thing like  definite  succession  of  beds,  as  exhibited  by  well  records, 
but  the  sandstones  and  shales  replace  each  other  abruptly,  so  that  the 
log  of  one  well  may  be  unlike  that  of  one  on  an  adjoining  location. 
Thirty -foot  sand. — The  first  sand  below  the  Big  Injun  which  is  rec- 
ognized at  all  commonly  in  Greene  Count}r  is  known  as  the  Thirty-foot. 
Its  average  distance  below  the  Pittsburg  coal  is  about  1,800  feet.  It 
is  not  productive  anywhere  in  this  locality  so  far  as  known,  nor  does 
its  name  mean  much  as  to  its  thickness,  for  records  show  variations 
from  20  to  60  feet.  The  horizon  of  the  Thirty-foot  is  not  the  same  as 
in  Armstrong  Count}^,  but  probably  corresponds  with  what  is  some- 
times known  there  as  the  Gas,  Butler,  or  Murraysville  sand.  Some- 
where between  the  Thirty-foot  and  the  Big  Injun  there  is  an  occasional 
development  of  a  sandstone  which  has  been  recognized  and  recorded 
in  a  few  logs  as  the  Squaw  sand.  Its  presence  beneath  this  territory, 
however,  is  not  well  enough  known  to  be  affirmed. 
Gantz  and  Fifty-foot  sands. — At  an  average  distance  of  1,916  feet 
below  the  Pittsburg  coal  the  Gantz  sand  is  struck.  It  is  usually  15  to 
25  feet  thick,  and  produces  both  gas  and  oil.  It  is  so  closety  under- 
lain by  the  Fifty-foot  sand  that  the  two  are  frequently  recorded  as 
continuous.  It  is  very  probable  that  the  shale  between  these  two  sands 
becomes  very  thin  in  some  localities,  and  gives  way  to  shal}7  sandstone. 
In  such  cases  the  driller  records  a  thickness  of  60  to  100  feet  for  one 
of  the  sands,  and  makes  no  mention  of  the  other. 
The  horizon  of  these  sands  is  occupied  in  Armstrong  and  other  coun- 
ties by  a  heavy,  continuous  deposit  known  as  the  Hundred- foot  sand,  a 
term  which  is  little  used  in  Greene  County.  The  Gantz  sand  takes  its 
name  from  a  well  on  the  Gantz  farm,  Franklin  Township,  Washington 
County,  Pa.,  which  was  drilled  in  1885,  and  was  the  first  paying  oil 
well  in  the  county. 
Gordon  sand. — A  sand  which  occasionally  produces  a  small  amount 
of  gas,  and  lies  at  an  average  distance  of  2,117  feet  below  the  Pitts- 
burg coal,  has  a  thickness  of  15  to  50  feet,  and  is  usually  recorded  in 
Bull.  225—04 26 
