OIL  AND  GAS  FIELDS  OF  EASTERN  GREENE  COUNTY,  PA. 
By  Ralph  W.  Stone. 
INTRODUCTION. 
The  purpose  of  this  paper  is  to  present  at  an  early  date  what  is 
known  concerning  the  geologic  structure  in  the  territory  described  and 
the  distribution  of  the  oil  and  gas  fields  with  relation  to  the  structure. 
A  geologic  survey  has  been  made  of  all  of  the  field  except  a  strip  south 
of  Dunkard  Creek,  which  is  a  blank  on  the  accompanying  sketch  map 
(%.  ii). 
Location. — Greene  County  occupies  the  southwest  corner  of  the 
State  of  Pennsylvania,  and  extends  eastward  to  Monongahela  River. 
It  is  bounded  on  the  north  by  Washington  County,  on  the  east  by 
Fayette  County,  and  on  the  south  and  west  by  West  Virginia.  The 
western  edge  of  the  sketch  map  is  the  western  boundary  of  the 
Waynesburg  quadrangle 
TOPOGRAPHY. 
The  surface  relief  of  Greene  County  is  characteristic  of  a  consider- 
able portion  of  western  Pennsylvania.  The  region  is  hilly,  with  no 
strong  features,  and  everywhere  the  general  character  of  the  topog- 
raphy is  that  of  mature  dissection.  The  difference  in  elevation  between 
Monongahela  River  and  the  highest  hilltops  is  less  than  900  feet.  All 
of  the  drainage  is  tributary  to  Monongahela  River,  so,  in  a  general 
way,  this  half  of  the  country  has  an  eastward  slope. 
GEOLOGY. 
The  rocks  which  are  exposed  at  the  surface  in  the  eastern  half  of 
Greene  County  are  limited  to  the  Monongahela  and  Dunkard  forma- 
tions and  a  small  portion  of  the  Conemaugh  formation.  The  Pittsburg 
coal,  which  is  the  base  of  the  Monongahela  or  Upper  Productive 
series,  outcrops  just  above  water  level  at  the  mouth  of  Tenmile  Creek, 
and  is  seen  in  the  river  bluff  from  Cats  Creek  southward  to  beyond 
the  State  line,  and  on  Dunkard  Creek  for  about  2  miles  from  its 
mouth. 
Monongahela  formation.— The  Upper  Coal  Measures  are  from  320 
to  380  feet  thick  in  this  area,  thinning  toward  the  west.     The  forma- 
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