278  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1905. 
South  of  Glen  Campbell  and  Smithport,  between  Susquehanna  River  and  Little  Mahoning 
Creek,  nearly  all  the  mining  appears  to  be  on  one  seam,  which  is  tentatively  correlated  wit! 
the  "D"  coal.     It  presents  a  remarkably  persistent  section.     Nearly  every  mcasurernenl 
made  on  it  shows  from  3  to  9  inches  of  bony  coal  at  the  top,  in  places  resembling  canne 
coal;  then  a  main  bench  of  coal  from  3  feet  to  3  feet  8  inches  thick,  a  shale  parting  1  to  £  ] 
inches  thick,  and  a  lower  bench  of  coal  from  3  to  6  inches  thick.     The  roof  is  always 
shale.     At  most  points  neither  the  drillings  nor  road  sections  show  any  coal  above  that  ' 
being  worked,  so  that  that  bed  has  been  widely  correlated  with  the  "E"  coal.     At  a  few  I 
points  there  appears  to  be  a  coal  above,  and  as  this  coal  seems  to  connect  with  the  "D  "  coal  j 
around  Glen  Campbell  it  has  been  correlated  tentatively  with  the  "D"  coal,  as  stated 
above.     The  Mahoning  sandstone  can  not  certainly  be  recognized  in  this  area  and  therefore 
does  not  help  in  solving  the  problem. 
To  judge  from  the  openings  made  on  this  coal,  it  will  be  persistently  workable  under  all 
of  the  area  within  its  outcrop  south  and  southwest  of  Glen  Campbell  to  Little  Mahoning  1 
Creek,  and,  as  it  is  below  drainage  over  much  of  the  center  of  the  Glen  Campbell  basin,  it  « 
will  present  a  large  body  of  workable  coal. 
Below  this  coal  there  appear  to  be  at  least  two  coals  which  are  locally  or  generally  work- 
able The  first  occurs  about  50  feet  below  and  shows  a  thickness  of  from  2  to  oxer  3  feet. 
It  is  a  solid  coal  and  has  been  opened  at  a  few  points  along  the  drainage  of  Little  Mahoning 
Creek.  At  a  distance  of  from  134  to  178  feet  lower  drillings  show  coals  which  are  locally 
from  3  to  4  feet  thick,  though  some  drillings  fail  to  find  more  than  a  few  inches  of  coal  at 
these  depths.  It  does  not  appear  certain  that  these  lower  coals  are  all  at  the  same  horizon. 
Tentatively  they  have  been  assumed  to  be  such  and  have  been  correlated  with  the  "B" 
coal.  The  "B"  coal  outcrops  on  Ilortons  Run  just  west  of  Glen  Campbell  and  along  the 
valley  of  Little  Mahoning  Creek,  in  both  of  which  areas  it  shows  a  workable  thickness. 
Aside  from  these  exposures  this  bed  is  below  drainage  over  all  of  this  basin,  as  well  as 
below  the  anticlinal  arch.  If  further  prospect  ing,  therefore,  shows  it  to  ma  in  tain  a  workable 
thickness,  it  may  be  counted  on  to  yield  a  large  amount  of  coal  in  the  future. 
LITTLE    MAIIONINO     (REEK     DISTRICT. 
Under  this  heading  may  be  considered  the  coal  in  the  drainage  of  Little  Mahoning  Creek 
from  Richmond  to  Deckers  Point.  The  Pottsville  sandstone  outcrops  in  the  bottom  of 
the  \  alley  bet  ween  points  below  Richmond  and  above  Nashville.  From  50  to  100 feet  above 
the  sandstone  through  all  of  this  districl  lies  the  "B"  coal,  which  locally  shows  a  thickness 
of  over  1  feet  to  the  north  of  Richmond  and  of  3  feet  in  the  valley  above  Nashville.  Around 
Roberts  this  coal  appears  to  be  too  thin  and  broken  up  to  be  worked.  Just  south  of  Rich- 
mond a  coal,  which  appears  to  be  either  the  "B"  or  "C,"  reaches  a  thickness  of  from  5  feet 
to  5  feet  3  inches  and  is  overlain  by  5  or  6  inches  of  bony  coal.  The  "C"  coal  shows  a 
thickness  in  the  hills  southeast  of  Richmond  of  from  2  feet  8  inches  to  3  feet  of  coal,  with 
1  inch  of  shale  4  inches  from  the  bottom.  Above  it  the  "C"  coal  has  been  opened  at 
several  points  and  shows  a  variable  thickness,  sometimes  as  great  as  4  feet.  The  "D'' 
sea  in  appears  to  have  been  opened  at  several  points  and  shows  from  24  to  4  feet  of  coal,  in 
all  cases  apparently  overlain  by  a  few  inches  of  bone,  which  locally  may  thicken  to  as 
much  as  14  inches.  The  "E"  bed  has  been  opened  at  a  number  of  points  and  locally  shows 
3  feet  of  coal.  In  all  of  this  district  the  data  on  the  coal  are  so  scattered  that  it  can  not 
safely  be  stated  how  large  bodies  may  be  found  of  the  thicknesses  given.  From  what 
has  been  seen  of  the  coal,  however,  it  seems  safe  to  predict  that  the  district  will  yield  a 
fairly  large  amount  of  workable  coal,  notwithstanding  the  fact  that,  owing  to  the  presence 
of  the  anticlines,  the  coals  lie  high  in  the  hills  as  compared  with  the  two  preceding  districts. 
DEVELOPMENT. 
The  Punxsutawney  field  is  characterized  by  a  few  large  mines  rather  than  many  small 
ones.  These  mines,  if  not  the  largest,  are  among  the  largest  in  the  State  of  Pennsylvania, 
which  places  them  among  the  largest  in  the  United  States.     The  Adrian,  Florence,  and 
