COAL  MINING  ALONG  THE  SOUTHEASTERN  MARGIN  OF  THE 
WILMORE  BASIN,  CAMBRIA  COUNTY,  FA. 
By  Charles  Butts. 
For  many  years  coal  mining  has  been  carried  on  actively  along-  the 
main  line  of  the  Pennsylvania  Railroad  east  of  Johnstown,  Pa.  It  is 
probable  that  the  early  development  of  this  field  was  not  due  to  thicker 
beds  and  better  quality  of  coal  than  in  the  surrounding  region,  but  to 
better  transportation  facilities  to  the  seaboard  and  to  the  manufactur- 
ing cities  of  the  East.  The  scene  of  greatest  development  extends 
from  the  village  of  South  Fork,  situated  at  the  mouth  of  the  stream 
"of  the  same  name,  to  Bennington,  which  lies  at  the  eastern  end  of  the 
Pennsylvania  Railroad  tunnel  that  marks  the  extreme  summit  of  the 
Allegheny  Mountains. 
Structure. — The  Wilmore  basin  consists  of  a  comparatively  long 
and  narrow  synclinal  trough  lying  parallel  with  and  just  west  of  the 
Allegheny  front.  The  basin  is  so  deep  that  the  principal  coal-bearing 
beds,  which  are  exposed  on  the  eastern  side,  lie  far  below  water  level 
in  the  center  of  the  basin,  and  even  on  the  northwestern  side  are 
seldom  exposed  except  in  the  valley  of  Conemaugh  River,  near  the 
town  of  South  Fork.  Mining  operations  so  far  have  been  confined 
almost  exclusively  to  the  outcrop  of  the  coal  beds  on  both  sides  of  the 
basin,  and  in  many  places  the  coal,  which  was  easily  available,  has  been 
mined  out.  The  operations  are  now  approaching  the  center  of  the 
basin,  and  the  time  is  not  far  distant  when  the  interior  parts  of 
the  field  will  be  the  scenes  of  greatest  activit}^ 
Geologic  work. — In  anticipation  of  this  condition,  the  present  survey 
of  a  portion  of  the  Wilmore  basin  was  undertaken  with  the  hope  of 
showing,  by  means  of  contour  lines  on  some  important  bed  of  coal,  the 
depth  at  which  it  may  be  found  in  all  parts  of  the  basin,  and  also  the 
form  and  shape  of  the  basin  itself.  The  western  side  of  the  basin  was 
not  examined  during  the  present  survey,  but  part  of  the  eastern  side, 
including  mines  in  the  vicinity  of  Bennington,  Gallitzin,  Cresson,  Lilly., 
Bens  Creek,  Portage,  Lloydell,  and  Dunlo,  was  examined  with  con- 
siderable care. 
Stratigrajyhic  relations. — The  coal-bearing  rocks  involved  in  the 
Wilmore  basin  are  known  as  the  Allegheny  formation,  or  Lower  Pro- 
ductive Coal  Measures.     The  top  of  the  formation  is  marked  by  the 
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