THE  CUMBERLAND  GAP  COAL  FIELD  OF  KENTUCKY  AND 
TENNESSEE. 
By  George  H.  Ashley. 
GENERAL   DESCRIPTION. 
Location  and  limits. — The  Cumberland  Gap  coal  field  forms  part  of 
the  eastern  edge  of  the  Appalachian  coal  field  in  southeastern  Kentucky 
ind  northern  Tennessee.  It  lies  between  Pine  and  Cumberland  moun- 
tains, and  extends  from  Fork  Mountain  to  the  heads  of  Poor  and  Clover 
forks  of  Cumberland  River,  having  a  length  of  90  miles  and  a  width 
Df  from  15  to  20  miles.  These  boundaries  are  not  merely  topographic, 
for  associated  with  Pine  and  Fork  mountains  are  notable  faults,  mak- 
ing distinct  breaks  between  this  field  and  the  coal  fields  to  the  west 
Ind  north;  and  while  this  field  was  originally  part  of  the  same  general 
3oal  field,  as  are  the  coal  areas  to  the  west  and  north,  more  detailed 
work  than  has  yet  been  done  will  be  required  to  connect  the  stratig- 
raphy  of  this  basin  with  that  of  the  outside  fields,  or  to  correlate  the 
3oals  across  the  breaks  made  by  the  faults  mentioned.  Cumberland 
Mountain  forms  the  eastern  escarpment  of  the  Appalachian  coal  field, 
ill  that  part  of  the  Coal  Measures  that  may  formerly  have  existed  to 
the  south  having  been  removed  by  erosion.  This  paper  is  based  on 
field  work  in  the  seasons  of  1902  and  1903  over  the  central  part  of  the 
basin,  or  the  area  lying  between  Log  Mountains  at  the  head  of  Yellow 
Creek  to  a  north-south  line  about  10  miles  east  of  Harlan.  The  data 
presented,  therefore,  are  not  authoritative,  except  within  those  limits. 
Topography. — Pine  and  Cumberland  mountains  are  formed  by  the 
Bdges  of  resistant  sandstones  upturned  at  angles  of  from  20°  to  90° 
from  the  horizontal,  and,  following  the  structure,  run  nearly  straight 
on  northeast-southwest  lines.  Between  them  lies  a  mass  of  mountains 
of  irregular  shapes,  with  irregular  and  usually  narrow  crests. 
The  drainage  of  the  area  studied  is  entirely  into  Cumberland  River, 
which  is  formed  by  the  union  of  the  three  forks — Poor,  Clover,  and 
Martins — at  Harlan,  and  which  escapes  from  the  basin  by  the  gap  at 
Pineville.  Wallin,  Puckett,  Yellow,  and  Clear  creeks  are  its  principal 
tributaries  below  the  forks.     At  the  Pineville  Gap  Cumberland  River 
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