ashley.J  CUMBERLAND    GAP    COAL    FIELD,    KY.-TENN.  271 
Section  of  Kellioka  coal  on  Poor  Fork. 
Sandstone  roof.  Ft,  In. 
Sandy  shale  (4  inches) . 
Coal 0  3 
Shale 1  5 
Coal 0  9 
Coal,  bony 0  5 
Coal 0  5 
Coal,  bony 0  1 
Coal 0  3 
Coal,  bony 0  1$ 
Coal 4  0 
Total 7    8£ 
On  the  whole  this  bed  gives  promise  of  much  workable  coal,  but, 
unless  future  exploration  reveals  better  sections  than  those  now  known, 
large  areas  of  it  will  not  be  workable. 
Coals  of  but  little  more  than  workable  thickness  have  been  found  at 
a  number  of  other  horizons  between  the  Neal  and  Harlan  coals,  but 
they  are  either  thin  at  other  places  or  have  escaped  observation,  so 
that  they  must  at  present  be  considered  as  generally  not  workable  or 
as  unproved. 
Harlan  coal. — As  far  as  our  present  knowledge  goes,  this  is  the  most 
valuable  coal  in  the  eastern  part  of  the  field.  Its  position,  low  in  the 
mountains,  has  led  to  its  being  opened  up  for  local  use  at  a  large  num- 
ber of  points  scattered  all  along  the  banks  of  the  three  forks  of  Cum- 
berland River.  Measurements  at  these  openings  show  the  coal  to 
maintain  a  good  workable  thickness,  at  least  in  all  the  area  drained  by 
the  three  forks  of  Cumberland  River,  in  the  district  here  discussed. 
Between  Wallin  Creek  and  Puckett  Creek  it  is  somewhat  thinner,  or 
else  has  not  been  found.  Between  Puckett  and  Yellow  creeks  occurs 
a  coal  of  good  workable  thickness  at  what  is  believed  to  be  the  same 
horizon,  and  it  will  therefore  be  discussed  under  this  head. 
Its  thickness  between  Puckett  and  Yellow  creeks  may  be  indicated 
by  one  section  giving  the  thicker  developments  which  it  shows  in 
places,  and  by  two  showing  the  average  development. 
Section  of  Harlan  coal  on  Williams  Creek  {above  average  thickness) . 
Clay -shale  roof.  Ft.  in. 
Coal,  weathered 0  S 
Coal 1  0 
Coal,  soft i ------ 0  I 
Coal 0  9 
Clay 0  L| 
Coal... 3  4 
Total - 5     lOf 
