MILES    CITY    COAL   FIELD,    MONTANA. 
Section  of  coal  bed  at  Weaver  mine  near  Signal  Butte,  sec.  6,  T.  7  N.,  R.  48  E 
Ft.  in. 
( lay,  brown,  carbonaceous 10 
Coal 2     2 
-     Clay 1 
Coal 2 
Clay 3 
Coal 1    5 
Clay,  carbonaceous 4 
Coal 1    2 
Clay. 
Total  coal 4  11 
Only  the  two  upper  benches  are  mined. 
North  of  Signal  Butte  the  Tongue  River  badlands  contain  no  expo- 
sures of  this  bed  that  indicate  a  workable  thickness. 
On  Cottonwood  Creek,  in  T.  8  N.,  Rs.  49  and  50  E.,  a  bed  at  this 
horizon  was  traced  for  many  miles,  but  nowhere  shows  a  thickness 
exceeding  2  feet  8  inches.  The  coal,  however,  appears  to  be  of  good 
quality  and  will  doubtless  be  mined  to  some  extent  for  local  supply. 
West  of  Powder  River,  near  the  head  of  Laney  Creek,  in  T.  7  N., 
Rs.  50  and  51  E.,  a  bed  at  or  near  this  horizon  overlies  the  Laney  coal 
and  is  regarded  as  workable  for  several  miles  along  its  outcrop,  where 
it  contains  approximately  3  feet  of  coal  without  partings.  East  of 
Powder  River  no  exposures  of  this  bed  were  seen  in  which  the  coal 
could  be  regarded  as  workable. 
LIGNITES    OF    THE    UPPER    MEMBER. 
GENERAL    OUTLINE. 
The  lignites  of  the  upper  beds  are  dark  brown  in  color,  usually  tough 
and  woody  in  texture,  but  relatively  uniform  in  distribution  and 
purity.  In  these  respects  they  differ  considerably  from  the  black, 
nearly  textureless  coals,  already  described.  Valuable  beds  are  found 
generally  at  two  horizons,  the  lower  of  which  is  160  feet  above  the 
base  of  the  upper  member;  the  upper  about  300  feet  above  the  base. 
These  horizons  are  indicated  on  the  map  and  section  (PL  III)  by  the 
letters  E  and  F.  In  the  field  their  outcrops  are  indicated  by  clinkers, 
and  there  are  large  areas  in  which  the  lignite  has  been  wholly  destroyed 
by  fire. 
In  addition  to  these  more  important  lignite  horizons  there  are  many 
thin  beds,  one  of  which,  about  70  feet  above  the  base  of  the  member, 
is  thick  enougli  to  work  in  at  least  two  places.  It  measures  slightly 
over  3  feet  in  sec.  28,  T.  7  N.,  R.  49  E.,  and  4  feet  at  the  Hill  ranch, 
in  sec.  27,  T.  8  N.,  R.  50  E.  These  occurrences  are  regarded  as  local, 
however,  as  no  lignite  beds  thicker  than  1  foot  have  been  discovered 
elsewhere  at  or  near  this  horizon. 
