158         CONTKIBUTTONS    TO    ECONOMIC    GEOLOGY,   1907,   PABT   II. 
3  feet  thick  are  present  wherever  the  sandstone  occurs.     The  follow-, 
ing  is  a  typical  section: 
Section  of  coal  beds  in  white  sandstone  on  north  side  of  North  Platte  River,  4  miles  east 
of  Casper. 
J          y  Ft.    in. 
Shale,  carbonaceous 3 
Sandstone,  yellowish  white 6 
Coal 2 
Sandstone,  white 25 
Coal 2  10    . 
Sandstone,  white 3 
Shale,  sandy,  carbonaceous 6 
47  10 
COAL  BEDS  OF  THE  FORT  UNION  (?)  FORMATION. 
The  Fort  Union  (?)  formation  contains  two  coal  zones  of  importance 
and  traces  of  coal  at  a  number  of  other  horizons.  The  most  exten- 
sive coal  mining  of  the  region  is  being  done  on  the  beds  of  the  Big 
Muddy-Glenrock  zone,  at  the  base  of  this  formation.  The  coal  beds 
are  probably  not  identical  at  these  two  places,  but  they  occur  in. the 
same  zone  and  are  not  far  apart  stratigraphically.  At  Big  Muddy 
two  beds  are  worked,  one  4  feet  8  inches  thick  and  the  other  3  feet  6 
inches.  At  Glenrock  only  one  bed  is  worked  to  any  extent;  it  is 
more  than  5  feet  thick.  The  localities  where  the  coal  belonging  to 
this  zone  may  be  seen  are  shown  on  the  map  (PL  IX).  One  very 
good  outcrop  is  on  Cole  Creek,  in  sec.  31,  T.  34  N.,  R.  76  W.  Another 
is  on  the  north  bank  of  the  river,  near  the  southwest  corner  of  T.  34 
N.,  R.  75  W.  In  the  southeastern  part  of  the  field  this  coal  is  cov- 
ered with  the  white  Tertiary  clays  and  conglomerate  to  a  depth  of 
1  to  600  feet.  The  following  section,  showing  the  coal  beds  in  this 
zone,  has  been  furnished  by  the  Glenrock  Coal  Company: 
Section  showing  strata  passed  through  by  diamond  drill  at  the  northeast  corner  of  the  SE.  \ 
NE.  i  sec.  4,  T.  33  N.,  R.  75  W.,  Glenrock,  Wyo. 
Ft.  in. 
Surface  soil 3 
Sand  and  gravel 7 
Shale,  sandy 28 
Sandstone,  soft 9  10 
Shale,  sandy 41  10 
Soapstone 8    2 
Sandstone 2 
Soapstone 3 
Sandstone 5    8 
Slate,  black 4 
Coal : 2 
Coal,  bony 2 
Fire  clay 4 
Sandstone,  hard 8 
