312  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   1905. 
of  this  coal  shows  a  moderate  amount  of  fixed  carbon  and  volatile  matter,  with  relatively 
low  percentages  of  water  and  ash.     A  section  at  the  Silver  Tip  mine  is  here  given: 
Section  at  Silver  Tip  mine,  on  Cottonwood  Creek,  Wyoming. 
Foot. 
Gray  compact  sandy  clay 4 
Brown  leaf-bearing  shale 3 
Coal 5 
Gray  sandstone G 
Impure  coal  with  streaks  of  leaf-bearing  shale 2 
Dark-coloml  sa  ndstone 5 
Woodruff  mine. — During  the  summer  of  1904  an  opening  was  made  on  a  bed  of  coal  in 
the  upper  part  of  the  Laramie  format  ion  near  the  mouth  of  Meeteetse  Creek,  about  2  miles 
north  of  Meeteetse,  Wyo.  The  seam  is  4  feet  thick  with  no  partings.  It  is  overlain  by 
hard  gray  sandstone  and  underlain  by  a  dark-colored  compact  clay.  An  entry  1,50  feet  deep 
has  been  driven  on  the  scam,  with  several  large  rooms  on  either  side.  The  coal  is  hard  and 
black,  with  a  bright  luster.  It  appears  not  to  break  up  badly  on  exposure,  and  as  a  domestic 
coal  is  said  to  be  very  satisfactory.  No  analysis  has  been  made  of  this  coal.  During  the 
past  two  years  the  Woodruff  mine  has  had  a  total  output  of  2,200  tons,  which  sells  at  $2.25 
per  ton.     The  coal  finds  a  ready  market  at  Meeteetse,  Wyo. 
Erskin  mine. — Another  mine,  which  is  owned  by  Mr.  Erskin,  has  recently  been  opened 
nea i-  Meeteetse,  Wyo.  It  is  located  in  sec.  13,  T.  48,  R.  101,  about  2\  miles  above  Meeteetse, 
in  the  low  land  of  Gray  Bull  Valley.  This  mine  is  on  the  same  seam  which  has  been  worked 
for  many  years  on  the  north  side  of  Gray  Bull  River,  known  as  the  Edward  Blake  mine.  The 
coal  beds  have  a  dip  of  6°  E.,  and  are  somewhat  thicker  than  on  the  opposite  side  of  the 
valley.  The  output  for  last  season  during  the  period  of  development  of  the  mine  was  about 
700  tons. 
No  Wood  coal. — An  opening  has  been  made  in  a  coal  bed  which  outcrops  near  the  base  of 
a  prominent  hill  at  the  head  of  Bud  Kimball  Draw,  14  miles  southwest  of  Tenslecp,  Wyo. 
Coal  is  not  mined  here  regularly,  but  many  of  the  settlers  along  No  Wood  Valley  obtain 
their  fuel  supply  from  this  place.  The  coal  bed,  which  occurs  in  the  lower  part  of  the  Lar- 
amie formation,  has  an  aggregate  thickness  of  about  6|  feet,  consisting  of  fiour  benches 
separated  by  partings  of  bony  coal  and  brown  leaf-bearing  shale. 
Section  of  No  Wood  coal  near  head  of  Bud  Kimball  Draw,  Wyoming. 
Ft.  in. 
Brown  leaf-oearing  shale. 
Very  impure  coal 10 
Gray  sandstone 4 
Coal  containing  thin  layers  of  bone 3  G 
Brown  leaf-bearing  shale 10 
Bony  coal 3 
Coal 9 
Bony  coal 4 
Coal 1  6 
Bony  coal f, 
Coal 1  0 
BENTONITE. 
Bentonite  deposits  occur  at  various  places  throughout  the  Bighorn  Basin.  Those  of  most 
common  occurrence  are  in  the  Colorado  formation,  being  found  at  two  or  more  geologic 
horizons.  The  thickest  deposit  observed  is  in  a  series  of  dark  shaly  beds  about  100  feet 
below  the  Mowry  beds.  The  bentonite  at  this  horizon,  in  the  northern  part  of  the  Bighorn 
Basin,  has  been  described  by  the  writer  in  a  previous  bulletin.  «     During  the  last  field 
«  Fisher,  Cassius  A.  Bentonite  deposits  of  Wyoming:  Bull.  U.  S.  Geol.  Survey  No.  225,  1904,  p.  559. 
