298  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY.  1905. 
south  end  of  the  coal  workings,  exposing  about  30  feet  of  strata  above  the  coal  in  the  mi  e 
including  three  beds  of  coal.  The  lowest  of  these  beds  is  14  inches  thick,  the  middle  5  fi  j 
3  inches,  and  the  uppermost  9  feet.  The  coal  of  the  two  thicker  beds  appears  to  be  of  f  i 
quality. 
Winterquarters  mines. — Coal  is  being  mined  on  a  large  scale  in  the  south  side  of  the  cany  i| 
at  Winterquarters,  which  is  located  in  the  E.  \  sec.  1,  T.  13  S.,  R.  6  E.,  and  the  W.  \  see  5 
T.  13  S.,  R.  7  E.     The  coal  in  mine  No.  1  now  in  operation  varies  in  thickness  from  9  feet  J 
the  entrance,  near  the  center  of  the  east  side  of  sec.  1,  T.  13  S.,  R.  6  E.,  to  16  feet  at  t  i 
face  of  the  coal  in  the  southeastern  part  of  fhe  working,  near  the  center  of  sec.  7,  T.  13 !  . 
R.  7  E.     The  coal  is  massive  and  generally  clear  of  shaly  impurities.     Analysis  No.  9  (s  i 
table  above,  p.  294),  made  from  samples  selected  at  the  face  of  the  working  in  the  sout 
eastern  part  of  the  mine  is  almost  identical  with  that  of  the  Castlegate  coal.     The  same  b 
has  been  worked  quite  extensively  from  openings  in  the  north  side  of  the  canyon  at  Wint 
quarters;  also  in  the  south  side  east  of  the  town  and  near  the  center  of  the  W.  \  sec.  6, 
IMS.,  R.  7E. 
Two  distinct  cast -west  faults  were  encountered  in  mine  No.  1.  Along  the  one  on  t  ( 
north  the  downthrow  is  40  feet  on  the  south  and  along  the  other  the  downthrow  is  90  fe  I 
on  the  north.  The  result  is  an  cast -west  dropped  block  a  few  hundred  feet  in  width.  T  | 
coal  rises  toward  the  south  at  an  angle  of  about  3°  and  the  downthrown  block  is  overcoon 
in  mining  by  increase  in  the  grade  of  the  slope. 
The  coal  and  associated  strata  in  mine  No.  1  and  in  the  mine  opposite  on  the  north  side 
the  canyon  are  cut  by  a  number  of  dikes  of  basic  igneous  rocks  bearing  east  and  west .  Tl 
dike  in  the  south  mine,  nearly  150  feet  from  the  entrance,  is  approximately  vertical,  5  f e 
in  width  at  the  floor  and  1  foot  at  the  roof.  It  swells  to  a  width  of  10  feet  in  the  coal  be 
which  is  here  9  feet  thick  and  has  metamorphosed  the  coal,  producing  a  coke-like  substan 
to  a  distance  of  2  to  3  feet  on  each  side.  The  dike  in  the  northern  mine  occurs  about  3( 
feet  from  the  mouth  of  the  slope.  It  is  approximately  10  feet  thick,  and  has  coked  the  cc 
in  a  similar  manner  as  in  mine  No.  1 .  Thin  dikes  of  igneous  rock  1  foot  and  less  in  thickne 
are  reported  by  Superintendent  Thomas  J.  Parmley  to  occur  at  other  places  in  these  minei 
Such  thin  dikes,  it  is  stated,  do  not  metamorphose  the  coal  appreciably. 
Crandall  Canyon-  A  coal  bed  is  mined  for  local  consumption  in  the  SE.  \  SW.  \  sec.  1 
T.  13  S.,  R.6  E.,  near  the  head  of  Crandall  Canyon.  This  canyon  leads  into  Pleasant  Va 
ley  midway  between  Scoficld  and  Clear  Creek.  The  coal  is  approximately  12  feet  thi( 
and  is  massive  and  clean.     It  is  mined  on  the  rise  toward  the  south. 
Clear  Creek  mine. — This  mine  is  in  the  town  of  Clear  Creek,  near  the  head  of  I'leasai 
Valley.  The  Clear  Creek  coal  varies  in  thickness  in  a  north-south  direction  through  tl 
mine  working,  a  length  of  nearly  7,000  feet.  In  the  southern  part  the  coal  is  massive  an 
is  13  feet  .")  inches  thick.  No  shaly  or  other  impurities  were  noted.  Near  the  center  of  tl 
workings  a  thin  shale  parting  enters  the  coal.  Toward  the  north  and  within  a  distance  i 
2,000  feet  the  shale  swells  to  a  thickness  of  16  feet,  dividing  the  coal  into  two  benches.  1 
the  northern  part  of  the  mine,  where  the  shaly  parting  is  thick,  only  the  upper  bench,  4  t 
6  feet  thick,  is  worked. 
Several  small  north-south  faults  occur  near  the  outcrop,  displacing  the  coal  vertical 
from  .5  to  40  feet .  Nearly  2,200  feet  east  of  the  entrance  to  the  mine  a  large  fault  occur; 
bearing  a  few  degrees  east  of  north,  by  which  the  coal  is  displaced  out  of  sight.  The  amour 
of  throw  was  not  determined. 
Coal  was  being  prospected  in  rocks  apparently  above  the  coal-bearing  series  hitherto  recoj 
nized  in  the  SW.  \  sec.  31,  T.  13  S.,  R.  7  E.,  near  the  head  of  the  gulch  bearing  west  froi 
Clear  Creek.  The  coal  bed  is  about  10  feet  thick,  and  it  is  regarded  by  the  prospectors  as  heir 
the  same  as  one  of  the  workable  beds  found  in  Pleasant  Valley,  1 ,000  to  1 ,100  feet  lower  in  tl 
section.  The  rocks  in  this  region,  as  elsewhere  in  the  Book  Cliffs  field,  are  almost  hori/.onta 
and  the  coal  in  Huntington  Canyon  2  miles  southwest  of  the  prospect  is  near  the  same  strat 
graphic  position  and  about  the  same  elevation  above  sea  level  as  the  Clear  Creek  coal.  If  t  r 
position  of  the  coal  near  the  head  of  the  gulch  west  of  Clear  Creek  is  explained  by  faulting,  i 
