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CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1905. 
thickness  from  4  to  20  feet  and  in  a  few  instances  more  than  20  feet.  The  coal  is  usually 
free  from  shaly  impurities  and  is  massive.  So  pronounced  is  the  massive  nature  where 
the  coal  is  fresh  that  seams  or  lines  indicating  stratification  are  scarcely  discernible.  It 
mines  in  irregular  blocks,  often  of  large  size.  A  bed  15  to  20  feet  thick  is  inclined  to 
spall  in  large  irregular  slabs  several  feet  in  extent  across  the  bedding.  The  coal  is  not 
usually  affected  nor  does  it  slack  to  any  appreciable  extent  on  exposure  to  weathering 
agents.  It  is  black  and  for  the  most  part  has  a  bright  luster.  It  usually  contains  small 
irregular  inclusions  of  a  yellowish,  brittle,  resin-like  bituminous  substance  scattered  here 
and  there  that  yields  an  asphaltic  odor  on  ignition.  The  following  proximate  chemical 
analyses  give  a  fair  idea  of  the  composition  of  the  coals.  The  samples  for  analysis  were 
collected  from  the  several  beds  in  the  lower  part  of  the  coal-bearing  section  and  from 
localities  scattered  between  Huntington  Canyon  in  the  Wasatch  Plateau  and  Horse  Can- 
yon, a  point  60  miles  distant  in  the  Book  Cliffs  southeast  of  Sunnyside.  The  method  of 
selecting  samples  of  coal  for  analyses  is  as  follows:  A  clean  surface  of  the  whole  bed  at  the 
face  of  the  working  is  selected,  or  a  section  of  about  6  inches  in  width  is  made  clean  by 
removing  the  surface.  Then  a  channel  3  to  4  inches  in  width  and  of  even  depth  is  cut 
down  the  cleaned  surface,  so  that  an  equal  amount  of  coal  is  obtained  for  each  unit  of  a 
section.  This  coal  so  removed  is  placed  on  a  clean  surface  and  immediately  broken  to 
lumps  half  an  inch  and  less  in  diameter  and  thoroughly  mixed.  The  sample  is  then  quar- 
tered, opposite  quarters  being  taken  and  remixed.  The  quartering,  selecting,  and  mixing 
process  is  continued  until  the  sample  is  reduced  to  about  1  quart,  which  is  placed  in  a 
galvanized-iron  can,  sealed,  and  shipped  to  the  laboratory. 
The  Book  Cliffs  coals  are  clearly  within  the  bituminous  grade,  and  are  remarkably 
uniform  in  composition.  The  sulphur  content  is  also  uniform  and  low,  the  average  being 
a  little  above  one-half  of  1  per  cent. 
Proximate  analyses  of  coals  from  the  Book  Cliffs  coalfield,  Utah.a 
No. 
Location. 
Moisture, 
Volatile 
matter. 
Fixed 
carbon. 
Ash. 
Sulphur. 
52.09 
4.99 
0.74 
52.  75 
5.84 
.60 
51.68 
7.17 
.78 
52.94 
3.88 
.54 
52.59 
5.26 
.48 
52.16 
6.10 
.54 
48.45 
7.70 
.49 
45.45 
8.35 
.56 
45.91 
5.78 
.86 
45.80 
5.29 
.57 
46.91 
4.01 
.31 
48.40 
6.60 
.83 
46.09 
4.28 
.48 
50.42 
7.76 
2.06 
Loss  of 
moisture 
on  air 
drying. 
Horse  Canyon,  sec.  4  (?),  T.  16  S.,  R. 
14  E 
Upper  bed,  No.  lmine,  Sunnyside. . . 
Average  of  crushed  coal,  prepared  for 
coking,  from  all  mines,  Sunnyside. . 
DugoutCanyon,  sec.23,  T.  13  S.,  R.  12  E 
Bean  prospect,  Coal  Creek  Canyon, 
sec.  10,  T.  13  S.,  R.  11  E 
Gilson  prospect,  Coal  Creek  Canyon, 
sec.  3,  T.  13  S.,  R.ll  E 
Western  part  of  Castlegate  mine 
Eastern  part  of  Castlegate  mine 
No.  1  mine,  Winterquarters 
Clear  Creek  mine,  Clear  Creek 
Huntington    Canyon,    Bear    Gulch 
prospect,  NE.  \,  sec.  11,  T.  14  S.,  R. 
Huntington  Canyon,  near  center  of 
S.  %  sec.  24,  T.  16  S.,  R.  7  E 
Larsen  Brothers'  mine,  sec.  2,  T.  15  S., 
R.  6E 
Emery  coal  mine,b  sec.  2,  T.  23  S.,  R. 
6E 
4.76 
3.37 
3.43 
4.98 
5.42 
4.72 
6.13 
8.10 
7.02 
8.46 
5.11 
38.16 
38.04 
37.  72 
38.20 
38.06 
36.32 
39.  13 
40.07 
40.21 
41.89 
5.19  43.89 
6.04  38.96 
41.17 
36.71 
1.00 
1.30 
1.50 
2.40 
1.10 
1.00 
1.30 
3.50 
3.90 
3.10 
2.30 
2.90 
3.50 
a  These  analyses  were  made  by  the  United  States  Geological  Survey  coal-testing  plant  at  St.  Louis. 
F.  M.  Stanton,  analyst. 
b  The  Emery  coal  is  in  the  sandstone  of  the  Red  Plateau,  1,500  feet  or  more  stratigraphically  below 
the  Book  Gluts  coals. 
