236         CONTRIBUTIONS   TO   ECONOMIC  GEOLOGY,   1907,   PART  II. 
Sections  of  coal  beds  of  the  Wasatch  formation — Continued. 
No.  on 
PI. 
XII. 
Location. 
Section  of  coal  bed. 
Remarks. 
Sec.                 T. 
R. 
01 
NE.  |SW.  \. 
19 
22 
93 
Ft.  in. 
Shale 8 
Coal 5 
Shale,  carbonaceous ...    3    4 
Coal 1    5 
Bone 10 
Coal 3    7+ 
Surface  prospect. 
10    3+ 
(12 
NW.  \  SW.  £. 
3 
20 
93 
Shale 3 
Coal 2  11 
Coal,lignitic,brown    1    4 
Sandstone 2    1 
Surface  prospect. 
9    4 
'i3 
Center. 
14 
20 
93 
Sandstone 2 
Coal 10    3 
Shale 7 
Coal,  impure 2 
Shale 1 
Coal,  impure 3  10 
Surface  prospect. 
18    9 
64 
SE.JSE.J. 
14 
20 
93 
Shale 7 
Coal 1 
Shale 1 
Coal 6 
Surface  prospect. 
7    8 
65 
SW.  iSW.i. 
32 
21 
92 
Shale. 
Coal,  very  impure  .    1 
Coal,  fair 4    1 
Surface  exposure. 
5    1 
66 
SE.  JSE.i. 
7 
20 
92 
Shale,  carbonaceous. . .    4 
Coal .-.    3    9 
Shale,  carbonaceous. . .    1 
Surface  prospect. 
8    9 
QUALITY  OF  THE  COAL. 
PHYSICAL   PROPERTIES. 
The  quality  of  the  coal  of  this  area  is  very  poorly  shown  by  the 
analyses  of  samples  collected  within  the  field  itself.  Nowhere  has 
development  been  carried  beyond  the  zone  of  surface  alteration. 
The  coal  of  Mesaverde  age  is  not  exposed  in  this  field  except  at  the 
abandoned  mine  in  sec.  22,  T.  21  N.,  R.  88  W.,  and  at  a  few  small 
surface  outcrops  near  Bull  Springs.  It  is  so  badly  weathered  that 
its  physical  properties  could  not  be  studied.  The  remaining  coals 
weather  very  rapidly.  Several  slopes  have  been  driven  to  distances 
of  about  75  feet  in  beds  of  the  different  zones,  but  the  surfaces  exposed 
in  these  slopes  are  badly  weathered.  Apparently  fresh  blocks  of  coal, 
obtained  beneath  the  weathered  surface,  on  exposure  to  the  direct 
rays  of  the  sun  rapidly  break  up  independently  of  the  joint  planes 
into  smaller  and  smaller  fragments  with  irregular  faces,  until  the 
final  fragments  are  about  the  size  of  a  pea.  The  original  blocks  have 
a  bright  luster  and  many  of  them  a  slight  conchoidal  fracture.  The 
resultant  fragments  are  lusterless,  and  their  surfaces  do  not  show  an 
