ROCK   SPRINGS    COAL   FIELD,    WYOMING. 
265 
deep.  Around  the  margin  there  is  every  evidence  of  very  recent 
slumping.  Along  one  of  the  cracks  a  current  of  hot  air  is  continually 
rising.  The  odor  of  coal  gas  is  very  strong,  and  the  temperature  of 
the  air  at  the  mouth  of  the  crack  is  about  120°.  It  was  impossible  to 
determine  from  the  exposure  how  deep  the  burning  coal  bed  is  located, 
but  it  is  certain  that  it  is  more  than  10  feet  below  the  surface.  A 
short  distance  north  of  this  sink  is  another  large  one  in  which  a  heavy 
white  sandstone  bed  has  dropped  down  15  to  20  feet.  Cracks  in  the 
sandstone  along  the  edge  show  a  depth  of  about  25  feet  without  re- 
vealing burning  coal.  Coal  for  local  ranch  use  is  being  mined  at 
Hooten's  prospect,  in  sec  24,  T.  23  N.,  R.  104  W. 
The  following  representative  sections  illustrate  the  thickness  and 
character  of  the  coal  beds  of  the  Black  Rock  group: 
Sections  of  coal  beds  in  the  Black  Rock  coal  group. 
Location. 
Section  of  coal  bed. 
Location. 
Section  of  co 
Sec. 
T. 
R. 
Sec. 
T. 
R. 
al  bed. 
SW.JNW.J. 
20 
18 
98 
Coal 
Shale 
Coal 
Shale. 
Ft.  in. 
4 
4 
31 
NE.  JSE.  1 
7 
21 
100 
Coal 
Shale 
Coal 
Ft.  in. 
..     1     2 
G 
1     X 
3    4 
11* 
NW.iSW.  i. 
NE.iNE.i. 
34 
21 
100 
Sandstone... 
Coal 
Shale. 
NE.JSW.i. 
29 
18 
98 
Coal 
Shale 
Coal 
Shale. 
4 
4 
.     1 
..     5 
..  25 
30 
1     8 
11 
21 
101 
Sandstone. 
Coal 
Shale. 
18 
18 
34 
18 
99 
Shale. 
Coal 
Shale 
Coal 
Shale. 
4 
.     1     4 
.     1     G 
..2    0 
NE.JSW.  ',. 
SE.iNE.  J. 
7 
21 
104 
Sandstone... 
Coal 
Shale 
..     G 
..     4 
..     1     G 
3    2 
11     0 
Shale. 
Coal 
Shale 
Coal 
Shale. 
SW.i  NW.  ',- 
18 
18 
99 
100 
4 
.     1     2 
.     2    4 
3  10 
NW.JNW.J. 
17 
22 
100 
Shale. 
Coal 
Sandstone... 
..2    6 
..     4 
6    G 
XK.l  SW.J. 
24 
22 
104 
Sandstone. 
Coal 
Shale 
N\V.  >X\V.  ',. 
Shale. 
Coal 
Bone 
Shale. 
.     3    6 
G 
..     3 
..     1 
4 
4 
SK.l  SWi. 
21 
18 
100 
Shale 
Coal 
Shale 
Coal 
..4    7 
NE.JNE.J.      28 
19 
100 
Sandstone. 
Coal 
Shale. 
.  21 
..          1 
..   11 
15  10 
21 
NW.JNE.i 
23 
18 
100 
Coal 
Shale 
Coal 
Shale 
..     1 
2 
..2    3 
..     1     1 
4    6 
NE.JNW.J. 
28 
21 
99 
Shale. 
Coal 
Shale,  sandy  . 
.     2 
.     2 
4 
