NORTH    DAKOTA -MONTANA    LIGNITE    AREA.  319 
The  number  of  lignite  seams  which  may  be  present  in  a  single  section  is  well  exhibited 
t  the  bluffs  of  Little  Missouri  River  5  miles  above  the  mouth  of  Cherry  Creek,  in  nortli- 
estern  Dunn  County,  N.  Dak. 
Section  on  Little  Missouri  River  5  miles  above  Cherry  ( 'reek. 
Ft.    in. 
53.  Clay,  to  top  of  bluff 35 
52.  Lignite 1          3 
51.  Clay,  gray  and  buff 55 
50.  Brown  clay  shale 4 
49.  Lignite 1 
48.  Clay  shale 40 
47.  Lignite,  302  feet  above  river 7-8 
40.  Clay  shale '. 18 
'  45.  Lignite  with  some  clay 10 
44.  Clay  shale 24 
43.  Lignite .' 2          0 
42.  Brown  and  gray  clay  shale 4 
41.  Sandy  clay 6          0 
40.  Clay  shale 3 
39.  Lignite,  240  feet  above  river 4 
38.  Gray  clay  shale 17 
37.  Lignite 10 
30.  Gray  clay 2 
35.  Gray  sand 11 
34.  Sandstone  ledge 2 
33.  Gray  sand 2 
32.  Gray  and  yellow  clay,  flaky 15 
31.  Lignite 4 
30.  Gray  and  yellow  clay;  breaks  into  thin  flakes 4         6 
29.  Lignite 7 
28.  Gray  clay;  crumbles  into  thin  flakes 4 
27.  Yellow  sandy  clay 5 
26.  G  ray  clay 2 
25.  Gray  sandy  clay 3 
24.  Gray  and  yellow  clay  in  alternating  bands 4 
23.  Brown  clay  shale (i-10 
22.  ( i  ray  clay 5 
21.  Sandy  clay 7 
20.  Gray  clay  shale  with  calcareous,  ferruginous  concretions (j 
19.  Sand,  showing  er<  ss  laminal  ion 18 
18.  Lignite,  130  feet  above  river 2 
17.  Gray  clay  shale;  crumbles  into  thin  flakes 5 
16.  Gray  sand 15 
15.  Lignite 8-10 
14.  G  ray  sandy  clay 30 
13.  Gray  and  yellow  sand,  with  iron  nodules 10 
12.  Yellow  and  gray  clay  shale,  with  iron  nodules 10 
11.   Lignite  with  seams  of  brown  clay 1          6 
10.  Gray  clay  shale;  breaks  into  Hakes 8 
9.  Lignite 2 -3 
8.  Gray  clay  shale 7 
7.  Gray  sand 2 
"0.  Yellow  and  gray  clay  shale,  breaks  into  flakes 2 
5.  Brown  Clay  shale 4 
4.  Lignite 9 
3.  Gray  clay  shale 30 
2.  Lignite 9 
1.  Clay  shale,  to  river  level 15 
451 
In  southeastern  Custer  County,  Mont.,  the  Laramie  formation  is  made  up  very  largely 
'  an  indurated  sandstone  occurring  in  massive  ledges  and  with  a  thickness  of  from  150 
>  300  feet.     Tin,  -ock  is  finely  exposed  along  Big  Box  Elder  Creek,,  where  it  forms  vertical 
