FORMING THE BAD LANDS OF JUDITH RIVER. 
135 
Vertical Section, Exhibiting a Portion of the Strata of the Great Lignite Basin, near Fort 
Clarke, on Missouri. 
A 
i 
I 30 feet. 
Ferruginous sandy marl, passing downwards into varie¬ 
gated argillaceous grits; contains Paludina Leal, 
P. return , P. Leidyi, P. troehiformis. 
| Fort Union, Yellow Stone, Bed 
Spring, ten miles above Fort Clarke. 
B 
2 inchs’. 
Seam of impure reddish lignite. 
Bed Spring to Fort Union. 
C 
10 to 12 
feet. 
Yellowish gray, friable grit, with numerous argilla¬ 
ceous concretions in horizontal layers, containing 
beautiful impressions of leaves of the genera, Pla- 
tanus, Acer, Ulmus, and Ferns. 
Best developed and mostfossiliferous 
at Bed Spring, ten miles above Fort 
Clarke. It occurs also along the Mis¬ 
souri to Fort Union, where it contains 
fiue impressions of Ferns as well as Di¬ 
cotyledonous leaves. 
D 
3 inchs’. 
Seam of lignite, very much mixed with clay and sand. 
Bed Spring and up the Missouri 
E 
If 
10 feet. 
Yellowish gray grit, very friable, and containing lay¬ 
ers of argillo-calcareous concretions, charged with 
leaves of the same species of plants, as in bed C. 
Bed Spring, &c. 
3 inchs’. 
Seam of earthy lignite. 
Bed Spring, &c. 
Gr 
15 feet. 
Yellow and drab clay and friable sandstone, contain¬ 
ing argillaceous concretions, with impressions of 
leaves like those in beds C. and E. 
Bed Spring to Fort Union. 
ii 
4 inchs’. 
Dark reddish, earthy lignite. 
Bed Spring, &c. 
i 
20 feet. 
15 feet. 
Yellow arenaceous grit, very friable, with some small 
Paludinas , Corbulas, 
Bed Spring. 
j 
Alternations of lignite and cloy. This bed is vari¬ 
able in thickness as well as in the proportions 
of the materials at different localities; contains 
large quantities of fresh water shells. 
Fort Clarke, Bed Spring, and other 
localities along the Missouri. 
K 
40 feet. 
Heavy bedded gray and ferruginous friable sand¬ 
stone, with great numbers of fossils, forming seams 
of shell marl; Melania Ncbrascensis, Paludina 
multilineata, P. peculiaris, Bulimus limnea- 
formis, Corbula mactriformis, with numerous 
impressions of Dicotyledonous leaves in argillo- 
calcareous concretions. 
Very largely developed at Fort 
Clarke, Bed Spring; is also seen 
where the Tertiary beds are exposed 
along Missouri and Yellow Stone. 
L 
M 
2 feet. 
Seam of impure lignite, probably local. 
Bed Spring; not seen at many lo¬ 
calities. 
4 feet. 
Gray argillaceous friable grit, usually passing down¬ 
wards into a dark brown carbonaceous clay. 
Fort Clarke, Bed Spring, and along 
Missouri. 
N 
2 feet. 
Lignite, purest in the section. 
Fort Clarke to Fort Berthold, to 
Fort Union. 
0 
6 feet. 
Very dark carbonaceous clay passing down into very 
bluish gray arenaceous clay, contains at Fort 
Berthold a species of Paludina, also Planorbis 
fragilis, and a few impressions of leaves, petri¬ 
fied wood, &c. 
Fort Clarke, Bed Spring, Fort Ber¬ 
thold and Fort Union. It is also seen 
above Fort Union along the Missouri. 
P 
2 feet. 
Bather pure lignite. This bed is local. 
About 7U miles below Fort Clarke, 
near the point where the Tertiary beds 
first appear in ascending the Mo. 
Q 
40 to GO 
feet. 
Gray compact or somewhat friable concretionary 
sandstone; contains Gy vena Moreauensis, C. in¬ 
ter-media, Thespesius occidentalis, Compsemys 
victus, &c. 
Near Long Lake on the Missouri. 
On Moreau Biverand Cherry Creek. 
