OF THE UPPER MISSOURI. 
VERTICAL SECTION, continued. 
105 
SuBDIVISIONS. 
PLIOCENE TERTIARY. 
Bed F. 
Ist. Dark gray or brown sand, loose, incoherent, 
with remains of mastodon, elephant, &c. 2d. Sand 
and gravel, incoherent. 3d. Yellowish white grit, 
with many calcareous, arenaceous coneretions. 4th. 
Gray sand with a greenish tinge; contains the 
greater part of the organic remains. 5th. Deep 
yellowish red arenaceous marl. 6th. Yellowish 
gray grit, sometimes quite calcareous, with nume- 
rous layers of concretionary limestone from two to 
six inches in thickness, containing freshwater and 
land-shells, Succinea, Limnea, Paludina, Helix, 
&c., perhaps all identical with living species; also 
much wood of coniferous character. 
LOCALITIES. 
Covers a very large area on Loup fork, 
from the mouth of North branch to 
source of Loup fork; also in the Platte 
valley. Most fully developed on the 
Niobrara river, extending from the mouth 
of Turtle river three hundred miles up 
the Niobrara. Also on Bijoux hills and 
Medicine hills. Thinly sgceneriont in 
the valley of White river. In iso 
patches over a large portion of abe 
territory, west of the Coteau de Prairie. 
Bed E. 
| incoherent ; 
Usually a coarse-grained sandstone, sometimes 
heavy-bedded and compact; sometimes loose and 
varies much in different localities. 
Forms immense masses of conglomerate ; also con- 
tains layers of tabular limestone with indistinct 
organic remains; very few mammalian remains 
detected, and those in a fragmentary condition. 
Passes gradually into the bed below. 
Most fully developed along the upper 
portion of Niobrara river and in the re- 
gion around Fort Laramie. Seen also on 
White river and on Grindstone hills. 
MIOCENE. 
Bed D. 
Bed C. 
A dull reddish brown indurated grit, with many 
layers of silico-caleareous concretions, sometimes | 
forming a heavy-bedded fine-grained sandstone ; 
contains comparatively few organic remains. 
Very fine yellow calcareous sand, not differing 
very materially from bed D, with numerous layers 
of concretions and rarely organic remains, passing 
down into a variegated bed, consisting of alternate 
layers of dark brown clay and light gray calcareous 
grit, forming bands, of which T counted twenty- 
seven at one locality, varying from one inch to two 
feet in thickness. 
‘Turtle and Oreodon 
Bed B 
| 
-| pearance of a plastic clay. Passes down into a 
A deep flesh-colored argillo-caleareous indurated 
grit; the outside, when weathered, has the ap- 
gray clay, with layers of sandstone ; underlaid bya 
flesh-colored argillo-caleareous stratum, containing 
a profusion of mammalian and chelonian remains. 
Turtle and Oreodon Bed. 
< 
=) 
= 
x11.—14 
Niobrara and Platte rivers; well deve- 
loped in the region of Fort Laramie ; also 
in the valley of White river. Conspicu- 
ous, and composing the main part of the 
dividing ridge between White and Nio- 
brara rivers. Also in Green river valley. 
White river, Bear creek, Ash Grove 
spring, head of Shyenne river. Most 
conspicuous near White river. Near the 
eastern base of the Black hills. 
180 to 200 feet. 
a alee pr 
Old Woman’s creek, a fork of Shyenne 
river; also on the head of the South fork 
of the Shyenne; most conspicuous on 
Sage and Bear creeks, and at Ash Grove 
spring. Well developed in numerous lo- 
ealities in the valley of White river. 
Estimated 
thickness 
300 to 400 feet. 
350 to 400 feet. 
50 to 80 feet. 
80 to 100 feet. 
