150 
PROCEEDINGS OF THE ACADEMY OP 
Subdivisions. 
Localities. 
A deep flesh colored argillo-cal- 
careous indurated grit ; the outside 
when weathered, has the appearance 
of a plastic clay. Passes down into a 
gray clay, with layers of sandstone ; 
underlaid by a flesh colored argillo- 
calcareous stratum, containing a pro- 
fusion of Mammalian and Chelonian 
remains. Turtle and Oreodon Bed. 
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 
Grrove Spring. Well de- 
veloped in numerous local- 
ities in the valley of White 
river. 
pq 
Light gray fine sand, with more or 
less calcareous matter, passing down 
into an ash-colored plastic clay, with 
large quantities of quartz grains dis- 
seminated through it, sometimes 
forming aggregated masses like 
quartzose sandstone cemented with 
plaster ; then an ash-colored clay 
with a greenish tinge, underlaid at 
base by a light gray and ferruginous 
silicious sand and gravel, with pink- 
ish bands. Immense quantities of 
silex in the form of seams all through 
the beds. Titanotherium Bed. 
Old Woman's creek ; also 
in many localities along the 
valley of the South Fork of 
Shyenne. Best development 
on Sage and Bear creeks. 
Seen at several localities in 
the valley of White river. 
Cretaceous beds 5 and 4, with their 
usual lithological characters and fos- 
sils. 
Exposed underneath the 
Tertiary Beds on the South 
Fork of Shyenne and its 
Southern Branches, also in 
White river valley near its 
source. 
By reference to the map it will be seen that our route, which is indicated by 
a dotted line, led us up the Loup Fork of the Platte river to its source, thence 
a little west of North to the Niobrara river, and up the latter river to Fort 
Laramie. From Fort Laramie we proceeded nearly north to the Black Hills, 
and, on our return, crossed the Shyenne and White rivers, striking the Niobrara 
again above the mouth of Little Rapid river. We then passed down the Niobrara 
to its entrance into the Missouri river. Inasmuch as the surface deposit ot 
the greater portion of the country thus passed over, is composed of the different 
beds of the Tertiary basin of which I am now treating. I think I can show more 
clearly the geographical area of this formation and that of its subdivisions, 
also the changes in the lithological characters, by giving- a brief digest of my 
journal as we proceeded from point to point. 
Ascending the Loup Fork, the first indication we observed of this formation 
was near the old Pawnee village, about eight miles above the mouth of Beaver 
creek. Here we found, near the bed of the river, large masses of pebbly con- 
glomerate, cemented with a calcareous grit, which undoubtedly belongs to bed 
[June. 
