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Mesozoic and Cenozoic Geology and Paleontology. 5] 
THE CZANOZOIC AGH OR TERTIARY PERIOD. 
By S. A. Mituer, Esq. 
[Continued from Vol. wit., page 288. | 
In 1858, Dr. F. V. Hayden* prepared a vertical section, showing 
the order of superposition of the different beds of the Tertiary Basin 
of White and Niobrara rivers. The Miocene, he divided, in ascending 
order, as follows: 
1. Bed A.—Light gray, fine sand, with more or less calcareous 
matter, passing down into an ash-colored plastic clay, with large 
quantities of quartz grains disseminated through it, sometimes form- 
ing 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 pinkish 
bands. Immense quantities of silex, in the form of seams, all through 
the beds. Titanotherium Bed. Found on Old Woman’s creek, and 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. ‘Thickness, 80 to 100 feet. 
2. Bed B.—A deep flesh-colored, argillo-calcareous, 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 profusion of 
Mammalian and Chelonian remains, Turtle and Oreodon Bed. Found 
on Old Woman’s creek, a fork of Sbhyenne river, on the head of the 
South Fork of the Shyenne; most conspicuous on Sage and Bear 
creeks, and at Ash Grove Spring, and well developed in numerous 
localities in the valley of White river. Thickness, 80 to 100 feet. 
3. Bed C.—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 twenty-seven were counted at one locality, 
from one inch to two feet in thickness. Found on White river, Bear 
creek, Ash Grove Spring and head of Shyenne river, but most con- 
spicuous near White river. Thickness, 50 to 80 feet. 
4. Bed D.—A dull, reddish-brown, indurated grit, with many layers 
of silico-calcareous concretions, sometimes forming a heavy-bedded, 
* Proc. Acad. Nat. Sci., vol. x. 
