OF THE UPPER MISSOURI. 
69 
VERTICAL SECTION OF THE CRETACEOUS FORMATIONS OF NEBRASKA TERRITORY, SO FAR AS DETERMINED. 
SuBDIVISIONS. 
LocauirigEs. 
Estimated 
thickness 
No. 5. 
Gray and yellowish arenaceous clays and sand- 
stones at many localities, very ferruginous, with 
numerous concretions and a profusion of molluscous 
fossils, as Belemnitella bulbosa, Nautilus Dekay?, 
Ammonites placenta, A. lobatus, Scaphites Con- 
radi, Baculites ovatus, Ostrea subtrigonalis, and 
a great number of marine mollusca. 
All around the Black hills and head 
waters of the Shyenne, Moreau trading 
post, and under the Tertiary at Sage and 
Bear creeks; at the head of Teton river 
and at Long lake on the Missouri. 
100 to 150 feet. 
No. 4. 
Bluish and dark gray plastic clays, containing 
Nautilus Dekayi, Ammonites placenta, A. Halli, 
Baculites ovatus, B. compressus, with numerous 
remains of Mosasaurus. 
Along the Missouri river, below Fort Pierre, there 
is a local bed at the base of No. 4, composed of 
dark, very unctuous clay, containing much car- 
bonaceous matter, with veins and seams of selen- 
ite, sulphuret of iron, and fish scales. 20 feet. 
other marine mollusca, 
Around the Black hills; a great area 
around Fort Pierre, and along the Mis- 
souri. Under No. 5 at Sage and Bear 
creeks, along the Shyenne at Great Bend; 
on the Yellowstone and near Milk and 
Musselshell river. 
350 feet. 
No. 3. 
| 100 feet. 
30 feet. 
Lead gray calcareous marl weathering above to 
a yellowish tint; scales and other remains of fishes ; 
Ostrea congesta, passing downwards into 
Light gray yellowish limestone, containing great 
numbers of noceramus problematicus, Ostrea con- 
gesta, and fish scales. 
In the valley of Old Woman’s creek ; 
at Bear peak; around the Black hills and 
the sources of the Shyenne ; in the bluffs 
along the Missouri, from Big Sioux river 
to Great Bend. 
150 feet. 
a 
No. 
No. 1. 
Dark gray laminated clay, with teeth and scales 
of fishes, Ammonites alpinianus, A. percurinatus, 
Serpula tenuicarinata, Inoceramus problematicus, 
a smail oyster like O. congesta, Xe. 
Old Woman’s creek; Black hills; 
along the Missouri river from ten miles 
above James river to Big Sioux river. 
200 feet. 
Yellowish and reddish friable sandstone, with 
alternations of dark and whitish clays. Seams and 
beds of impure lignite, fossil wood, impressions of 
dicotyledonous leaves; olen, Pectunculus, Cy- 
prina, &c. Lower Cretaceous. 
Old Woman’s creek ; Black hills ; near 
the mouth of Big Sioux river; Lower 
Platte; near Judith river. 
100 to 200 feet. 
