20 
ON THE GEOLOGY AND NATURAL HISTORY 
variety of fantastic shapes, such as domes, towers, and spires, one of which seems to be 
twenty or thirty feet high, but not more than four or five feet in diameter at its base. 
From this pillar the little tributary of the Shyenne derives its name. Very little timber 
is. seen along our route excepting a few scattered pines among the hills. 
On the north side of Old Woman’s branch is a high ridge ranging northwest and south¬ 
east, composed of a variegated sandstone varying in structure from a compact fine silicious 
rock, to a coarse reddish conglomerate or sandstone, with no fossils but indistinct traces of 
vegetable remains. This ridge is the result of a gentle upheaval and is exposed by the 
erosion of the more yielding Tertiary beds from the valley. On the distant hills on each 
side of the valley the naked Tertiary beds are visible, while near the bed of the stream 
the Titanotherium bed is found with its usual lithological characters and containing bones 
and teeth of the animal from which it derives its name. The following section of the 
strata in descending series will show the details of this upheaval: 
1. Layers of white oolitic limestone, doubtless Tertiary. 
2. Compact ferruginous sandstone. 80 feet. 
3. Yellow friable sandstone. 2 feet. 
4. Light gray fine clay. 4 feet. 
5. Yellowish white sandstone, quite friable. 5 feet. 
6. Drab or ash colored indurated clay passing down into red clay. 6 feet. 
7. Variable incoherent clays, red, yellowish, &c , which may be of Jurassic age. 50 feet. 
Passing down the valley of the Shyenne, the Tertiary beds disappear and the Creta¬ 
ceous formation No. 5 occupies the country. At one locality an upheaval was observed 
exposing all the subdivisions of the Cretaceous rocks, as will appear from the following- 
section : 
No. 5. Presenting its usual lithological characters with numerous fossils; strata but slightly disturbed. 100 to 150 feet. 
No. 4. Presenting the same characters as on the Missouri river. 100 feet. 
No. 3. “ “ “ “ “ “ 150 feet. 
No. 2. “ “ “ “ “ “ 200 feet. 
No. 1. “ “ “ “ “ “ 250 to 300 feet. 
No. 5 is but slightly disturbed as will be seen by examining the illustrative section. 
Nos. 4, 3, and 2, present only their vertical edges of their strata across which the above 
measurements were taken. The strata of No. 1 seems to have been elevated so as to re¬ 
tain a nearly horizontal position. No. 3 at this locality contains numerous fossils, the 
most abundant of which are Ostrea congest a, and Inoceram us problematic us. This bed does 
not present altogether the same lithological character as on the Missouri river, but pos- 
