PRrossEeR.|  Cretaceous.—Comanche Series of Kansas. 125 
indicated. Down the ravine below the prominent exposure of 
Cheyenne sandstone, just described, is shown the contact of the 
Cheyenne and Red beds. In this ravine the rocks composing the 
upper part of the Red beds are a very bright red color and beautifully 
exposed. The upper part of the red shales near the contact consist of 
24 feet of variegated red and yellow colors, then 3 feet of yellowish- 
gray argillaceous shales in texture similar to the shales below, and 
above these the coarse-grained sandstone of the Cheyenne. The 
latter is variously colored although the prevailing one is white to 
vellowish-white; and is very irregularly bedded, exhibiting excel- 
lent examples of cross-bedding. The Cheyenne sandstone at first 
consists of fine clear quartz sand in which are frequently small 
pebbles. It is probable that during the sedimentation of the Red- 
seds in an inland sea there was a period of great quiet with steady 
deposition of sandstones, shales and gypsum in brackish water; 
then came a series of oscillations as shown by the coarse and irreg- 
ular deposits of the Cheyenne, changing the inland sea of the Reds 
to the marine sea of the Kiowa which contains thin, even, shales and 
caleareous rocks with an abundant marine molluscan fauna. The 
section of this small ravine is as follows: 
No. Feet. 
4. On top coarse-grained very irregularly bedded 
Cheyenne sandstone. 
3. Gray to greenish-yellow argillaceous shale which in 3 —45%$ 
the upper part contains very fine grains of quartz 
sand. 
2. Red and yellowish shales, transitional from the 24—424 
gray Cheyenne sandstone to the bright red shales 
of the Red-Beds. 
Ppacedushales;andusamd Stones yas salen nie ius aaa 40 —40 
In a rayine to the southeast of Hell’s Half Acre there is an ex- 
cellent exposure of the contact between the Cheyenne sandstone and 
ihe Red-beds showing clearly a line of unconformity between these 
two formations, indicating a pre-Cheyenne erosion of the Red-beds. 
It also shows conclusively that at the top of the Red-beds there are 
variegated shales from 2 to 3 feet in thickness, then 3 feet of sandy 
light gray to yellowish shales, above which is the coarse irregularly 
