PROSSER. | Cretaceous.—The Dakota Sandstone. 183 
“Mhe sandstone of the Mentor beds occurs in thin, local strata. 
While these are of slight consequence judged by the space they 
occupy, they are nevertheless of great stratigraphic importance, 
since it is from these alone that our knowledge of the geological 
age of the Mentor terrane has been derived.’ 
DISTRIBUTION. 
Vhe typical locality, as already stated, is the one in the hills east 
ot Mentor and the Smoky Hill river in Saline county. Beginning 
three fourths of a mile east of the Berwick schoolhouse, or three and 
a fourth miles east of Mentor, loose, irregularly-shaped blocks of 
the dark brown very fossiliferous sandstone occur along the east 
and west highway, and in the adjoining fields where sections 16, 
21, 22 and 15 of Walnut township corner. As shown on the Berwick 
diagrammatic section, the first of the Mentor occurs about 60 feet 
above the river level and continues along the road until an altitude 
70 feet higher is reached. As the blocks are not in place, the writer 
dces not intend to say that the sandstone containing the Mentor 
fossils has a thickness of 70 feet at this locality, though he is of the 
opinion that a stratum of the fossil-bearing sandstone occurs not 
far from where it was first noted in the highway. 
Two miles directly south of the Berwick Hill locality just de- 
scribed, the Mentor fossiliferous sandstone occurs, above a thin 
ledge of the Kiowa shales, along the north and south highway at 
the S. W. Cor. Sec. 27, Walnut township. At this locality the Men- 
tor is from 150 to 160 feet above the level of the Smoky Hill river. 
On the hills 2 miles north of the Saline river or 5 miles north 
of the eastern side of Salina, on the western side of a draw in the 
Ss. W. Quar. Sec. 18, Cambria township, is an interesting occurrence 
of the Mentor sandstone which, as usual, is in loose blocks, some 
of them quite large. The rock is of brownish-red color containing 
numerous specimens of fossils although fewer species than were 
found in some of the other Mentor exposures. Below are yellowish- 
gray to buff shales and buff, friable sandstone, while higher is 
brownish, unfossiliferous sandstone. The Mentor stratum is be- 
tween 90 and 100 feet above the level of the Saline river and not much 
1 American Geologist, Vol. XVI, Sept. 1895, pp. 162, 163. 
