406 WEED AND PIRSSON 
Cambrian shales are well exposed above the town, and the dark 
gray, shaly, Jurassic limestones form the foot slopes near the 
settlement. 
Cambrian.—A half mile above Landusky the west bank of 
Mill Creek shows exposures of 75 to 100 feet of quartzite resting 
upon the main porphyry mass, which has been intruded between 
the Cambrian quartzite and the Archzxan nucleus of the hills. 
Above the quartzite are greenish gray shales of which no good 
exposures were seen, probably 200 feet thick and succeeded by 
sage-green shales carrying poorly consolidated conglomerates 
and lenses of glauconitic limestone two inches thick and of 
varying size. The shale is evidently somewhat calcareous and 
micaceous, and shows fucoid rolls. The exposure is but 150 
feet long, and the shaly series is overlain by thinly bedded 
limestones. The following section was made at the locality: 
No. Feet 
6 25 Thinly bedded and fissile limestones. Pure limestones 
with shell remains, alternating with impure, sandy, and 
more or less conglomeratic beds, the general color 
being gray. 
5 do Limestone conglomerates and gray shales; greenish 
sandy layers alternating with purer argillaceous beds. 
A few thin beds of limestone occur from which a few 
fossils were taken. 
4 50 Green shale beds, carrying limestones and conglomerates. 
3 30 Green or copperas-colored shales. 
2 300? Interval in which the beds are not exposed. 
I 75 Quartzite, changing to conglomerate near the base; gen- 
erally flesh colored; mostly brecciated and rusty. 
These rocks dip at an angle of 40° toward the town, the 
strike being N. 60° W. The conglomerates of this section are 
clearly formed of beach shingle, as the pebbles are all flat. 
The rocks are very loosely cemented and easily disintegrable, 
which accounts for the rarity of exposures of these beds through- 
out the mountains. The impure sandstones interbedded with 
the shales consist of rounded quartz grains with a green coating 
or shell of glauconite. 
The fossils from the limestones forming part of No. 5 of this 
