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Geology of the Country near Easton, Penn. 237 
contains a great variety of minerals. ae 
ransition Limestone abounds in the vicinity of Easton. 
Ithas a bluish gray colour; splintery fracture; and con-— 
tains veins of hornstone. Hitherto it has not been found to 
in any fossil remains. Its strata are inclined at differ- 
ent ang) m are sometimes curved. 
Caverns d in this formation; an interesting one may 
be seen urham, about nine miles from Easton, and in 
many places this rock presents isolated summits of the 
nassus, about four hundred yards south 
bridge, in the State of New-Jersey. This 
characterized, consisting of quartz, feldsp 
is inclined at an angle of 70°. Diluvial deb 
- 
ial debris surround it 
on every side, and thus its exact junction with the limestone 
cannot be perceived ; but it has the same inclination as that 
rock, and contains a vein of limestone. 
Transition Clay Slate extends from the foot of the Blue 
Mountains, nearly half way across the valley: there isa 
marked difference between the fertility of the farms situa- 
ted on this tract, and those of the transition limestone. 
Slate quarries have been opened on this formation near 
the banks of the De:aware, by a company of proprietors in 
Philadelphia; but the inferiority of the transition slate has 
rendered the shares not very productive. ee, 
Transition Sandstone—this name may be applied to a 
quartzose breccia, of which the Blue Mountains are com- 
Posed in this part of their range. They may be distin- 
Suished at a great distance by the shadowy tint of the for- 
ests by which they are covered, and by the even line with 
which they bound the horizon. Where the Lehigh river 
Passes through the mountain, the breccia exhibits polygo- 
