LIVINGSTON COUNTY. 
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becomes a thick one at a few rods distance. Sometimes the courses are separated by a thin 
irregular course of hornstone; at others, this hornstone is in the centre or near the surface of 
a layer of limestone. 
From Christie’s quarry the limestone pursues a northwesterly direction, passing just to the 
south of Caledonia village ; it crosses the road a little west of that place, and pursues the same 
direction to the top of the terrace on the south side of Allen’s creek. West and northwest 
of Caledonia, large numbers of fossils are found in this rock. In this part of the town, the 
lowest portion of the rock is thick-bedded and compact; above this it contains a large pro¬ 
portion of hornstone, and in some places is composed almost entirely of that substance. Being 
in irregular shaped masses, and surrounded by limestone, which decomposes on exposure, it 
is left scattered over the surface in rough and shapeless forms. These fragments are crossed 
in every direction by innumerable fissures, which are expanded by freezing water, and the 
whole falls into small fragments, which, in many places, literally cover the surface for many 
acres. Where the road crosses this part of the rock, it has the appearance of being made in 
a bed of flints. 
From the jagged and irregular appearance of the hornstone rock, as it occurs in detached 
masses, it has received the familiar and expressive name of “ chawed rocli .” This rock is 
the best material for road-making which Western New-York affords. Where it approaches 
the surface the soil is rather barren, producing only a growth of dwarf oaks ; but where there 
is a tolerable proportion of finer materials, it produces a fertile soil. A large proportion of the 
native growth along this terrace consists of oaks. 
Marcellus Shales. —The limestone is succeeded by the “ Marcellus shales.” These shales 
possess their usual essential characters ; the middle portions quite compact and highly bitumi¬ 
nous, becoming more slaty above and below. The compact part of the shale usually contains 
large septaria; these sometimes consist of large silico-calcareous masses, without seams of 
crystalline matter. This rock follows the same course as the limestone : commencing on the 
east near the north line of the county, it passes southwest to the Genesee river; thence its 
course is northwest through Caledonia, passing into Genesee county near the north line of this 
town. 
On the Conesus outlet, near the lower saw-mill at Avon, this shale may be seen resting on 
the limestone. About thirty-five feet from the bottom of the shale there is a stratum of lime¬ 
stone one foot thick, sometimes concretionary, and containing Orthoceras, fragments of trilo- 
bites, etc. For several feet below this, the rock is black, slaty and very fragile. A few feet 
of the shale above this limestone is black and slaty ; it abounds in fossils of Orthoceras , 
Orthis, Stropliomena , Avicula, and a very small species of Orbicula. Above this the mass 
graduates into a greyish or bluish grey slaty shale, and contains few fossils. 
This shale is seen in the ravines and hill-sides on the west side of the Genesee, extending 
through the northeast corner of York, and thence through the southwest part of Caledonia. 
At one place in the south part of this town, a digging for coal has been made in the black 
shale. The indications which induced the undertaking at this place were the black and highly 
