466 
GEOLOGY OF THE FOURTH DISTRICT. 
at Morgansville, where the Black creek descends from the limestone terrace to the level of the 
country north. The section at this place is given on page 140 of this report. 
This rock forms the northern escarpment of the great limestone terrace, extending from the 
Genesee to Lake Erie, and is also seen in the counties east. It passes through the towns of 
Leroy, Stafford, Batavia, and the south part of Alabama, forming the lower falls on the 
Indian reservation. I am not aware that it has been used for cement in this county, though 
it is doubtless good for this purpose. 
The Onondaga and Corniferous limestones occupy the summit of the terrace; extending 
from Livingston county westward ; pass with variable width to the north of the village of Leroy; 
underlying Stafford, Morganville, ihe north part of Batavia and Pembroke. A few feet of the 
lower portion of these rocks is in regular courses, with little or no hornstone ; the succeeding 
forty or fifty feet consists principally of hornstone, being a rough ragged mass, called the 
u chawed rock." This, in some places, contains large numbers of corals. 
About two and a half miles north of the village of Leroy, and west of the creek, there! s 
an extensive quarry in the Onondaga limestone. The rock at this place appears in courses, 
varying from six inches to two feet; it is almost wholly composed of fragments of Crinoidea and 
other fossils, crystalline in texture, quite tough. The thick courses are often divided by seams : 
these, when of clay, cause the blocks to separate ; at other times they produce no injury. 
From the quarry, the rock is taken to a mill a mile south of the village, and sawn into slabs 
and blocks ; it is afterwards polished and used for fire places, mantle pieces, etc. The 
polished stone has often a very beautiful appearance, and is highly prized by the collector, 
on account of displaying the internal structure of fossils cut through in the process. The 
crinoidal joints are frequently of a different color from the surrounding mass, a variety which 
increases the beauty of the stone. 
Lime is burned at many points along this range, supplying the immediate neighborhood, 
and also the country north and south. In Stafford, Batavia and Pembroke, this rock appears 
in numerous localities. Two and a half miles from Batavia village, and half a mile from the 
north line of the town, the rock exposed is the hydraulic limestone, with some thin layers 
above, and the greater part consisting of the “ chawed rock." This latter is most annoying 
to the farmer, and when it overspreads the surface in large masses, almost totally forbids 
cultivation. This is seen in several places of small extent, in the south part of Alabama. 
The growth of timber on such land consists chiefly of oak. 
On the Indian reservation, this rock appears at the upper falls, and in the stream below ; 
also between this and Pembroke. The thickness of the mass is very variable, as may be 
seen in the quarries, where thick masses at one place may be merely recognized in another 
by layers of a few inches. West of Batavia the terrace is not so well defined, though there 
is little difficulty in tracing the course of the limestone. 
The shales above the limestone are seen to less advantage in the county of Genesee than 
in any other of the same range. At Leroy the Marcellus shale succeeds the limestone, and 
is well exposed in the bed of the stream at that village It contains large masses of septaria, 
