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a pure siliceous sand. This loam contains abundance of fine particles 
of limestone, and when burned becomes lime; the action of water on 
such bricks is rapidly destructive. The bricks made near Lockport are 
of this character. 
On the lake shore a bed of clay continues almost from the eastern to 
the western extremity of the county. In some places this bed thins 
out, and its place is supplied with gravel or loam, and sometimes the 
clay is intermixed with one or both these substances; the upper part is 
gray and less pure than the lower. The lower part usually is of a blu- 
ish colour, which sometimes extends throughout. This blue clay is fre- 
quently variegated with spots of brown and green. Where the lower 
part of the stratum is seen, it rests on a partially indurated deposit of 
gravel and clay, of a reddish colour, and this rests on the red marl or 
sandstone. The clay is from two to six feet thick, and often contains 
pebbles and boulders, similar to those on the lake shore. Frequently we 
observe alternations of the clay and a part of the gTavel stratum below 
and above, and the clay is often much bent and contorted, although it 
rests on a nearly horizontal base. These alternations and contortions 
are in many places very remarkable, and would induce the belief that 
almost any position, observed in stratified rocks, may be given during 
their deposition. The presence of pebbles and boulders in the clay, 
proves that the water from which it was deposited had suflScient velo- 
city to transport large and heavy materials. 
The gray loamy clay above the blue clay sometimes attains the 
thickness of four or five feet, and in some places occupies the place of 
the blue clay, where this has apparently been removed. The gray, 
where it occurs, is entirely distinct from the blue, and appears as if it 
might have been deposited at a subsequent period. In this clay we 
find the calcareous concretions called clay stones, or " clay dogs;" these 
substances assume all imaginary forms, sometimes the most fantastic. 
They are often in the shape of spheres, and sometimes two or more of 
them attached together. They appear at regular intervals in the strata, 
and commonly a line of them marks the junction of the gray with the 
blue clay below. These substances are an earthy carbonate of lime, 
which is apparently deposited from the water percolating from the sur- 
face. Fibres (apparently vegetable) extend from the surface to the 
depth of three or four (sometimes twelve) feet, and around these fibres, 
as a nucleus, the deposit is made. The gray loamy clay is pervious to 
water, while the blue clay is not. The fibres never extend into the 
