472 GEOLOGY AND MINERALOGY. 
land occur upon this formation in Hastings County. Themore rocky portions also, 
if useless in other respects, will probably constitute available grazing landés, as 
the country becomes gradually cleared. 
2, The Lower Silurian Formation :—This formation is sub-divided from the 
upper part downwards, into the following subordinate groups: 
5. The Hudson River Group. 
4. The Utica Slate. 
The Trenton Limestone. 
The Black River Limestone. 
The Bird’s-eye Limestone. 
The Chazy Limestone. 
8. The Trenton Group. 
2. The Calciferous Sand Rock. 
1. The Potsdam Sandstone. 
In Hastings County, the three lower members of the formation are alone 
present; and of these, the Potsdam Sandstone and Calciferous sand-rock are more 
or less blended together, and are also but slightly developed. Their common 
representative appears to be a calcareous sandstone of a few feet in thickness, 
occurring immediately above the Laurentian rocks, or at the extreme base of the 
Silurian formation. This sandstone is of a light greenish colour above, passing 
into pale red, or pale red with irregular greenish spots below. It may be seen in 
horizontal position, or dipping almost imperceptibly toward the south-west, on the 
river banks at the village of Marmora, and also on the banks of the river Moira at 
Tweed village, in Hungerford township, as well as at other places near the outerop of 
the Laurentian rocks. It is apparently destitute of fossils. The succeeding 
Trenton group, properly so called, is, on the other hand, largely developed, and 
constitutes the foundation rock of the whole of the South Riding of the County, and 
also of the southern portion of the North Riding. At its base in the North Riding 
a band of fine grey limestone, available as a lithographic stone, is met with, This 
is succeeded by (in general) a thick-bedded limestone, poor in fossils; and the 
latter is again followed, in ascending order, by thin-bedded and shaly lime- 
stones, containing fossils in very great abundance. A list of these fossils 
comprising various corals, brachiopods, &e., collected around Belleville, may be 
geen ina paper by the writer, published in the Canadian Journal for January, 
1860, [New Series, vol. V.] The Trenton limestone is well displayed along the 
banks of the Trent, Moira, and Salmon Rivers, and in many places on the shores 
of the Bay of Quinté. It yields excellent lime; and building stones of good 
quality are obtained from some of the thick beds, as at Ox Point, near Belleville, 
and elsewhere. Some care, however, is required in their selection, as many of 
them are apt to crack from minute flaws; but properly selected blocks appear to 
resist the action of frost remarkably well. 
3. The Drift Formation :—An accumulation of clay, sand, and gravel, with 
rounded stones or “ boulders,” partly of limestone, but chiefly of the more north- 
ern gneissoid rocks, is spread over the surface of the greater part of the County. . 
The same deposit extends indeed over the larger portion of the Province itself, 
and reaches far into the United States. Geologically, it isiknown as the Drift, or 
Drift and Boulder formation. Its age is much more recent than that of the under- 
