QUATERNARY DIVISION. 141 
estuaries, they are more distinct. They are rarely, however, so well characterized as in the 
valleys of the Connecticut, the Thames, and most of the southern and western rivers. 
In Rensselaer county, the sand and clay members of this division are described as alluvion 
by Prof. Eaton ; the clay ranging in a stripe from the south end of the county, nearly parallel 
to the river, and one or two miles wide, and a quarter to half a mile from the river, as far as 
Troy. The sandy deposit lies east of the clay and above it, and one or two miles wide.* 
“ The clay range approaches the river as it proceeds northerly, and forms most of the first 
hill back from the bank of the river, and it continues pretty uniformly throughout the county. 
On the river side of these ranges, the soil is mostly gravelly loam or river alluvion. In some 
places, clay flats are formed. On the eastern side commences the yellow loam, often very 
gravelly, which forms at the least three-fourths of the soil of the county. In some places, it 
contains so much clay as to be denominated clay loam ; in other places, it should be called 
upland loamr\ Remarks nearly similar in regard to some of the members of this forma¬ 
tion, and to the soils, might be applied to all the counties on the Hudson from the High¬ 
lands to Lake Champlain. 
(cZ.) Economical applications. 
The materials forming the different members of the quaternary division are applied very 
extensively to useful purposes. The clays are used to improve the sandy soils, and make 
them more loamy; to the glazing of stone ware; to the manufacture of common earthen 
ware, and of tiles and bricks. The sands are used for casting or moulding sand, sawing 
marble, moulding bricks, for smoothing and rubbing stones used in lithography, blotting sand, 
and for making mortar and glass. Most of the localities of sands used in the arts will be dis¬ 
cussed under the tertiary. The gravel and pebble beds furnish inexhaustible supplies of 
hard, smooth, round stones for paving. The drift and tertiary beds also furnish these, and 
the localities used will be mentioned in another place. The brick manufacture gives employ¬ 
ment to a greater number of individuals, and to more capital, perhaps, than all the others. 
The Albany clay has long been used for glazing stone ware, and is transported to various 
parts of the country for this purpose. Both the buff colored and blue clays are used for 
making bricks. Sand in variable proportions is trodden or ground with the clay, so as to give 
a suitable degree of porosity to the wet brick, that it may not crack in drying or in burning. 
Some of the clay beds contain thin layers of sand, so that the material requires little or none 
to be added, as at Cornwall; others require one-third sand, but the sand beds are never far 
distant, so that the transportation of that material costs little, and very frequently the same 
bank of earth that yields the clay is capped by beds of sand. Some of these sand banks fur¬ 
nish the fine sand used in moulding bricks. A bank of this sand, on the shore of the Hudson, 
is valuable, as it sells for twenty-five cents per bushel. The brick-yards are generally sup- 
Eaton. Geological Survey of Rensselaer County, 1822, p. 25. 
t Ir. pp. 25, 26. 
