226 
GEOLOGY OF THE THIRD DISTRICT. 
Where deposits of alluvial materials exist which contain limestone pebbles, the water which 
passes through them will deposit tufa at its egress, unless too rapidly carried off, and united 
to larger bodies of water from sources of a different kind. Small deposits of tufa from sources 
of the kind have frequently been found in the southern counties, and used for lime. Nume¬ 
rous other deposits will yet be discovered, when under drainage will generally be practised; 
for accumulations of the kind must be found in many low and marshy situations in the sou¬ 
thern counties, from the great abundance of northern alluvial containing pebbles, etc. of 
limestone, which there exists. 
Calcareous Tufa. 
This product without doubt commenced with the first exudations into the valleys when 
freed from water, and has continued to form unto this day. It is an exceedingly abundant 
product, its localities being very numerous, and the quantity prodigiously great at some of 
them. It differs from marl as before mentioned ; the latter having separated from its solvent, 
in water, by which its parts were kept separate, and finally subsided or precipitated; whilst 
the tufa, on the contrary, separated where air had access, or its solvent could gradually escape, 
by which its particles were enabled to cohere and form a solid substance. 
One of its most abundant sources has been the calcareous portions of the gypseous deposit; 
the mass being permeable to water, this fluid deposits the tufa after passing through the mass, 
and appearing again at the surface of the earth. The deposits generally appear at the sides 
of the hills or valleys near the point where the calcareous waters issue, and continue down in 
many instances to a considerable distance, should their course be oblique, or above the drains 
of the valley, else they are arrested by the waters of the valley. Sometimes where the 
deposit has been rapid, a mixture of the earth or marl and the tufa takes place; as on Lime¬ 
stone creek, to the south of Delphi; at the hill back of Brothertown in Oriskany valley, etc. 
The first deposit of note to the east, is north of Cherry-Valley, on the farm of Mr. Schism, 
not far below the falls at Judd’s mill; large masses appear upon the surface over an acre or 
more of ground, on the east side of the creek. 
A curious deposit, from its cavernous nature, exists in the ravine below the new mill north 
of Vanhornsville. 
A deposit appears on the creek about three miles south of Fort-Plain. 
A considerable mass exists on the farm of Judge Loomis, west of Little-Falls, by the road¬ 
side. It is a deposit from a copious spring, issuing from the alluvial hill which skirts the north 
side of the river. The Judge has commenced using it upon his land, and is well satisfied 
with the result, though but the first year of trial. 
Tufa appears in all the creeks along the south of the Mohawk through Herkimer county; 
the largest deposits noticed were near Fish’s distillery, and Myers creek above the furnace, 
the latter a very solid one, and is used at the furnace, and is burnt into lime. 
In Oneida county, it shields large portions of the hill-sides of Oriskany valley, immense 
deposits existing on both sides, but more exposed on the east side below Ely’s sawmill, covering 
