36 ECONOMICAL MINERALOGY. 
In the Counties of Madison, Onondaga, and in some of the still more western ones, there 
not unfrequently occur deposits, to which Mr. Vanuxem has given the name of Tufaceous 
Iron Ore, being a mixture of calcareous tufa and hydrate of iron. Among other localities, 
may be noticed one a mile west of Chittenango in Madison county; another, two and a half 
miles northeast of Salina in Onondaga ; and another on Nine-mile creek, between Marcellus 
and the great embankment of the Syracuse and Auburn railroad. 
The proportion of oxide of iron in this compound is usually small. With the magnetic 
oxide, it would be valuable as a flux ; but it so happens that the abundant iron ore of Western 
New-York, (the lenticular clay iron ore,) is itself largely mixed with carbonate of lane. 
