104 
GEOLOGY OF THE FIRST DISTRICT. 
Gaseous and Thermal Springs. 
Those gaseous springs that contain large quantities of mineral matter in solution, have been 
considered under the heads of chalybeate, hepatic and acidulous springs. There is still another 
class in which the mineral qualities of the water are not striking, but the water contains gas 
which is continually bubbling up from the bottom of the fountain, and which, in the First 
Geological District, is mostly nitrogen, mixed in some instances with some carbonic acid 
and oxygen. A considerable number of these springs have been observed, and some of 
them during the progress of the geological survey. Their geological situation is on or near 
the junction of limestone with a talcy slate, which is considered as an altered rock ; and both 
these rocks may, in many places, be considered metamorphic. They are all adjacent to faults 
in the strata, or where the rocks are much deranged in position. Some of the springs are 
thermal, and perhaps all of them would prove to be so by a careful measurement of their 
temperatures. Some of them deposit tufa, but most of them are as pure as common spring 
water, and are employed for domestic uses. Professor Eaton states that the springs through 
which nitrogen gas rises, contain muriate of lime in solution.* 
The range of these springs, as far as has been observed in the eastern part of the State of 
New-York, is from near the Vermont line in the township of Hoosick, Rensselaer county, by- 
Lebanon Springs, to near Stony point in Rockland county. Those of Virginia, and perhaps 
intermediate ones, (if I have correctly understood the Geologists of Virginia and Pennsylva¬ 
nia, Professors W. B. & H. D. Rodgers,) may be considered as on the same great axis of 
disturbance. It is probable that observers may find similar springs in Vermont, Massachusetts 
and New-York, along the continuation of this line of disturbance, which is near the line be¬ 
tween New-York, Massachusetts and Vermont, with a breadth of several miles (including the 
east part of several counties in New-York), as far as Poultney and Hampton, whence it ex¬ 
tends into Vermont. The thermal springs at Bath, Virginia, and still farther south, have 
nearly the same geological relations as those of New-York, and are on the same or parallel 
axes of upheaving action. 
Hoosick Gaseous Springs. 
These springs are numerous in an area of about one hundred acres. They rise through 
the gravel beds of the drift deposits. No rock in place was seen in the immediate vicinity, 
but the roof slate stratum ranges west of them within a mile, and this rock is believed to be 
uniformly skirted at a distance of one to two miles on the east by a stratum of limestone ; 
and it is probable that the rock, at some depth below the soil at these springs, is limestone of 
the character of that at Lebanon springs.! The flow of water is copious, and the gas rises in 
abundance. It is mostly nitrogen, as has been shown by Professors Lewis C. Beck and Amos 
* Eaton. Geological Survey of Rensselaer county, p. 30. 
t Prof. Eaton long ago supposed these springs to be derived from the limestone. (Vide Silliman’s Journal, X V. p. 234.) 
