GROUND WATER IN NORTH-CENTRAL TENNESSEE

226 GROUND WATER IN NORTH-CENTRAL TENNESSEE
and that it circulates rather freely. Hence, if the water-bearing beds at
these several places are actually connected, the water-bearing open­
ings probably constitute a system of solution channels that receives
water by percolation from the surface and discharges it into the Cum­
berland Eiver. Such a system might comprise either a few branch­
ing ground-water arteries or many braided small channels. Ground
water might be maintained under artesian head in such a system of
channels by the hydrostatic pressure of water in the Cumberland
Eiver if the openings through which discharge was effected were few
and small or if they were partly clogged by impermeable material
such as silt and clay. It follows, therefore, that the limestone in
che northern part of Wilson County may be rather extensively chan­
neled and water bearing at a depth somewhat greater than that
attained by most wells but generally more than 350 feet above sea
level. Furthermore, the wells of the Louisville & Nashville Kail-
road at Gallatin, Sumner County (Nos. 135 and 136, pp. 204-205),
which tap a water-bearing bed in the Bigby (?) limestone about 320
feet above sea level, may indicate an extension of this channeled zone
toward the north. The static level of the ground water in these wells
is reported to be between 50 and 100 feet below the surface, or 420
to 470 feet above sea level. If, however, the water-bearing beds of
the wells at Lebanon and Watertown, well 328, and Big Spring are
not connected, the artesian head existing in well 328 must be local
and due to obstruction of its water-bearing channel. Unfortunately,
no other deep wells are known to have been drilled in northern Wil­
son County, so that adqeuate data for analyzing the true hydrologic
condition are not obtainable.
Although at least one deep well (No. 327) has been drilled in Wilson
County in search of oil, no satisfactory records of the lithologic
character or water-bearing properties of the deeper strata are avail­
able. It seems probable, however, that potable ground water of
meteoric origin does not circulate in the limestones much lower than
a plane about 300 feet above sea level, and that water-bearing beds
which may occur at greater depth contain only highly concentrated
water of inferior chemical character.
In the hilly country which constitutes the southeastern quadrant
of Wilson County reliable ground-water supplies are generally derived
from perennial springs or from drilled wells that do not extend much
more than 50 feet below the level of the perennial streams. On the
middle and upper slopes of the hills some wells either do not find any
permeable beds, as in well 350, or encounter only highly concentrated
nonpo table brine, as in well 352.
The chemical character of the ground waters of Wilson County
differs greatly. The water that issues from most of the perennial
springs, especially from those of the tubular type, and that which is