The alluvium forms terraces and floodplains along the Cumberland River
Most wells in the alluvium are inadequate for a domestic supply.
Girkin Formation (Reelsville Limestone, Sample Sandstone, Beaver Bend
and Paoli Limestone) (Mcl)
The Girkin is at the top of Pilot Knob, very localized in extent in
Near outcrop areas, yields from the Girkin are generally inadequate
during dry periods.
Ste. Genevieve Limestone Member of the Monteagle Limestone (Mgl)
This limestone underlies rolling and dissected karst areas.
The limestone yields more than 50 gallons per minute to wells from large
solution openings in karst areas. Most wells penetrate solution openings,
but in areas high above perennial streams these solution openings are
dry in late summer and fall, and many wells are inadequate. Wells that
do not intersect karst conduits generally are inadequate for domestic
use. Springs having low flows ranging from less than 10 gallons per
minute to more than 200 gallons per minute occur at or near stream level
or near the contact with the underlying St. Louis Limestone.
St. Louis Limestone (Mgl)
The St. Louis underlies rolling karst areas. It commonly has less relief
than karst in areas underlain by the Ste. Genevieve Limestone. Resistant
siltstone alternates with nonresistant shale layers to form discontinuous
minor benches on hillsides.
The St. Louis yields more than 50 gallons per minute to wells from large openings
in karst areas. Most wells penetrate some solution openings, but where
openings are small or high above perennial streams, yields are often
inadequate for domestic supply. Yields of wells close to major streams
are large where solution openings are penetrated, but otherwise inadequate.
A major spring horizon occurs near the top of the formation in the karst
areas. Many seepage springs occur throughout the formation; low flows
range from less than 10 gallons per minute to more than 1,000 gallons per minute. The lower
part of the formation is composed of siltstone and argillaceous limestone.
Yields from these sedimentary rocks are low and generally are not adequate
for a domestic supply.
Salem and Warsaw Formations (Msh)
These formations underlie gentle to dissected rolling uplands. They
form steep bluffs where the limestone overlies rocks of Osagean age
and along Lake Cumberland. In some areas, numerous small sinkholes occur
in the formation.
These formations yield enough water for a domestic supply where they
are dominantly limestone and close to perennial stream level. Yields
are low where siltstone or argillaceous limestone is penetrated. A minor
spring horizon occurs at the contact of the limestone with the underlying
siltstone or argillaceous limestone. Another spring horizon occurs near
the contact of the Warsaw and Fort Payne. Low flows generally are less
than 5 gallons per minute.
Fort Payne Formation (Mbf), limestone bodies within Fort Payne (ls)
The Fort Payne underlies dissected rolling uplands, and forms steep
valley sides in maturely dissected topography. Small valleys are steep
and V-shaped. Siltstone and chert form discontinuous ledges on hillsides.
Wells in lowland areas close to streams produce enough water for a domestic
supply and may produce more than 5 gallons per minute from solution
openings. Most wells obtain water from perched or semiperched water
bodies supported by discontinuous shale layers, and many are dry during
late summer and fall. Minor spring horizons occur throughout the formation.
Flows are as much as 30 gallons per minute, but most go dry in late
summer or fall. Where shale layers are conspicuous, most wells are inadequate
for domestic use. Where chert layers are thick and extensive in area,
yields of more than 5 gallons per minute may be obtained.
Chattanooga Shale (MDnb)
The shale forms the lower part of steep valley sides and steep slopes
of tributary streams. Resistant layers form small discontinuous ledges
and minor waterfalls in streams.
The shale yields little or no water to wells. Seepage springs are present
at numerous horizons, but most go dry during late summer and fall.
Cumberland Formation, Leipers Limestone, Catheys Formation (Ocl)
These rocks form moderate to steep slopes and bluffs near the Cumberland
River. Limestone layers, interbedded with shales, form discontinuous
ledges along hillsides in some areas.
In lowland areas bordering large streams, these formations yield enough
water for a domestic supply (more than 500 gallons per day). Elsewhere
they yield little water to wells, but small quantities of water to springs.
Deep wells generally yield sulfurous water or brines.
The U.S. Geological Survey's Hydrologic
Atlas Series, published cooperatively with the Kentucky Geological
Survey, provides hydrologic information for the entire state.
to "Groundwater Resources in Kentucky"