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Alluvium (Qa)
Topography
The alluvium forms terraces and floodplains along the Cumberland River
and tributaries.
Hydrology
Most wells in the alluvium are inadequate for a domestic supply.
Ste. Genevieve Limestone Member of the Monteagle Limestone (Mgl)
Topography
The limestone underlies rolling and dissected karst areas, forming steep
bluffs along Lake
Cumberland.
Hydrology
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 contact with the underlying St. Louis Limestone.
St. Louis Limestone (Mgl)
Topography
The St. Louis forms steep bluffs along Lake Cumberland. It underlies
rolling karst areas, but commonly has less relief than karst in areas
underlain by the Ste. Genevieve Limestone. Close to Lake Cumberland
and tributaries the St. Louis is dissected. Resistant siltstone alternating
with nonresistant shale layers forms discontinuous minor benches on
hillsides.
Hydrology
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 are
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)
Topography
These formations underlie gentle to dissected rolling uplands, forming
steep bluffs where the limestone overlies rocks of Osagean age and along
Lake Cumberland. In some areas numerous small sinkholes occur in the
formation.
Hydrology
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. Springs low flows generally
are less than 5 gallons per minute.
Fort Payne Formation (Mbf), limestone bodies within Fort Payne (ls),
Knifley Sandstone
Member (Mfk)
Topography
These formations underlie dissected rolling uplands, forming steep valley
sides in maturely
dissected topography. Small valleys are steep and V-shaped. Siltstone
and chert form
discontinuous ledges on hillsides.
Hydrology
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 springs 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.
Borden Formation (MDbb)
Topography
The Borden forms the main part of Mississippian escarpment, ridges,
and knobs. Shale forms
dissected slopes, massive siltstone forms cliffs, and limestone forms
ledges on shale slopes.
Hydrology
The Borden yields 100 to 500 gallons per day to wells in valley bottoms.
It may yield more than 500 gallons per day to drilled wells in broad
valley bottoms from fractured sandy rocks near streams. It yields almost
no water to wells on hills. Water from wells drilled below stream level
may contain salt, sulfate, or iron less than 100 feet below the level
of the principal valley bottoms. Water from dug wells and small springs
is soft and has a low dissolved solids content Water from shale is soft;
from the siltstone, hard; and from the limestone, very hard. Because
much of this formation is soft and silty, it has been well suited to
the construction of dug wells in the past; such wells generally produce
less than 500 gallons per day and often go dry in late summer and fall.
Chattanooga Shale (MDnb)
Topography
Chattanooga Shale forms steep slopes near the base of the Cumberland
Escarpment and "knobs." It underlies small round hills (knobs) near
the base of the escarpment. Resistant layers in the Chattanooga form
small discontinuous ledges and minor waterfalls in streams.
Hydrology
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.
Laurel and Brassfield Dolomites, Osgood Formation (Slb)
Topography
Dolomite beds form resistant ledges on valley sides.
Hydrology
These rocks yield small quantities of water to wells near the Cumberland
River.
Cumberland Formation, Leipers Limestone, Catheys Formation (Ocl)
Topography
These formations create moderate to steep slopes and bluffs near the
Cumberland River. Limestone layers, interbedded with shales, form discontinuous
ledges along hillsides in some areas.
Hydrology
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, and 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.
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