Alluvium (Qa) and Glacial Outwash Sediments (Qa)
These sediments form floodplains, valley bottoms, and terraces of the
Ohio River and tributaries, and valley-train deposits beneath terraces
along the Ohio River.
Drilled wells in the alluvium of the Ohio River yield several hundred
gallons a minute. The unconsolidated sediments yield enough water for
a modern domestic supply (more than 500 gallons per day) to nearly all
wells, but practically no water to wells in small valleys where they
are thin and fine-grained. Water ranges in hardness from 12 to 664 parts
per million and in dissolved solids from 53 to 1,220 parts per million.
Iron may be present in objectionable amounts.
The loess forms a thin mantle over alluvial deposits and bedrock over
much of the area near the Ohio River.
The loess is not an aquifer, but may yield small amounts of water to
a few wells. When saturated by rainfall, it transmits water to underlying
Tuscaloosa Formation (Kt)
The Tuscaloosa may occur in remnants of a channel eroded into the surface
of the Paleozoic rocks.
The Tuscaloosa is not significant as an aquifer. Most drilled wells
in the gravel of the Tuscaloosa Formation are adequate for a bailer
(more than 100 gallons per day). Yields are low, because of a clayey
matrix and poor sorting. Tripolitic clay is present locally, which tends
to clog well screens, and wells penetrating it are inadequate (less
than 100 gallons per day). Hardness of water from two wells sampled
was 26 and 57 parts per million, and dissolved solids, 50 and 76 parts per million.
Chert rubble occurs mostly in the subsurface. The surface of the Paleozoic
rocks locally has been reduced to a chert rubble by pre-Late Cretaceous
weathering of the chert-bearing limestone.
The chert rubble probably will yield more than enough water for domestic
use, and locally may yield sufficient water for small public supplies.
Yields are as large as 100 gallons per minute. Yields vary with the
saturated thickness of the rubble and characteristics of the rubbles
matrix. Hydrologic properties resemble those of gravel. The water level
in the rubble slopes downward from highs on the limestone surface toward
collapse structures (areas of thick chert rubble formed by solutional
collapse along fracture zones and former drainage channels). The water
is soft and has a low dissolved solids content, but may contain an objectionable
amount of iron, which probably is derived from the iron-rich clay that
commonly fills voids in the rubble.
Lamprophyre Dikes and Sills (Pl)
Not considered an aquifer.
Tradewater (Pt) and Caseyville (Pca) Formations
These rocks form dissected uplands and occur in downfaulted blocks of
the Western Kentucky Fluorspar District.
These formations will yield enough water for a modern domestic supply
to most wells in lowland areas bordering streams and locally in broad
upland areas. Wells in small upland areas generally are inadequate (less
than 100 gallons per minute).
Chesterian Formations (Kinkaid Limestone, Degonia Sandstone, Clore
Limestone, Palestine Sandstone, Menard Limestone, Waltersburg Sandstone,
Vienna Limestone, Tar Springs Sandstone, Glen Dean Limestone, Golconda
Formation, Cypress Sandstone, Paint Creek
Shale, Bethel Sandstone)
These formations yield small amounts to wells and springs in outcrop
areas. Water from Mississippian rocks underlying younger rocks contains
salt in objectionable amounts, if any water is found. Limestone formations
yield small to adequate supplies from solution openings. In lowland
areas bordering streams, some wells furnish enough for a domestic supply.
Most wells in upland areas are inadequate for a domestic supply. On
uplands, deep wells that penetrate solution openings in limestone may
produce more than 5 gallons per minute, but most deep wells on uplands
are inadequate for a domestic supply. Close to outcrop areas, particularly
near major escarpments, yields from perched water bodies generally are
inadequate during dry periods. Springs occur at the base of many limestone
formations where they crop out on escarpments and hillsides. Adjacent
to large upland areas, springs yield as much as 100 gallons per minute,
and low flows are more than 5 gallons per minute from some springs.
Kinkaid Limestone, Degonia Sandstone, Clore Limestone (Mcu)
These formations underlie gently rolling uplands having some sinkholes
and fairly steep slopes.
Palestine Sandstone (Mcu)
The Palestine forms a minor bench on hillsides, and underlies gently
Menard Limestone, Waltersburg Sandstone, Vienna Limestone (Mcu)
These rocks underlie flat uplands and form gentle slopes on hillsides.
Tar Springs Sandstone (Mcu)
The Tar Springs underlies gently rolling uplands and forms a minor bench
Glen Dean Limestone (Mcl)
The Glen Dean underlies gently rolling uplands, and forms a gradual
slope above the Hardinsburg bench.
Hardinsburg Sandstone (Mcl)
The Hardinsburg forms a minor escarpment, modified in many places by
faults. It underlies broad, rolling uplands.
Golconda Formation (Haney Limestone, Big Clifty Sandstone, Beech
Creek Limestone Members) (Mcl)
The Golconda underlies gently rolling uplands, and forms steep slopes
below the minor Hardinsburg sandstone escarpment.
Cypress Sandstone (Mcl)
The Cypress forms a major escarpment, but it is broken by faults in
the Western Kentucky Fluorspar District. The sandstone underlies broad
Paint Creek Shale (Mcl)
The Paint Creek forms moderate to rolling slopes below the Cypress Sandstone
escarpment; it has been modified by faults in the Western Kentucky Fluorspar
Bethel Sandstone (Mcl)
The Bethel forms the lowest major escarpment in the Western Kentucky
Fluorspar District. The escarpment is broken by faults. The Bethel underlies
broad, rolling uplands.
Renault Limestone (Mcl)
The Renault forms a moderate slope under the Bethel Sandstone escarpment,
except where modified by faults or a higher sandstone escarpment.
The limestone yields little or no water to wells. Small springs with
low flows of about 5 gallons per minute occur near the top of the formation.
Ste. Genevieve Limestone (Levias Limestone, Rosiclare Sandstone,
Fredonia Limestone Members) (Mgl)
The Ste. Genevieve underlies rolling karst uplands, and forms a moderate
slope under the Bethel Sandstone escarpment, except where modified by
faults. The Ste. Genevieve is exposed across large fault blocks in parts
of the Western Kentucky Fluorspar District.
These rocks yield 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. Springs
having low flows ranging from less than 10 gallons per minute to about
1,500 gallons per minute occur at or near stream level. Smaller springs
discharge from perched water bodies in upland areas, but many go dry
during late summer and fall.
St. Louis Limestone (Mgl)
The St. Louis underlies dissected uplands and ridges. It forms rolling
karst uplands in faulted parts of the Western Kentucky Fluorspar District.
Low flows of numerous springs that discharge from near the top of the
formation and near stream level range from less than 10 gallons per
minute to about 1,500 gallons per minute. Maximum flows range from less
than 100 gallons per minute to more than 100,000 gallons per minute.
Most springs are situated near minor rivers. In karst areas, drilled
wells generally produce enough water for domestic use. Some produce
more than 50 gallons per minute from large solution openings. Most wells
high above perennial streams are adequate. In nonkarst areas, yields
generally are lower than in karst areas; the number of solution openings
is fewer and their size smaller. Many wells are insufficient for domestic
use. Most springs are small and many go dry during late summer and fall.
Most wells high above perennial streams are inadequate.
Fort Payne Formation (Mbf)
The Fort Payne underlies dissected ridges between the Tennessee and
Cumberland Rivers. It is exposed in a fault scarp at Kuttawa.
The Fort Payne yields almost no water to wells where unweathered. Where
the limestone has been leached away and chert rubble is left, yields
may exceed 50 gallons per minute. Yields of most wells of moderate depth range
from 2 to 10 gallons per minute. Tripolitic clay may be present in some areas where
the formation yields little or no water to wells.
The U.S. Geological Survey's Hydrologic Atlas Series, published cooperatively
with the Kentucky Geological Survey, provides hydrologic information
for the entire state. Atlases for Crittenden County are HA-34,
to "Groundwater Resources in Kentucky"