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Alluivum (Qa) and Glacial Sediments (Qg)
Topography
The sediments form flood plains and terraces, as much as 6 miles wide,
in the Ohio River valley. They form broad flat areas in the valleys
of the Salt River and large tributaries. Some Ohio River terraces are
as much as 80 feet above normal pool stage. Flats are dissected by short,
steep-sided gullies near tributaries.
Hydrology
The sediments yield 200 to 500 gal/min (gallons per minute) to most
wells that penetrate the full thickness of alluvium in the Ohio Valley,
and more than 1,000 gal/min to large-diameter wells. The sediments yield
100 to 500 gal/day to wells in tributary-stream valleys, and may yield
more than 500 gal/day where gravel is present. Water is hard, and the
iron content may be high near the Ohio River valley walls.
Middle Mississippian Limestone (St. Louis, Salem, Harrodsburg Limestones)
(Msh)
Topography
These limestones form the tops of some of the high ridges and knobs
in southwestern Jefferson County.
Hydrology
These limestones yields 100 to 500 gal/day to drilled wells on broad
uplands, but almost no water on narrow ridges. They do yield water to
small springs in edges of escarpment. Water is hard but otherwise of
good quality.
Borden Formation (Mbf, MDbb)
Topography
The Borden forms the main part of the Muldraugh escarpment and many
outlying knobs. Resistant rocks of the Muldraugh member cap the escarpment
and larger knobs. The New Providence member underlies the lower, dissected
slopes of the knobs and escarpment.
Hydrology
The Borden yields 100 to 500 gal/day to wells in valley bottoms, and
may yield more than 300 gal/day where thick siltstone beds occur at
and below stream level. It yields almost no water to wells on hills,
but does yield water to small springs in the limestone and siltstone
beds. Water from the shale is soft, from the siltstone, hard, and from
the limestone, very hard. At shallow depths below stream level, water
may contain salt, sulfate, or iron. The silty shale and siltstone are
favorable for dug wells, common in this area. Most dug wells yield less
than 500 gal/day and many yield little or go dry in late summer and
early fall.
New Albany Shale (MDnb)
Topography
The New Albany forms broad, flat areas in southwest-central Jefferson
County.
Hydrology
The New Albany yields 100 to 500 gal/day to shallow drilled wells in
broad, flat areas, but almost no water to drilled wells on hillsides.
It does yield water to small springs and dug wells. Water is hard and
from depths greater than above 50 feet may contain hydrogen sulfide
and iron.
Devonian Limestones (Sellersburg Limestone, Jeffersonville Limestone)
(Dsj)
Topography
These limestones form rolling uplands in northern Jefferson County,
with sinkholes and underground drainage.
Hydrology
These limestones yield more than 500 gal/day to drilled wells in broad,
flat valleys or along streams on broad uplands. They also yield water
to springs. Water is hard.
Louisville Limestone (Slw)
Topography
The limestone forms moderately rolling uplands in south-central Jefferson
County, with some sinkholes and underground drainage. It forms cliffs
and ledges in valley sides.
Hydrology
The Louisville yields more than 500 gal/day to wells drilled in valley
bottoms or along streams on broad uplands, and as much as 50 gal/min
in places. It yields water to springs at contact with underlying Waldron
shale. Water is hard and may contain salt or hydrogen sulfide below
stream level.
Waldron Shale (Slw)
Topography
The Waldron forms slopes between limestone ledges on hillsides. Erosion
of shale in the Waldron undermines the overlying Louisville limestone.
Hydrology
The Waldron yields almost no water to wells or springs. It holds up
water in the overlying Louisville limestone and prevents recharge to
the underlying Laurel dolomite.
Laurel Dolomite (Slb)
Topography
The Laurel forms ledges and cliffs along streams.
Hydrology
The Laurel yields 100 to 500 gal/day to wells on broad ridges and along
streams. It also yields water to small springs at contact with underlying
Osgood formation. Water is hard.
Osgood Formation (Slb)
Topography
The Osgood forms slopes between ledges above and below.
Hydrology
The Osgood yields almost no water from shale. It does yield water to
seeps from limestone. The Osgood impedes recharge to underlying rocks.
Water is hard.
Brassfield Formation (Slb)
Topography
The Brassfield forms ledges on slopes and tops of small cliffs of underlying
Saluda limestone.
Hydrology
The Brassfield yields almost no water to wells, but does yield water
to seeps and small springs. Water is hard.
Drakes Formation (Saluda Dolomite, Bardstown, Rowland Members) (Od)
Topography
The Drakes forms moderately-dissected upland areas, with moderately
steep slopes where shale predominates and less steep slopes where limestone
predominates. Steep slopes occur along large streams and cliffs. Many
slopes are dotted with weathered limestone slabs. Solutional features
evident where thick limestone beds underlie streams.
Hydrology
The Drakes yields 100 to 500 gal/day to wells in large stream valleys,
and more where thick limestone is present. It yields almost no water
to wells on hillsides and ridges except in broad ridges in upper part
of formation. It does yield water to small springs. Water is hard and
may contain salt in valley bottoms but generally of good quality.
Grant Lake Limestone, Fairview Formation, Calloway Creek Limestone
(Oaf)
Topography
These formations create gently to moderately rolling uplands away from
major streams, more highly-dissected where shale content increases,
with small sinkholes, minor underground drainage, and broad, flat valleys
where limestone predominates. The lower part forms broad, flat ridges
between steep sided valleys cut into underlying shale of the Kope or
Clays Ferry formations.
Hydrology
These rocks yield 100 to 500 gal/day to drilled wells in broad valleys
and along streams in uplands, and more than 500 gal/day from thick limestone
beds in the broad valley bottoms. They yield almost no water to drilled
wells on hillsides or ridgetops, but do yield water to small springs
and seeps. The limestone bed,15 feet thick, in lower part of the Grant
Lake Limestone yields as much as 30 gal/min to springs. The sandy zone
near the base yields little water. Water is hard and in valley bottoms
may contain salt or hydrogen sulfide.
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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