|
Alluvium (Qa)
Topography
The alluvium forms narrow, discontinuous flood plains and small terraces
along the larger streams.
Hydrology
The alluvium is generally inadequate for a domestic supply, being too
thin and too fine-grained to yield much water. Water is hard.
Breathitt Group (Pbl) (Pikeville Formation)
Topography
The Breathitt Group underlies the valleys and forms the hills. Tops
of hills and ridges commonly are capped by sandstone. Shales form wide
valleys and moderate or gentle slopes on hills.
Hydrology
The Breathitt yields more than 500 gal/day to almost half of the wells
drilled in valley bottoms and more than 100 gal/day to about half the
wells drilled on hillsides and on ridges. Sandstones yield water to
most wells. Shales also yield water to many wells, and coal yields water
to a few. Near-vertical joints and openings along bedding plains yield
most of the water to wells. Waters are highly variable in chemical character
Corbin (Plc) and Rockcastle (Plr) Sandstone Members, Grundy, Alvy
Creek and Bee Rock
Formations (contains Lee type sandstone of the former Lee Formation)
Topography
Thick, resistant sandstones form tops of steep-sided ridges and knobs,
steep bluffs and cliffs. Shaly facies crop out in northwestern Laurel
County, forming a highly dissected area of winding ridges and steep-sided
hills. Some cliff-forming sandstone paleochannels have been cut through
shales of the Paragon Formation into limestone units of Late Mississippian
age.
Hydrology
In most of Laurel County these formations yield more than 500 gal/day
to about three-quarters of the wells drilled on hillsides and about
half the wells on hilltops. In valley bottoms and lowland areas bordering
streams yields are greater than 500 gal/day to more than three-quarters
of the wells. In northwestern Laurel County yields are more than 100
gal/day to about three-quarters of the wells drilled on hilltops. Yields
larger quantities of water to wells on hillsides and valley bottoms.
Sandstone is the principal aquifer, but shale yields water to some wells
and coal to a few. Joints and openings along bedding planes, best developed
in sandstone, supply most of the water to wells. Perched and semi-perched
water tables are common. Waters are generally soft or moderately hard
and contain noticeable amounts of iron.
Paragon Formation (Mpn, Mpk)
Topography
The Paragon forms moderate to steep slopes in mountain margin area where
capped by massive sandstone of Breathitt Group.
Hydrology
The Paragon yields almost no water. Impermeable shale may hold water
in overlying sandstone and conglomerate.
The U.S. Geological Survey's Hydrologic
Atlas Series, published cooperatively with the Kentucky Geological
Survey, provides hydrologic information for the entire state.
Previous--Next--Back
to "Groundwater Resources in Kentucky"
|