Table 1.--Generalized section of geologic formations and their water-bearing properties* (from Gutentag et al., 1981).
 
System
Series
Stratigraphic
unit
Thickness,
Feet
 Physical character
Water supply
         
 Quaternary  Pleistocene Alluvium 0-80 Stream-laid deposits ranging from silt and clay to 
sand and gravel that occur along principal stream valleys.
Yields to wells range from 500 to more  than 1,000 gal/min in the Arkansas
River valley; 50 to 500 gal/min in the
Pawnee River valley; and 50 to 1,000 gal/min in the Cimarron River valley.
Dune sand 0-75 Fine to medium quartzose sand with small amounts of clay, silt, and coarse sand formed into mounds and ridges by the wind. Lies above the water table and does 
not yield water to wells. The sand 
has a high infiltration rate and
is important as area of ground-
water recharge.
    Loess 0-45 Silt with subordinate amounts of very fine sand
and clay deposited as windblown dust.
Lies above the water table and doesnot yield water to wells. Serves as
minor area of ground-water recharge.
    Undifferentiated
deposits
0-550 Sand, gravel, silt, clay, and caliche overlie
Ogallala Formation when both formations are present;composite of stream-laid and windblown deposits.
The sand and gravel of the undiffer-
entiated Pleistocene deposits and
the Ogallala Formation are the
Tertiary Pliocene Ogallala
Formation
0-500 Poorly sorted clay, silt, sand, and gravel generally
calcareous; when cemented by calcium carbonate,
Forms caliche layers or mortar beds.
principal water-bearing deposits in 
the area. Yields range from 100 to
3,100 gal/min.
 Cretaceous  Upper Cretaceous Niobrara Chalk 0-250 Upper unit (Smoky Hill Chalk Member)--yellow to
orange-yellow chalk and light- to dark-gray beds
of chalky shale. Lower unit (Fort Hays Limestone
Member)--consists of a white to yellow massive
chalky limestone: contains thin beds of dark-gray
chalky shale.
Generally not considered an aquifer. Initially (1968-72), yielded 500 to 
2,500 gal/min to wells in northern
Finney and eastern Kearny Counties
where the Fort Hays Limestone Member has been honeycombed by fractures and solution openings. Because of increased irrigation development, yields have been reduced by 100 to as much as 2,000 gal/min.
  Carlile Shale 0-330 Upper unit consists of a dark-gray to blue-black
noncalcareous to slightly calcareous shale that
locally is interbedded with calcareous silty very
fine-grained sandstone. Lower part consists of
very calcareous dark-gray shale and thin gray
interbedded limestone layers.
Sandstone in upper part may yield
5 to 10 gal/min to wells.
  Greenhorn
Limestone
0-200 Chalky light yellow-brown shale with thin-bedded
limestone. Dark-gray calcareous shale and light-
gray thin-bedded limestone; contains layers of
bentonite.
Not known to yield water to wells
in southwestern Kansas.
    Graneros
Shale
0-130 Dark-gray calcareous shale interbedded with black
calcareous shale; contains thin beds of bentonite.
Also contains thin-bedded gray limestone and fine-
grained silty sandstone layers.
Not known to yield water to wells
in southwestern Kansas.
  Lower Cretaceous Undifferentiated
rocks
0-450 Upper unit (Dakota Formation)--brown to gray fine-
to medium-grained sandstone; interbedded with gray sandy shale and varicolored shale; contains lignite lenses (0-160 feet). Middle unit (Kiowa Formation)--dark-gray to black shale; interbedded with light yellow-brown and gray sandstone (0-150 feet). Lower unit (Cheyenne Sandstone)--gray and brown very fine-to medium-grained sandstone; interbedded with dark-gray shale (0-125 feet).
The sandstone units commonly yield
from 50 to 500 gal/min to wells. 
Yields of more than 1,000 gal/min
are reported in a few areas. Water
may be more mineralized in the lo-
wer unit than in the upper unit.
Jurassic Upper Jurassic Undifferentiated
rocks
0-350 Dark-gray shale; interbedded with grayish-green and
bluish-green calcareous shale. Contains very fine-
to medium-grained silty sandstone and some thin
limestone beds at the base.
In Morton and Stanton Counties, sand-stone beds are yielding in combination with the overlying Lower Cretaceous units. In the northernmost
counties where the aquifer is deepest,
the water may be mineralized.
 Permian Upper
Permian
Big Basin
Formation
0-160 Brick-red to maroon siltstone and shale; contains
very fine-grained sandstone.
Where not highly mineralized, may
yield small quantities of usable
water for domestic and stock pur-
poses.
  Day Creek
Dolomite
0-80 White to pink anhydrite and gypsum; contains inter-
bedded dark-red shale.
Solution cavities have yielded large
quantities (300 to 1,000 gal/min)
of high sulfate water to wells
in Morton County.
  Whitehorse
Formation
100-350 Red to maroon fine-grained silty sandstone, silt-stone, and shale. Fresh to highly mineralized water. 
Not known to yield significant 
amounts of water to wells in south-
western Kansas.
  Lower
Permian
Dog Creek
Formation
15-60 Maroon silty shale, siltstone, very fine sand-
stone, and thin layers of dolomite and gypsum.

 

Not known to yield significant
amounts of water to wells in south-
western Kansas. Water probably
highly mineralized.
  Blaine
Formation
20-150 Generally consists of four gypsum and anhydrite
beds separated by red shale; contains bedded ha-
lite at some sites.
Not known to yield significant
amounts of water to wells in south-
western Kansas. Water probably
highly mineralized.

 

*The classification and nomenclature of the stratigraphic units used in this report are those of the Kansas Geological Survey and differ somewhat from those of the U.S. Geological Survey