LOCATION OPEQUON                 WV+KY MD MO OH PA TN VA

Established Series
Rev. JCB, MDJ
04/2014

OPEQUON SERIES

MLRA(s): 116A, 121, 124, 128, 147
Depth Class: Shallow
Drainage Class (Agricultural): Well drained
Saturated Hydraulic Conductivity Class: Moderately high to moderately low
Permeability Class (obsolete): Moderate to slow
Landscapes: Limestone uplands; mountains, hills, valleys, karst
Parent Material: Residuum weathered from relatively pure limestone or dolomite. In some areas the bedrock and the solum may contain chert.
Slope: 0 to 100 percent
Mean Annual Air Temperature (type location): 52 degrees F.
Mean Annual Precipitation (type location): 40 inches

TAXONOMIC CLASS: Clayey, mixed, active, mesic Lithic Hapludalfs

TYPICAL PEDON: Opequon silty clay loam idle field, rock outcrop. (Colors are for moist soil.)

Ap--0 to 10 inches; dark brown (10YR 3/3) silty clay loam; moderate fine and medium granular structure; friable, slightly sticky, slightly plastic; common fine and medium roots; 1 percent limestone fragments; many fine roots; slightly alkaline (limed); abrupt smooth boundary. (4 to 10 inches thick)

Bt1--10 to 17 inches; yellowish red (5YR 4/6) clay; moderate medium and coarse subangular blocky structure; firm, sticky, plastic; few fine and medium roots; many faint discontinuous, yellowish red (5YR 4/6) clay films and pressure faces on ped faces; 1 percent limestone fragments; slightly acid; clear wavy boundary. (3 to 10 inches thick)

Bt2--17 to 19 inches; strong brown (7.5YR 4/6) silty clay; weak coarse subangular blocky structure; firm, sticky, plastic; few fine roots; common distinct, discontinuous yellowish red (5YR 4/6) clay films and pressure faces on ped faces; 2 percent limestone fragments; slightly acid becoming moderately alkaline and strongly effervescent about one inch above limestone bedrock; abrupt irregular boundary. (combined thickness of Bt 5 to 16 inches)

R--19 inches; hard limestone bedrock

TYPE LOCATION: Jefferson County, West Virginia; on Route 45 at the Berkley County Line, about 0.35 miles east to Winebrenner Road, about 200 feet South on Sheperdstown topographic quadrangle: lat 39 deg 26 min. 23 sec / long 77 deg 57 min 0 sec , elevation 436 feet.

RANGE IN CHARACTERISTICS:

Solum Thickness: 12 to 20 inches
Depth to Bedrock: 12 to 20 inches
Rock Fragment content: Fragments of limestone and chert range from 0 to 35 percent, by volume, throughout the soil
Soil Reaction: Strongly acid to moderately alkaline.
Other features--Some pedons have B horizons which strongly effervesce in the lower part.

Range of Individual Horizons:

A or Ap horizon:
Color--hue of 10YR to 5YR, value of 3 to 6, and chroma of 1 to 4. A horizons with values of less than 3.5 moist, and 5.5 dry, are less than 7 inches thick
Texture (fine-earth fraction)--silt loam, clay loam, silty clay loam, silty clay, or clay where severely eroded

Bt horizon:
Color--dominant hue of 7.5YR to 2.5YR, but includes 10YR, value of 4 or 5, and chroma of 4 to 8. Texture (fine-earth fraction)--silty clay loam, silty clay, or clay.

BC horizon (if it occurs):
Color--dominant hue of 7.5YR to 2.5YR, but includes 10YR, value of 4 or 5, and chroma of 4 to 8. Texture (fine-earth fraction)--silty clay loam, silty clay, or clay.
Other features-- In some pedons, the BC horizon is mottled immediately above the lithic contact but more than 10 inches below the top of the argillic horizons.

C horizon (if it occurs):
Color--dominant hue of 7.5YR to 2.5YR, but includes 10YR, value of 4 or 5, and chroma of 4 to 8. Texture (fine-earth fraction)--silty clay loam, silty clay, or clay. Other features-- In some pedons, the C horizon is calcareous.

COMPETING SERIES:
Cynthiana soils-- formed in residuum from limestone of medium to high phosphate content and have Bt horizons with hue yellower than 7.5YR.

GEOGRAPHIC SETTING:
Landscapes: Limestone uplands; mountains, hills, valleys, karst
Landforms: Mountain slope, hillslope, valley side, karst valley. Rock outcrops are commonly associated with Opequon soils.
Hillslope Profile Positions: summits, shoulders, backslopes
Parent Material: Residuum weathered from relatively pure limestone or dolomite. In some areas the bedrock and the solum may contain chert.
Slope: 0 to 100 percent
Elevation: 330 to 3000 feet
Frost-free period: 130 to 190 days
Mean Annual Air Temperature: 48 to 58 degrees F.
Mean Annual Precipitation: 35 to 50 inches

GEOGRAPHICALLY ASSOCIATED SOILS:
All of the following geographically associated soils are more than 20 inches deep to bedrock: Bratton soils, Caneyville soils, Carbo soils, Chilhowie soils, Edom soils, Elliber soils, Faywood soils, Funkstown soils, Hagerstown soils, Murrill soils, Oaklet soils, Poplimento soils, Vertrees soils, and Watahala soils

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage Class (Agricultural): Well drained
Internal Free Water Occurrence: Very deep and absent
Index Surface Runoff: Negligible to very high
Saturated Hydraulic Conductivity Class: Moderately high to moderately low
Permeability Class (obsolete): Moderate to slow
Shrink-swell Potential: High
Flooding Frequency and Duration: None
Ponding Frequency and Duration: None

USE AND VEGETATION:
Major Uses: Largely in permanent pasture. In some areas, non-rocky areas are used for crops.
Dominant Vegetation: Where cultivated--alfalfa, small grains, corn. Where wooded--native vegetation was mainly mixed oaks. Cedars are common on unmanaged pasture and abandoned fields.

DISTRIBUTION AND EXTENT:
Distribution: Kentucky, Maryland, Missouri, Ohio, Pennsylvania, Virginia, and West Virginia.
Extent: Moderate

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia

SERIES ESTABLISHED: Madison County, Kentucky, 1970.

REMARKS:
Diagnostic horizons and soil characteristics recognized in this pedon are:
Ochric epipedon--the zone from 0 to 10 inches (Ap horizon)
Argillic horizon--the zone from 10 to 19 inches (Bt horizons)
Lithic feature--hard limestone bedrock at 19 inches (R horizon).

Other soil features identified with this pedon:
Series control section--the zone from 10 to 19 inches

Revisions made 11/2006, change the type location and update geographically associated soils. New pedon description.

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National Cooperative Soil Survey
U.S.A.