LOCATION SWIMLEY VAEstablished Series
TAXONOMIC CLASS: Very-fine, mixed, semiactive, mesic Typic Paleudalfs
TYPICAL PEDON: Swimley silt loam - on a 5 percent slope in a cultivated field. (Colors are for moist soil.)
Ap--0 to 9 inches; reddish brown (5YR 4/4) silt loam; moderate fine granular structure; friable, slightly sticky, slightly plastic; many fine roots; many fine and medium pores; 5 percent chert fragments; neutral; abrupt smooth boundary. (5 to 12 inches thick)
Btl--9 to 14 inches; reddish brown (5YR 4/4) silty clay loam; moderate medium subangular blocky and moderate fine granular structure; friable, sticky, plastic; common fine roots; many medium clay films on faces of peds; l percent chert fragments; moderately acid; clear smooth boundary. (0 to 10 inches thick)
Bt2--14 to 29 inches; red (2.5YR 4/6) clay; strong fine and medium angular blocky structure; firm, sticky, plastic; common fine roots; continuous medium clay films on faces of peds; strongly acid; gradual smooth boundary. (5 to 20 inches thick)
Bt3--29 to 55 inches; red (2.5YR 4/6) clay; strong fine and medium angular blocky structure; firm, sticky, plastic; few fine roots; continuous medium clay films on faces of peds; very strongly acid; diffuse smooth boundary. (15 to 30 inches thick)
Bt4--55 to 99 inches; red (2.5YR 4/6) clay; few medium distinct light brownish gray (lOYR 6/2) and reddish brown (5YR 4/4) mottles; moderate medium and fine subangular blocky structure; firm, sticky, plastic; many medium clay films on faces of peds; very strongly acid.
TYPE LOCATION: Clarke County, Virginia; 0.3 miles west of the
RANGE IN CHARACTERISTICS: Solum thickness and depth to hard bedrock is more than 60 inches. Coarse fragments, usually chert, and less than inches in diameter, range from 0 to 10 percent in the A and B horizons. The BC and C horizons, where present, also contain from 5 to 50 percent highly weathered siltstone and shale fragments. The soil ranges from very strongly acid to neutral throughout unless limed.
The Ap or A horizon has hue of 5YR through l0YR, value of 3 through 6, and chroma of 2 through 5. Horizons with value of 3 and chroma of 2 or 3 are less than 7 inches thick. It is silt loam, silty clay loam, or clay. Clay textures commonly are in eroded areas.
The Bt horizon has hue of l0R through 5YR, value of 4 or 5, and chroma of 4 through 8. Subhorizons of some pedons have a value of 3. The lower part of the B2t horizon often contains mottles with chromas of 2 through 6. The Bt horizon is clay and contains more than 60 percent clay in the control section. In some pedons the upper part of the Bt horizon, immediately below the A horizon, is silty clay loam or silty clay and has hue of 7.5YR and chroma of 3.
The BC and C horizons, where present, have hue of l0R through 7.5YR, value of 4 through 7, and chroma of 4 through 8. They commonly have both high and low chroma mottles imparted by weathered siltstone and shale fragments. The BC and C horizons are clay.
COMPETING SERIES: These are the Gepp, Oaklet and Rollingstone series in the same family and the Bland, Carbo, Endcav, Frederick, Hagerstown, Lodi, Oshkosh, Pagebrook, and Poplimento series in closely related families. Gepp soils have 10 to 75 percent rock fragments in the horizons above the Bt horizon. Oaklet soils have more than 6 cm of shrink-swell within 100 cm and a hue browner than 5YR in the Bt horizon. Bland, Carbo, and Oshkosh soils have a solum less than 40 inches thick. Endcav soils have a solum 40 to 60 inches thick. Frederick soils are Paleudults. Hagerstown, Lodi, and Poplimento soils have a solum that decreases by more than 20 percent clay content within 60 inches. Pagebrook soils have smectitic clay mineralogy and they are not as well drained as Swimley soils. Rollingstone soils receive less than 32 inches annual precipitation.
GEOGRAPHIC SETTING: Swimley soils are on gently undulating and rolling to very steep upland slopes. Slopes range from 2 to 50 percent, commonly being 2 to 8 percent. Rock outcrops occur in some areas. These soils formed in residuum weathered from bluish-gray limestones that commonly contain strata of siltstone and shale. In some places the upper part of the solum is formed in up to 16 inches of silty material. Mean annual temperature ranges from 50 degrees to 57 degrees F and mean annual precipitation ranges from 32 to 44 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Carbo Endcav, Frederick, Hagerstown, Lodi, Oaklet, Pagebrook, and Poplimento series as well as the Opequon and Timberville soils. Opequon soils have bedrock at less than 20 inches. Timberville soils occur in depressions and at the heads of drainageways and they have thicker surface layers.
DRAINAGE AND PERMEABILITY: Well drained, slow to medium runoff; moderate permeability.
USE AND VEGETATION: Most of these soils are used for pasture or cultivated crops with a minor acreage in forest. Crops include small grain, corn, and mixed hay. These soils probably developed under a deciduous forest; however, most of these forests have been cleared and the present vegetation consists of grasses.
DISTRIBUTION AND EXTENT: Virginia, Indiana, and possibly West Virginia and Pennsylvania. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Clarke County, Virginia, 1980.
REMARKS: Swimley soils were formerly included with the Hagerstown, Benevola, and Decatur series. Gepp soils appear to have formed in similar parent material in the Ozark Highlands. The range in characteristics for the Gepp and Swimley soils are very similar as are the mean annual precipitation and temperature. However, rainfall distribution and/or unknown chemical and physical differences between the two soils apparently result in significantly higher crop yields on the Swimley soils.
Revised 11/14/05 RE, JWB
The 11/2005 revision updates this soil to the 9th Edition of the Keys to Soil Taxonomy (2003). CEC class is assigned based on the NASIS data from Clarke County, Virginia. Class placement may be revised in the future when laboratory data are reviewed or become available. Competing series, pedon description (including horizon nomenclature and/or descriptive terms), and other sections on the OSD were not revised.
ADDITIONAL DATA: Chemical, physical, and mineralogical analyses of samples S69VAa22-18-(1-6*) for the typifying pedon. Chemical and mechanical analyses f samples S69Va22-16-(1-5) for another pedon. All data by V.P.1. and State University, Soil Survey Laboratory.