LOCATION OAKLET VAEstablished Series
TAXONOMIC CLASS: Very-fine, mixed, semiactive, mesic Vertic Paleudalfs
TYPICAL PEDON: Oaklet silt loam - on a 5 percent slope in a pasture. (Colors are for moist soil.)
Ap--0 to 7 inches; dark yellowish brown (10YR 4/4) silt loam; common medium distinct strong brown (7.5YR 5/6) mottles; moderate fine granular structure; friable, sticky, plastic; many fine and medium roots; one percent iron manganese concretions; neutral; abrupt wavy boundary. (4 to 9 inches thick)
Bt1--7 to 17 inches; strong brown (7.5YR 5/6) clay; strong fine and medium subangular blocky structure; firm, very sticky, very plastic; common fine and medium roots; many medium clay films on faces of peds; slightly acid; diffuse smooth boundary. (5 to 12 inches thick)
Bt2--17 to 27 inches; strong brown (7.5YR 5/6) clay; strong fine and medium subangular blocky structure; firm, very sticky, very plastic; few fine roots; continuous medium clay films on faces of peds; strongly acid; diffuse smooth boundary. (5 to 12 inches thick)
Bt3--27 to 42 inches; strong brown (7.5YR 5/6) clay; many medium distinct yellowish brown (10YR 5/6) mottles; moderate coarse prismatic structure parting to strong medium subangular and angular blocky; firm, very sticky, very plastic; few fine roots; continuous medium clay films on faces of peds; strongly acid; diffuse smooth boundary. (12 to 17 inches thick)
Bt4--42 to 60 inches; strong brown (7.5YR 5/6) clay; many medium distinct yellowish brown (10YR 5/6) and very pale brown (10YR 7/3) mottles; moderate coarse prismatic structure parting to strong medium subangular and angular blocky; firm, very sticky, very plastic; continuous medium clay films on faces of peds; strongly acid; diffuse smooth boundary. (14 to 20 inches thick)
Bt5--60 to 90 inches; strong brown (7.5YR 5/6) clay; many medium distinct light gray (10YR 7/1) and yellowish red (5YR 5/8) mottles; moderate coarse prismatic structure parting to moderate medium subangular blocky; firm, very sticky, very plastic; many medium clay films on faces of peds; common slickensides; strongly acid.
TYPE LOCATION: Clarke County, Virginia; 0.7 mile southwest of the junction of Highways U.S. 17 and 50 and VA-644 and 0.2 miles east of VA-644.
RANGE IN CHARACTERISTICS: Solum thickness is greater than 60 inches. Depth to hard limestone bedrock ranges from 5 to more than 14 feet. Content of coarse fragments, commonly chert, ranges from 0 to 35 percent by volume in the A horizon and from 0 to 15 percent by volume in the B horizon. Some pedons contain concretions of secondary lime in the lower part of the B horizon. Reaction ranges from very strongly acid to slightly acid in the A horizon and in the upper part of the B horizon, unless the soil has been limed. Reaction in the lower part of the B horizon ranges from very strongly acid to moderately alkaline.
The Ap or Al horizon has hue of 10YR or 7.5YR, value of 3 through 6, and chroma of 2 through 6. Horizons with value of 3 and chroma of 2 or 3 are less than 7 inches thick. Texture is loam, silt loam, or silty clay loam, or their cherty analogues.
The Bt horizon has hue of 7.5YR or 10YR, value of 4 through 6, and chroma of 4 through 8. Most pedons have high chroma mottles in the lower part of the Bt horizon. Some pedons have mottles with chroma of 2 or less below 40 inches. It is clay.
The BC and C horizons, where present, have matrix colors and mottles similar to the lower part of the Bt horizon. It is clay or silty clay or their shaly analogues.
COMPETING SERIES: These are the similar Gepp and Swimley series. Gepp and Swimley soils have less than 6 cm of shrink-swell within 100 cm and have hue redder than 7.5YR in the Bt horizon.
GEOGRAPHIC SETTING: Oaklet soils are on gently undulating to steep upland slopes in the Shenandoah Valley. Slopes range from 2 to 15 percent. Rock outcrops occur in some places. These soils formed in material weathered from limestone bedrock of Middle Ordovician Age. The bedrock commonly contains stringers of chert and shale. These limestones contain thin metabentonitic (altered volcanic ash) beds from which the soils inherit montmorillonitic clays. Mean annual temperature is about 53 degrees F and mean annual precipitation is about 35 inches near the type location.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Carbo, Endcav, Frederick, Hagerstown, Lodi, Pagebrook, Poplimento, and Swimley 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; slow permeability.
USE AND VEGETATION: Most of these soils are used for pasture or cultivated crops with a minor acreage in woodland. Crops include small grain, corn, and hay. Woodland is mostly upland oaks, yellow poplar, hickory, maple, eastern red cedar, and Virginia pine.
DISTRIBUTION AND EXTENT: Virginia and possibly West Virginia, Maryland, Pennsylvania, and Tennessee. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Clarke County, Virginia, 1980.
REMARKS: These soils were formerly included with the Carbo, Frederick, and Hagerstown series. CEC and LE from NASIS data from Clarke County, Virginia.
Diagnostic horizons and features recognized in this pedon are:
a. Ochric epipedon - the zone from the surface of the soil to 7 inches. (A horizon)
b. Argillic horizon - the zone from 7 to 90 inches. (Bt horizon)
c. Vertic properties - linear extensibility of more than 6.0 cm between the surface and a depth of 100 cm.
The 10/2005 revision updates this soil to the 9th Edition of the Keys to Soil Taxonomy (2003). CEC class and shrink-swell based on 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 and mineralogy analyses - sample numbers S69VA22-17(1-8) by Virginia Polytechnic Institute and State University Laboratory.
SIR VA0138 MLRA 147 REVISED = 10/25/05 RE, JWB