LOCATION WEBBTOWN VAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, semiactive, mesic Ruptic-Alfic Eutrudepts
TYPICAL PEDON: Webbtown channery silt loam - in a pasture. (Colors are for moist soil.)
Ap--0 to 8 inches; brown (7.5YR 5/4) channery silt loam; moderate fine granular structure; friable, slightly sticky, slightly plastic; many fine and medium roots; 20 percent shale and siltstone fragments; neutral; clear smooth boundary. (6 to 10 inches thick)
Bw1--8 to 14 inches; brown (7.5YR 5/4) very channery silt loam; weak medium subangular blocky structure; friable, slightly sticky, slightly plastic; common fine roots; 40 percent shale and siltstone fragments; neutral; gradual smooth boundary. (0 to 9 inches thick)
Bw2--14 to 34 inches; strong brown (7.5YR 5/6) very channery silty clay loam; moderate medium subangular blocky structure; friable, sticky, plastic; few fine roots; Bt pockets and lenses of silty clay with few distinct clay films make up 25 percent of this horizon; common black coatings; 45 percent brownish yellow (10YR 6/6) soft shale and siltstone fragments; neutral; diffuse smooth boundary. (8 to 32 inches thick)
BC--34 to 50 inches; yellowish red (5YR 5/8) very channery silty clay; weak medium subangular blocky structure; friable, sticky, plastic; 45 percent brownish yellow (10YR 6/6) soft shale fragments; moderately acid; clear smooth boundary. (0 to 20 inches thick)
C1--50 to 60 inches; strong brown (7.5YR 5/8) extremely channery silt loam; massive; friable, sticky, plastic; 65 percent yellowish brown (10YR 5/6) and olive (5Y 5/4) soft shale and siltstone fragments; slightly acid; clear smooth boundary. (0 to 29 inches thick)
C2--60 to 72 inches; mixed yellowish red (5YR 5/6), strong brown (7.5YR 5/6), and brownish yellow (10YR 6/6) extremely channery silty clay; massive; friable, sticky, plastic; 60 percent soft shale and siltstone fragments; slightly acid.
TYPE LOCATION: Clarke County, Virginia; 0.3 mile west of Highway 08; 1.3 miles south southwest of junction of Highways 7 and 608.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 18 to 72 inches. Depth to hard shale, limestone, or fine-grained sandstone bedrock ranges from 20 to 72 inches or more. Rock fragment content, commonly shale and porous, very low density soft siltstone, ranges from 15 to 35 percent in the A horizon, from 35 to 75 percent in the B horizon, and from 50 to 80 percent in the C horizon, where present. Reaction ranges from strongly acid to slightly acid in the A horizon and upper part of the B horizon and from moderately acid to neutral in the lower part of the B horizon and in the C horizon.
The A or Ap horizon has hue of 7.5YR or 1OYR, value of 4 to 6, and chroma of 3 to 6. Texture is loam, silt loam, or silty clay loam in the fine earth fraction.
The B horizon has hue of 5YR to 1OYR, value of 4 to 6, and chroma of 4 to 8. It is silt loam, silty clay loam, silty clay, or clay in the fine earth fraction. Silty clay and clay textures are limited to the lower part of the B horizon.
The C horizon has colors similar to the B horizon. Texture ranges from silt loam to clay in the fine earth fraction. Some pedons have reddish colors inherited from bedrock.
COMPETING SERIES: Catoctin is the only other known series in this family. The Catoctin soils have a solum thickness of 12 to 24 inches, and are underlain with greenstone bedrock at a depth of 20 to 40 inches.
GEOGRAPHIC SETTING: Webbtown soils are on gently sloping to very steep uplands in the Appalachian Ridges and Valleys. Slopes range from 2 to 60 percent. Rock outcrops are common in many areas. These soils formed in residuum weathered from heterogeneous rock composed of interbedded shale, limestone, siltstone, and fine-grained sandstone. The bedrock has dips that range from about 45 degrees to 90 degrees. Mean annual temperature ranges from 54 to 58 degrees F. and mean annual precipitation ranges from 34 to 40 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Duffield, Hagerstown, Nicholson, Pagebrook, Poplimento, and Timberville soils. All of these soils have a continuous argillic horizon and less than 35 percent rock fragments in the particle-size control section. In addition, Hagerstown and Poplimento soils are clayey, Nicholson soils have a fragipan, Pagebrook soils are clayey and moderately well drained, and Timberville soils have thick surface layers and are in slight depressions and at the heads of drains.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; moderate permeability.
USE AND VEGETATION: Most of these soils are used for small grain, hay, and pasture with some areas in forest. A small acreage is used for apple and peach orchards, corn, and other row crops. These soils probably developed under deciduous forest vegetation. Most areas have been cleared at some time in the past.
DISTRIBUTION AND EXTENT: Virginia; 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
REMARKS: Diagnostic horizons and features recognized in this pedon are:
a. Ochric Epipedon - (Ap - Horizon) from the surface to 8 inches.
b. Cambic Horizon - (Bw1 and Bw2) from 8 to 34 inches.
c. Loamy skeletal - More than 35 percent rock fragments in the
particles - size control section.
Revisions 12/2005 Updates this soil to the 9th Edition of the Keys to Soil Taxonomy (2003). The CEC activity class placement is semiactive based on associated soils and the NASIS data from Clarke County, Virginia. Class placement may be revised in the future when laboratory data are available. In addition, horizon nomenclature and competing series were updated.
Previous revision DDR 5/85
ADDITIONAL DATA: Chemical, particle-size analysis, and engineering data of samples S70VA22-42(1-6) from the typical pedon (Virginia Polytechnic Institute and State University Soil Survey Laboratory).