LOCATION TOMS VA+WVEstablished Series
TAXONOMIC CLASS: Fine, mixed, semiactive, mesic Aeric Endoaqualfs
TYPICAL PEDON: Toms silt loam, on a 2 percent slope in a pasture on a low terrace adjacent to the floodplain of the Shenandoah River. (Colors are for moist soil)
Ap--0 to 10 inches; dark grayish brown (10YR 4/2) silt loam; many fine prominent yellowish red (5YR 4/6) mottles and few fine faint brownish yellow (10YR 6/6) mottles; weak medium granular structure; friable, slightly sticky, nonplastic; many fine roots; common fine and medium discontinuous pores; common fine manganese concretions; 2 percent gravel; moderately acid; abrupt smooth boundary. (4 to 12 inches thick)
BA--10 to 21 inches; pale brown (10YR 6/3) silt loam; common fine and medium distinct gray (10YR 6/1) mottles, common fine prominent red (2.5YR 4/6) mottles, and common fine distinct grayish brown (10YR 5/2) mottles; moderate medium angular blocky structure; friable, sticky, slightly plastic; few fine roots; common coarse and many fine and medium pores; few faint clay films on faces of peds; common fine manganese concretions; slightly acid; clear wavy boundary. (0 to 12 inches thick)
Bt1--21 to 26 inches; yellowish brown (10YR 5/4) clay; common fine distinct grayish brown (10YR 5/2) and gray (10YR 6/1) mottles and common fine prominent red (2.5YR 4/6) mottles; moderate medium angular blocky structure; friable, sticky, plastic; few fine discontinuous pores; many distinct clay films on faces of peds; common fine manganese concretions; 2 percent gravel; neutral; clear wavy boundary.
Bt2--26 to 32 inches; strong brown (7.5YR 5/8) very cobbly clay; many fine and medium prominent gray (N5/) mottles; moderate fine and medium angular blocky structure; friable, sticky, plastic; few fine roots; many distinct clay films on faces of peds; common fine manganese concretions; 45 percent cobbles and gravel; neutral; abrupt smooth boundary. (Combined thickness of the Bt horizon is 30 to 50 inches)
2Btg--32 to 44 inches; gray (5Y 6/1) silty clay; many medium prominent strong brown (7.5YR 5/8) mottles; moderate medium subangular blocky structure; firm, sticky, plastic; common distinct clay films on faces of peds; 5 percent strongly weathered shale channers; slightly acid; clear smooth boundary. (0 to 20 inches thick)
2C--44 to 62 inches; yellowish brown (10YR 5/8) and gray (5Y 6/1) very channery silty clay loam; massive; sticky, plastic; 50 percent shale channers; slightly alkaline; abrupt smooth boundary.
2R--62 inches; hard shale bedrock.
TYPE LOCATION: Shenandoah County, Virginia; about .2 mile northwest of intersection of VA-747 and VA-651, 1,000 feet north of VA-651.
RANGE IN CHARACTERISTICS: The thickness of the solum ranges from 40 to 60 inches or more. Depth to bedrock is 60 inches or more. Gravel-size rock fragments make up 0 to 5 percent of the A horizon and upper part of the B horizon. Gravel and cobble-size rock fragments make up 0 to 50 percent of the lower part of the Bt horizon. Channer-size rock fragments of shale make up 0 to 60 percent of the 2B and 2C horizons, where present. The soil ranges from moderately acid through mildly alkaline throughout.
The A horizon has hue of 7.5YR or 10YR, value of 3 through 5, and chroma of 2 through 4. It is silt loam or loam.
The BA horizon, where present, has hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 3 through 8. It is loam or silt loam.
The Bt horizon is neutral or has hue of 7.5YR through 5Y, value of 5 through 7, and chroma of 1 through 8. In the fine-earth fraction it is clay loam, silty clay loam, silty clay, or clay.
The C horizon has a range for color and texture the same as that given for the Bt horizon. Discontinuities are common in the substratum and include textures of sandy loam and sandy clay loam.
COMPETING SERIES: These are the Aden, Crosby, Jeddo, Library, McGary, Parsippany, Pyrmont, Randolph, and Savona. Aden soils developed in Triassic alluvial sediments and have lower reaction throughout. Crosby, Jeddo, and Pyrmont soils developed in calcareous glacial till. Library soils are 40 to 60 inches to calcareous shale or thin bedded limestone. McGary soils formed in lacustrine deposits and have a 24 to 40 inch solum. Parsippany soils are in large basin areas and have lamella in the control section. Randolph soils are 20 to 40 inches to limestone bedrock. Savona soils formed in glacial outwash and are underlain with sand and gravel.
GEOGRAPHIC SETTING: Toms soils are on low stream terraces and slackwater areas along streams and intermittent drainageways. Slopes range from 0 to 8 percent. The soils formed in clayey alluvial deposits. Mean annual precipitation ranges from 35 to 40 inches and mean annual temperature ranges from 48 to 56 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the well drained Berks, Gilpin, and Weikert soils on the uplands and the Allegheny, Cotaco, Maurertown, and Monongahela soils on adjacent terraces. Allegheny, Cotaco, and Monongahela soils have less clay and less gray colors throughout than Toms soils. Maurertown soils have a dominantly gray matrix throughout. Berks and Weikert soils are shallower to bedrock and Monongahela soils have a fragipan.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained with slow to medium runoff. Permeability is slow. A perched high water table is at a depth of 1/2 foot to 1 1/2 feet from November through April of most years. Flooding ranges from none to rare.
USE AND VEGETATION: Most areas are in pasture. Native vegetative is mostly red maple, sweetgum, yellow-poplar, and northern red oak.
DISTRIBUTION AND EXTENT: Virginia and possibly Pennsylvania and West Virginia. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Shenandoah County, Virginia, 1988.
REMARKS: These soils have previously been included in the Tygart series.
The major diagnostic horizons and features recognized in
this pedon are:
a. Ochric epipedon - The zone from the surface to a depth of 21 inches (Ap and BA horizons).
b. Argillic horizon - The zone from 21 to 44 inches (Bt and 2Btg horizons).
c. Lithologic discontinuity - Change in parent material and rock fragments at 32 inches.
CEC class based on similar soils and laboratory data.
The 1/2006 revision updates this soil to the 9th Edition of the Keys to Soil Taxonomy (2003). The CEC activity class placement is based on similar soils and available laboratory data. Class placement may be revised in the future when additional laboratory data becomes available.
Competing series, pedon descriptions (including horizon nomenclature and/or descriptive terms), and other sections on the OSD were not revised (LWH-JHW-DGF 01/2006). Previous revision date: 10/90
Revisions made (11/2006) to update range in characteristics of C horizon.
ADDITIONAL DATA: Particle size and chemical data from the site location are available from Virginia Polytechnic Institute and State University.