LOCATION MANASSAS VA
Soils of the Manassas series are very deep moderately well drained to well drained and have moderate to moderately rapid permeability. They formed in colluvial and residual materials derived from shale, siltstone and conglomerate in the Piedmont Province. The mean annual temperature is about 53 degrees F, and the mean annual precipitation is about 40 inches. Slopes range from 0 to 7 percent.
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Ultic Hapludalfs
TYPICAL PEDON: Manassas silt loam - cultivated.
Ap--0 to 10 inches; dark reddish brown (5YR 3/4) silt loam; weak fine granular structure; very friable; many fine roots; few fine and medium pores; moderately acid; clear smooth boundary. (0 to 10 inches thick)
AB--10 to 16 inches; reddish brown (5YR 4/3) silt loam; weak fine granular and fine subangular blocky structure; very friable; common fine roots; few fine and medium pores; 2 percent weathered shale fragments up to 1 inch across; strongly acid; clear smooth boundary. (0 to 10 inches thick)
Btl--16 to 24 inches; dark reddish brown (5YR 3/4) silt loam; weak medium subangular blocky structure; friable; slightly sticky, slightly plastic; common fine roots; few medium pores; few faint clay films on faces of peds; few black mineral concretions; 5 percent weathered shale fragments up to 1 inch across; strongly acid; gradual smooth boundary.
Bt2--24 to 30 inches; reddish brown (5YR 4/4) silt loam; few fine faint yellowish brown (10YR 5/6) and pale brown (10YR 6/3) mottles; weak medium subangular blocky structure; friable; slightly sticky, slightly plastic; few fine roots; few medium pores; common distinct clay films on faces of peds; 5 percent weathered shale fragments up to 1 inch across; strongly acid; gradual smooth boundary. (Combined thickness of the Bt horizon is 12 to 35 inches)
BC--30 to 40 inches; reddish brown (5YR 4/4) silt loam; few fine distinct pale brown (10YR 6/3) mottles; weak fine subangular blocky structure; friable; slightly sticky, slightly plastic; common black mineral concretions; 10 percent weathered shale and conglomerate fragments up to 4 inches across; 2 percent quartz pebbles; very strongly acid; gradual wavy boundary. (4 to 16 inches thick).
C--40 to 60 inches; reddish brown (5YR 5/4) very channery silt loam; few fine faint yellowish red (5YR 5/8) and pinkish gray (5YR 6/2) mottles; weak granular structure; friable; 50 percent weathered shale fragments up to 4 inches across; 5 percent quartz pebbles; very strongly acid.
TYPE LOCATION: Loudoun County Virginia; 1 mile south of Leesburg VA. Near Virginia Route 621. Lat. 39.08875 and Long. -77.590358. NAD 83.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 30 to 60 inches. Depth to hard bedrock is greater than 60 inches. Rock fragments of shale, siltstone, conglomerate or quartz range from 0 to 15 percent in the A horizon and the upper part of the B horizon and from 10 to 60 percent in the lower part of the B horizon and C horizon. The soil is very strongly or strongly acid, unless limed.
The A horizon commonly has hue of 7.5YR or 5YR, value of 3 through 6, and chroma of 3 through 6. Horizons with value of 3 and chroma of 2 or 3 are less than 6 inches thick. The A horizon is silt loam, fine sandy loam, or loam.
Most pedons have an AB horizon with hue of 7.5YR or 5YR, value of 3 through 5, and chroma of 3 through 6. It is silt loam or silty clay loam.
The E horizon, where present, has hue of 5YR or 7.5YR value of 4 through 6 and chroma of 4 through 6. It is silt loam or loam.
The Bt horizon has hue of 5YR or 2.5YR, value of 3 through 5, and chroma of 3 through 6; dry color value is 5 or more. It is silt loam, clay loam, or silty clay loam. The lower part of the Bt horizon is mottled in most pedons.
The BC horizon has colors similar to the Bt2 horizon. It is silt loam, loam, or silty clay loam in the fine earth fraction.
The C horizon has hue of 2.5YR through 7.5YR, value of 3 through 6, and chroma of 3 through 8. It is silt loam or silty clay loam in the fine earth fraction. Cr horizons are in some pedons. They are commonly weathered shale or siltstone. Thin interbeds of sandstone are allowed.
COMPETING SERIES: The
Williamsburg series are in the same family. Athol soils contain rock fragments of sandstone and do not have mottles in the upper 40 inches. Bolton, Bookwood and Duffield soils have chert and limestone rock fragments. Brecknock, Carpenter, Door, Dormont, Frondorf, Morrison, Ryder, Washington, Westmoreland, Wheeling and Williamsburg soils have hue of 7.5YR or yellower in the Bt2 horizon. Carpenter soils are also well drained. Culleoka, Loudonville and Penn soils have bedrock at 20 to 40 inches. Hayter soils are well drained and have moderately rapid permeability. Lamotte soils contain sandstone fragments in the lower part of the solum in the Cr horizon. Legore, Myersville and Neshaminy soils have igneous rock fragments. Mechanicsburg soils have a lithologic discontinuity within 40 inches.
GEOGRAPHIC SETTING: Manassas soils are on footslopes, colluvial fans, along drainageways, and in narrow saddles of the Triassic lowlands in the Piedmont Province. Slopes range from 0 to 7 percent. The soils developed in colluvial and residual materials derived from dominantly shale, siltstone, and conglomerate. Mean annual temperature ranges from 52 degrees to 59 degrees F. Mean annual precipitation ranges from about 36 to 44 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing and
Penn soils and the
Klinesville soils. Bermudian soils do not have mottles within 40 inches of the soil surface. Klinesville soils have a solum less than 20 inches thick.
DRAINAGE AND PERMEABILITY: Moderately well drained and well drained; slow to medium runoff; moderate to moderately rapid permeability.
USE AND VEGETATION: Most of these soils have been cleared and are used for cultivated crops and pasture. Crops include corn, small grain and hay. Some areas are in woodland. Woodland vegetation is mostly oaks, hickory, yellow-poplar, sweet gum, dogwood and walnut.
DISTRIBUTION AND EXTENT: Virginia, Maryland, Pennsylvania and New Jersey; also possibly in North Carolina. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: RALEIGH, NORTH CAROLINA
SERIES ESTABLISHED: Loudoun County, Virginia; 1954.
REMARKS: This revision changes the classification from Typic Hapludults to Ultic Hapludalfs based on data from laboratory analysis of several pedons in Virginia.
Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon-zone from 0 to 16 inches (Ap and AB horizons)
2. Argillic horizon-zone from 16 to 30 inches (Bt horizons)
3. Base saturation between 35 and 60 percent at 60 inches
REVISED = 2/18/2004, MAV added active ce activity class.
REVISED = 8/12?2013, DTA added Lat. and Long.
National Cooperative Soil Survey