LOCATION GROSSTOWN               MD

Established Series
EHE-SLD-DPRV/Rev. JWB
11/2015

GROSSTOWN SERIES

MLRA(s): 149A (Northern Coastal Plain)
Depth Class: Very deep
Drainage Class (Agricultural): Well
Saturated Hydraulic Conductivity Class:
Landscape: Coastal Plain, upland
Parent Material: Gravelly fluviomarine sediments
Slope: 0 to 40 percent
Mean Annual Air Temperature (type location): 13 degrees C. (56 degrees F.)
Mean Annual Precipitation (type location): 1067 mm (42 inches )

TAXONOMIC CLASS: Coarse-loamy, mixed, semiactive, mesic Typic Hapludults

TYPICAL PEDON: Grosstown silt loam, at the edge of an active gravel pit, in a power-line right-of-way. (Colors are for moist soil unless otherwise indicated.)

Ap--0 to 10 cm (0 to 4 inches); brown (10YR 4/3) gravelly silt loam; pale brown (10YR 6/3) dry; weak medium subangular blocky structure; very friable; non sticky, non plastic; many very fine and fine, and common medium and coarse roots; common medium tubular pores; 20 percent quartzite gravel; extremely acid; clear wavy boundary. (5 to 38 cm thick)

Bt1--10 to 51 cm (4 to 20 inches); yellowish brown (10YR 5/4) silt loam; weak medium and coarse subangular blocky structure; very friable; slightly sticky, slightly plastic; few very fine, fine, medium and coarse roots; few faint patchy yellowish brown (10YR 5/4) clay films on faces of peds; 3 percent mixed gravels; extremely acid; gradual wavy boundary.

Bt2--51 to 66 cm (20 to 26 inches); strong brown (7.5YR 4/6) gravelly loam; weak coarse subangular blocky structure; very friable; slightly sticky, slightly plastic; few very fine roots; common medium tubular and vesicular pores; many distinct strong brown (7.5YR 4/6) clay films on faces of peds, on gravels, and clay bridging between sand grains; common coarse yellowish brown (10YR 5/4) iron depletions; 25 percent mixed gravels; very strongly acid; clear wavy boundary. (Combined thickness of the Bt horizon is 38 to 112 cm)

2Bt3--66 to 183 cm (26 to 72 inches); brown (7.5YR 4/4) extremely gravelly silt loam; weak coarse prismatic structure; moist consistence varies from loose to very firm; non sticky, non plastic; excavation is difficult when dry, and moderately difficult when moist; very few fine roots in upper 10 cm (4 inches) of horizon; few medium vesicular pores; many discontinuous prominent brown (7.5YR 5/4) clay films on gravels; few fine platy dark reddish brown (2.5YR 3/3) ferriargillans; 62 percent mixed gravels; trace of cobbles; very strongly acid.

TYPE LOCATION: Charles County, Maryland, USGS Hughesville topographic quadrangle; latitude 38 degrees, 32 minutes, 48.57 seconds North and longitude 76 degrees, 46 minutes, 42.75 seconds West, NAD 1983.

RANGE IN CHARACTERISTICS:
Depth to the top of the Argillic horizon: 8 to 51 cm (3 to 20 inches)
Depth to the base of the Argillic horizon: 64 (25 inches) to greater than 183 cm (72 inches)
Depth to Bedrock: Greater than 183 cm (72 inches)
Depth to Seasonal High Water Table: greater than 183 cm (72 inches), January to December
Depth to Lithologic Discontinuity: 43 to 107 cm (17 to 42 inches)
Rock Fragment content: 0 to 34 percent, by volume, in the A, E and upper B horizons, 30 to 80 percent in the lower subsoil, 50 to 90 percent in the substratum. If a second discontinuity is present in the lower substratum, gravel content drops to less than 15 percent and fine and very fine sands dominate the sand fraction. .
Other features: the A, E and upper Bt horizons have greater than 30 percent silt
Soil Reaction: extremely acid, except where limed

RANGE OF INDIVIDUAL HORIZONS:
A or Ap horizon:
Color--hue of 7.5YR to 2.5Y, value of 2 to 5 and chroma of 1 to 4. Horizons with value of 3 or less are less than 20 cm (8 inches) thick.
Texture (fine-earth fraction)--sandy loam, fine sandy loam, loam or silt loam.

E, or BE (if it occurs):
Color--hue of 10YR or 2.5Y, value of 4 to 6 and chroma of 3 to 6.
Texture (fine-earth fraction)--loam, sandy loam, fine sandy loam or silt loam

Bt horizon:
Color--hue of 7.5YR to 2.5Y, value of 4 to 6 and chroma of 3 to 8.
Texture (fine-earth fraction)--the upper Bt is loam, silt loam, or fine sandy loam and may have thin layers of clay loam; the lower Bt is sandy loam or silt loam and may have thin layers of sandy clay loam.
Other features--iron masses in shades of red, yellow or brown, and iron depletions in shades of pale brown, yellow or olive may be present, thin platy ferriargillans in shades of black to dusky red are present in many pedons. Iron-Manganese coatings in shades of black or dusky red are also present on gravel in many pedons.

2Bt horizon:
Color--hue of 7.5YR or 10YR, value of 5 or 6 and chroma of 3 to 6.
Texture (fine earth fraction)--silt loam, loam, fine sandy loam or loamy fine sand

BC or 2BC horizon (if it occurs):
Color--hue of 5YR to 10YR, value of 4 to 6 and chroma of 2 to 8.
Texture (fine-earth fraction)--coarse sand, loamy coarse sand, sand, loamy sand, sandy loam or loam.

C or 2C horizon (if it occurs):
Color--hue of 7.5YR or 10YR, value of 5 or 6 and chroma of 3 to 6.
Texture (fine-earth fraction)--loamy sand, sandy loam, fine sandy loam or loam.

COMPETING SERIES:
Adyeville soils--moderately deep; formed in residuum from interbedded sandstone, siltstone, and shale
Greenwich soils--fewer gravels in the lower part of the solum and the substratum
Swedesboro soils--more sand, lower silt content; contains 1 to 10 percent glauconite pellets in the solum
Unicorn soils--fewer gravels in the lower part of the solum and the substratum

Similar soils
Dennisville soils--more sand, lower silt content; fewer gravels in the lower solum and the substratum; moderately rapid to rapid permeability
Downer soils--more sand, lower silt content; fewer gravels in the lower solum and the substratum
Ingleside soils--more sand, lower silt content; fewer gravels in the lower solum and the substratum
Phalanx soils--petroferric contact within a depth of 102 cm (40 inches)
Swainton soils--more sand, lower silt content; moderately rapid permeability
Woodmansie soils--more sand, lower silt content

GEOGRAPHIC SETTING:
Landscape: Coastal plain, upland
Landform: Broad interstream divide
Hillslope Profile Position: Summits, shoulders, upper backslopes
Geomorphic Component: Interfluve, side slope, terrace tread
Parent Material: gravelly fluviomarine sediments
Slope: 0 to 40 percent
Elevation: 3 to 122 meters (10 to 400 feet)
Frost-free Period: 180 to 210 days
Mean Annual Air Temperature: 11 to 14 degrees C. (52 to 57 degrees F.)
Mean Annual Precipitation: 1016 to 1270 mm (40 to 50 inches)

GEOGRAPHICALLY ASSOCIATED SOILS:
Beltsville soils--moderately well drained, with a seasonal high water table between 51 and 102 cm (20 and 40 inches), have a fragipan; on higher landscape positions
Evesboro soils--sandy throughout and excessively drained
Hoghole soils--sandy-skeletal subsoil and excessively drained
Marr soils--dominantly fine and very fine sand in the sand fraction, lack gravel in the subsoil; on lower side slopes
Westphalia soils--dominantly fine and very fine sand in the sand fraction, lack gravel in the subsoil; on lower side slopes

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class (Agricultural): Well drained
Internal Free Water Occurrence: Very deep
Flooding Frequency and Duration Classes: None
Ponding Frequency and Duration Classes: None
Index Surface Runoff Class: Negligible to high
Saturated Hydraulic Conductivity Class: Moderately high to high
Permeability Class (obsolete): Moderate
Shrink-swell Potential Class: Low

USE AND VEGETATION:
Major Uses: Woodland and urban.
Dominant Vegetation: Where cultivated--corn, soybeans, and hay land. Where wooded--mixed upland hardwoods, chiefly red and white oaks, beech, holly; and Virginia and shortleaf pines

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: RALEIGH, NORTH CAROLINA
Distribution: Coastal plain of southern Maryland and possibly parts of Delaware and New Jersey
Extent: The series is of small extent, but locally significant.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia

SERIES ESTABLISHED: Charles County, Maryland, 2007

REMARKS: Grosstown soils were previously mapped as Aura, Chillum, Croom and Sassafras soils, and were also mapped as miscellaneous land types.
Diagnostic horizons and soil characteristics recognized in this pedon are:
Ochric epipedon--the zone from 0 to 10 cm (Ap horizon)
Argillic horizon--the zone from 10 to 183 cm (Bt horizons)
Particle size control section--the zone from 10 to 61 cm
Lithologic Discontinuity-abrupt change in fine and coarse silt, and gravel content at 66 cm (2Bt3 horizon)
Series control section--the zone from 0 to 200 cm

Laboratory data indicates a base saturation (by sum of cations) of greater than 35 percent in the type location pedon. The high base status in this soil is thought to be the result of long-time cropping practices (liming) and not from the presence of native base cations. This soil will revert back to a lower base status if a liming schedule is not maintained.

ADDITIONAL DATA: Characterization data for this pedon (S01MD017-014) is available from the NSSL.

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National Cooperative Soil Survey
U.S.A.