LOCATION SELLMAN                 MD

Established Series
BMW/RBT
04/2021

SELLMAN SERIES

MLRA(s): 149A
Soil Survey Regional Office (SSRO) Responsible: Raleigh, North Carolina
Depth Class: Very deep
Drainage Class: Subaqueous (permanently submersed / continuously inundated)
Saturated Hydraulic Conductivity: Low to moderately low
Parent Material: Fine, glauconitic estuarine deposits
Slope: 0 to 3 percent
Mean Annual Air Temperature: 57 degrees F. (14 degrees C.)
Mean Annual Water Temperature: 57 degrees F. (14 degrees C)

TAXONOMIC CLASS: Fine, glauconitic, nonacid, mesic Sulfic Hydrowassents

TYPICAL PEDON: Sellman silty clay loam on a south flowing estuarine channel with less than 1 percent slope under 3.3 m of estuarine water. (Colors are for moist soil unless otherwise stated).

Ase -- 0 to 22 cm; greenish black (10Y 2.5/1) silty clay loam; massive; very fluid; 4 percent shell fragments; moderately alkaline (pH 8.0), moderately acid (pH 5.8) after 16 weeks; color reaction with 3% hydrogen peroxide, violently effervescent with 30% hydrogen peroxide, gradual boundary.

Cse1 -- 22 to 64 cm; greenish black (10Y 2.5/1) silty clay; massive; moderately fluid; strongly alkaline (pH 8.5), neutral (pH 6.6) after 16 weeks; color reaction with 3% hydrogen peroxide, violently effervescent with 30% hydrogen peroxide, gradual boundary.

Cse2 -- 64 to 88 cm; very dark greenish gray (10Y 3/1) silty clay; massive; very fluid; strongly alkaline (pH 8.5), slightly acid (pH 6.5) after 16 weeks; color reaction with 3% hydrogen peroxide, violently effervescent with 30% hydrogen peroxide, gradual boundary.

Cse3 -- 88 to 129 cm; very dark greenish gray (10Y 3/1) silty clay; massive; very fluid; moderately alkaline (pH 8.3), extremely acid (pH 4.3) after 16 weeks; no reaction with 3% hydrogen peroxide, strongly effervescent with 30% hydrogen peroxide, gradual boundary.

Cse4 -- 129 to 163 cm; very dark greenish gray (5GY 3/1) silty clay; massive; very fluid; moderately alkaline (pH 8.3), moderately acid (pH 5.6) after 16 weeks; no reaction with 3% hydrogen peroxide, strongly effervescent with 30% hydrogen peroxide.

TYPE LOCATION: Anne Arundel County, Maryland; Rhode River, approximately 1,770 feet south of Locust Point and 1,305 feet north of Sand Point. USGS South River topographic quadrangle; latitude 38 degrees, 52 minutes, 33.83 seconds N. and longitude 76 degrees, 31 minutes, 19.28 seconds W., WGS 1984; Major Land Resource Area 149A.

RANGE IN CHARACTERISTICS:
Depth to bedrock: Greater than 200 centimeters.
Depth to seasonal high water table: Permanently submersed
Shell Fragments: 0 to 2 percent, by volume, throughout
Soil reaction: Neutral to strongly alkaline; oxidized reaction: extremely acid to neutral
Depth to hyper-sulfidic materials (incubated pH 4.0): Greater than 100 centimeters
Depth to hypo-sulfidic materials: 0 to 50 centimeters
Manner of Failure / Fluidity Class: moderately to very fluid throughout
Salinity range is 7 to 15 (ppt).
Tidal range is 27 cm.
Water depth is 0 to 450 cm.

Occasionally horizons may qualify as sulfidic materials.
Range of Individual Horizons:

Ase horizon:
Color - hue 10Y or 5GY, value of 2.5 or 3, and chroma 0 to 1.
Texture - silty clay loam through loam
Consistence - very fluid

Cse horizon:
Color - hue 10Y or 5GY, value of 2.5 or 3, and chroma of 0 to 1.
Texture - silty clay, silty clay loam, or clay loam
Consistence - moderately fluid to very fluid

COMPETING SERIES: None

GEOGRAPHIC SETTING:
Landscape: Northern Coastal Plain estuaries
Landform: Estuarine channels, estuarine tidal creek channels, and mainland coves
Parent Material: Fine, glauconitic estuarine deposits
Slope: 0 to 3 percent
Mean Annual Air Temperature: 50 to 57 degrees F. (10 to 14 degrees C.)
Mean Annual Water Temperature: 52 to 58 degrees F. (11 to 14 degrees C.)
Water Depth Range: 0 to 14.8 feet (0 to 4.5 meters)
Water Regime: Tidal, 0 to 1 foot (0 to 0.3 meters) tidal range
Water Salinity Range: 7 to 15 ppt

GEOGRAPHICALLY ASSOCIATED SOILS:
Coards soils-contain sulfidic materials within 50 cm of the soil surface and occur in MLRA 153D in coastal bays and lagoons with higher salinity ranges.
Contees Wharf soils (proposed)-occur on similar landforms but have a fine-silty particle size family class.
Rhode River soils (proposed)-occur on wave-cut platforms, saddles and shoals and have pre-Holocene materials within 100 cm of the soil surface.
Sand Point soils (proposed)--have sandy surface horizons and hyper-sulfidic materials within 100 centimeters of the soil surface.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage Class: Subaqueous and peraquic soil moisture regime
Saturated Hydraulic Conductivity: Low to moderately low
Soil is permanently submerged / continuously inundated with brackish water. The presence of hypo-sulfidic materials within 50 cm of the soil surface puts these soils at risk for potential acid sulfate soil formation if they are dredged and exposed to the air.

USE AND VEGETATION:
Major Uses: Areas of this soil are used for recreational fishing, swimming, and boating. Commercial uses include shell fishing and aquaculture.
Dominant Vegetation: Benthic fauna such as clams, blue crabs, and oysters are associated with this soil. Eelgrass (Zostera marina), sea lettuce (Ulva sp.), and horned pondweed (Zannichellia palustris) may occur on these soils.

DISTRIBUTION AND EXTENT: Northern Atlantic Coastal Plain estuaries of the western portion of Chesapeake Bay. MLRA 149A. This series is of small extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Raleigh, North Carolina.

SERIES ESTABLISHED: Anne Arundel County, Maryland, 2018.

REMARKS: This subaqueous series is named for Sellman Creek, which is a tributary to the Rhode River sub-estuary of Chesapeake Bay. Areas of Sellman soils were formerly included with water.

Diagnostic horizons and other diagnostic soil characteristics recognized in this pedon are:
Ochric epipedon-the zone from 0 to 22 centimeters (Ase horizon)
Peraquic feature-the zone from 0 to 163 centerimeters is permanently saturated
Hypo-sulfidic materials-the zone from 0 to 163 centimeters

ADDITIONAL DATA:
NASIS Data Map Unit ID: 800963
NASIS user site and pedon ID: S2015MD003067.
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National Cooperative Soil Survey
U.S.A.