LOCATION BROAD CREEK             MD+NJ

Established Series
CEP/DCS
10/2022

BROAD CREEK 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: Moderately high to high
Parent Material: Fine-loamy, mixed estuarine deposits
Slope: 0 to 3 percent
Mean Annual Air Temperature: 55 degrees F. (13 degrees C)
Mean Annual Water Temperature: 53 degrees F. (12 degrees C)

TAXONOMIC CLASS: Fine-loamy, mixed, subactive, nonacid, mesic Fluventic Sulfiwassents

TYPICAL PEDON: Broad Creek loam on a permanently submerged tidal creek channel landform with less than 3 percent slope under 3.0 meters of estuarine water. (Colors are for moist soil unless otherwise stated).

Ase1--0 to 6 cm; black (N 2.5/) loam; massive; very fluid; slight hydrogen sulfide odor; ultra acid (pH 3.31), ultra acid (pH 2.88) after 16 weeks; color reaction with 3% hydrogen peroxide, slightly effervescent with 30% hydrogen peroxide; clear boundary.

Ase2--6 to 25 cm; black (N 2.5/) loam; massive; very fluid; slight hydrogen sulfide odor; very strongly acid (pH 4.7), ultra acid (pH 3.09) after 16 weeks; color reaction with 3% hydrogen peroxide, slightly effervescent with 30% hydrogen peroxide; clear boundary.

Ase3--25 to 42 cm; greenish black (10Y 2.5/1) silt loam; massive; very fluid; strongly acid (pH 5.11), ultra acid (pH 2.73) after 16 weeks; color reaction with 3% hydrogen peroxide, slightly effervescent with 30% hydrogen peroxide; clear boundary.

Cseg--42 to 68 cm; greenish black (5GY 2.5/1) clay loam; massive; very fluid; strongly acid (pH 5.47), ultra acid (pH 3.23) after 16 weeks; color reaction with 3% hydrogen peroxide, slightly effervescent with 30% hydrogen peroxide; clear boundary.

Aseb--68 to 96 cm; black (N 2.5/0) silty clay loam; massive; moderately fluid; slight hydrogen sulfide odor; moderately acid (pH 5.92), ultra acid (pH 3.17) after 16 weeks; color reaction with 3% peroxide hydrogen, slightly effervescent with 30% hydrogen peroxide; clear boundary.

C'seg--96 to 126 cm; dark greenish gray (5GY 3/1) silty clay; massive; slightly fluid; strongly acid (pH 5.39), extremely acid (pH 3.53) after 16 weeks; color reaction with 3% hydrogen peroxide, slightly effervescent with 30% hydrogen peroxide; clear boundary.

Cg--126 to 183 cm; dark greenish gray (10Y 3/1) silt loam; massive; slightly fluid; slightly acid (pH 6.49); 3% shell fragments by volume; no color reaction with 3% hydrogen peroxide, very slightly effervescent with 30% hydrogen peroxide.

TYPE LOCATION: Anne Arundel County, Maryland; South River, Broad Creek, approximately 1,900 feet north of Porter Point and approximately 2,300 feet south of South River Manor. USGS South River topographic quadrangle; latitude 38 degrees, 57 minutes, 51.80 seconds N. and 76 degrees, 34 minutes, 36.11 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 submerged
Depth to hyper-sulfidic materials (incubated pH 4.0): 0 to 50 centimeters
Manner of Failure / Fluidity Class: moderately to very fluid throughout; slightly fluid below 150cm
Shell Fragments: 0 to 5 percent, by volume, throughout
Soil reaction: Ultra Acid to moderately alkaline; oxidized reaction: ultra acid to moderately acid throughout
Electrical Conductivity: greater than 1.13 dS / m-1 by 1:5 by volume solution mixture

Glauconite ranges from 0 to 15% by weight in the fine-earth fraction.

RANGE OF INDIVIDUAL HORIZONS:
Ase or Aseg horizons:
Color - hue of N, 10Y, 5GY or 10GY; value of 2.5 or 3; and chroma of 0 or 1
Texture - loam, silt loam, or silty clay loam
Consistence - very fluid
Sulfurous odor and sulfidic materials are present.

Cseg horizons:
Color - hue of N, 10Y, 5GY, 10GY, or 5G; value of 2.5 or 3; and chroma of 0 or 1
Texture - loam, silt loam, clay loam, clay, silty clay loam, silty clay
Consistence - slightly fluid to very fluid
Aseb, Asegb, or ACsegb horizons:
Color - hue of N, 5Y, 5GY, 10GY; value of 2.5 or 3; and chroma of 0 or 1
Texture - fine sandy loam, sandy loam, loam, silty clay loam, silt loam
Consistence - moderately fluid
Sulfurous odor and sulfidic materials are present.
C'seg horizons (if present):
Color - hue of 10Y, 5GY or 10 GY; value of 2.5 or 3; and chroma of 1
Texture - loam, silt loam, silty clay loam, silty clay
Consistence - slightly fluid to moderately fluid
Sulfurous odor and sulfidic materials are present.

COMPETING SERIES:
Figgs soils - formed on lagoon bottom in fine-loamy estuarine lagoonal deposits, do not contain glauconite, located within the Northern Tidewater Area, MLRA 153D.
Hillsmere soils (tentative) - occur on Estuarine Channels and Mainland Cove landforms; do not contain buried A horizons.

GEOGRAPHIC SETTING:
Landscape: Northern Coastal Plain Estuaries
Landform: Estuarine Tidal Creek / Stream channels
Parent Material: Fine-loamy, mixed estuarine deposits
Slope: 0 to 1 percent
Mean Annual Air Temperature: 52 to 59 degrees F. (11 to 15 degrees C.)
Mean Annual Water Temperature: 50 to 60 degrees F. (10 to 16 degrees C.)
Water Depth Range: 3 to 16 feet (1 to 5 meters)
Water Regime: Tidal, 0 to 2 feet (0 to 0.6 meters) tidal range
Water Salinity Range: 3 to 25 ppt

GEOGRAPHICALLY ASSOCIATED SOILS:
Duvall Creek soils - occur on Wave-Built Terrace landforms; composed of Holocene sandy material.
Hillsmere soils - occur on Estuarine Channel and Mainland Cove landforms; composed of fine Holocene estuarine deposits.
Long Point soils - occur on Submerged Tidal Marsh landforms; composed of Holocene sandy material and hemic organic material overlying a relatively intact paleosol.
Overboard soils - occur on Tidal Creek Platform landforms; composed of Holocene fluid fine material overlying pre-Holocene Tertiary fluviomarine deposit materials.
South River soils - occur on Wave-Cut Platform landforms and composed of Holocene sandy material overlying Tertiary fluviomarine deposits that contain horizons with chroma 3 or more between 15 and 100 cm.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage Class: Subaqueous drainage
Saturated Hydraulic Conductivity: Moderately high to high
Soil Moisture Regime: Peraquic

Broad Creek soils are permanently submerged / continuously inundated with salt or brackish water. The presence of hypersulfidic 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.

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

DISTRIBUTION AND EXTENT: Northern Atlantic Coastal Plain sub-estuaries of the western portion of the Chesapeake Bay and Atlantic Seaboard estuaries of the Northern Coastal Plain in New Jersey. MLRA 149A. This series is of small extent.

SERIES ESTABLISHED: Anne Arundel County, Maryland, 2022.

REMARKS: This subaqueous series is named for Broad Creek in the South River sub-estuary of Chesapeake Bay. Areas of Broad Creek were formerly included with Water.

Diagnostic horizons and other diagnostic soil characteristics recognized in this pedon are (Keys to Soil Taxonomy, Twelfth Edition, 2012):
-Ochric epipedon-the zone from 0 to 42 centimeters (Ase horizons)
-Peraquic feature-the zone from 0 to 183 centimeters is permanently saturated
-Hyper-sulfidic materials-the zone from 0 to 126 centimeters incubated pH values less than 4.0 after 16 weeks.
-n Value greater than 0.7 - the zone from 0 to 183 centimeters with a slightly fluid to very fluid manner of failure.

ADDITIONAL DATA: Park, C.E., University of Maryland, Master of Science, 2021; thesis; Subaqueous Soils of South River, Maryland: Soil-Landscape Model Evaluation

Data Map Unit ID: 883181
NASIS user site and pedon ID: 2021MD003052

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National Cooperative Soil Survey
U.S.A.