LOCATION PURNELL                 MD+DE NJ

Established Series
JLB/Rev. JDK
08/2024

PURNELL SERIES

MLRA(s)--153C, 153D
Depth Class--Very deep
Drainage Class--Very poorly drained
Parent Material--Sandy eolian and marine deposits
Geomorphic location--Back-barrier tidal marshes
Slope--0 to 1 percent
Mean Annual Air Temperature--14 degrees C (57 degrees F)
Mean Annual Precipitation--1118 millimeters (44 inches).

TAXONOMIC CLASS: Sandy, mixed, mesic Histic-haplic Sulfaquents

TYPICAL PEDON: Purnell peat on a smooth 0 percent slope in a back-barrier salt marsh. (Colors are for a moist soil).

Oise--0 to 8 centimeters; dark brown (10YR 3/3) peat; fiber content is three-fourths soil volume after rubbing; 20 percent by weight mineral soil material; von Post value H3; many very fine and fine, and common coarse roots; neutral (pH 6.7), ultra acid (pH 3.1) oxidized pH; strongly saline (26 dS/m); abrupt smooth boundary. (0 to 32 centimeters thick)

Oese--8 to 33 centimeters; very dark grayish brown (2.5Y 3/2) mucky peat; fiber content is one-half soil volume after rubbing; von Post value H5; many very fine and fine, and few coarse roots; neutral (pH 7.2), strongly acid (pH 5.4) oxidized pH; strongly saline (19 dS/m); abrupt smooth boundary. (8 to 40 centimeters thick)

Cseg1--33 to 46 centimeters; dark gray (5Y 4/1) sand; single grain; loose; non-fluid; common fine roots; slightly alkaline (pH 7.4), extremely acid (pH 3.5) oxidized pH; strongly saline (26 dS/m); clear wavy boundary. (13 to 76 centimeters thick)

Cseg2--46 to 102 centimeters; gray (5Y 6/1) sand; single grain; loose; non-fluid; common, medium, faint gray (2.5Y 5/1) areas of iron depletion; neutral (pH 7.2), extremely acid (pH 3.9) oxidized pH; strongly saline (22 dS/m); gradual wavy boundary. (51 to 76 centimeters thick)

Cseg3--102 to 200 centimeters; gray (5Y 5/1) sand; non-fluid; single grain; loose; non-fluid; neutral (pH 7.3), extremely acid (pH 3.9) oxidized pH; strongly saline (22 dS/m).

TYPE LOCATION: Worcester County Maryland in Assateague State Park. Approximately 385 meters (1263 feet) west of the intersection of Campground Road and the northern entrance to Loop B and approximately 736 meters (2,415 feet) southwest of the road intersections of Route 611 and Stephen Decatur Memorial Road in a tidal marsh. USGS topographic quadrangle: Tingles Island, MD.

Latitude--38.2333333
Longitude-- -75.1444444
Datum--WGS84
Coordinate source--Unknown

RANGE IN CHARACTERISTICS:
Thickness of organic surface layer--20 to less than 40 centimeters
Electrical Conductivity--Greater than 8 dS/m (5.6 ppt)
Soil Reaction--Neutral to slightly alkaline (pH 6.6 to 7.8)
Oxidized Reaction--Ultra-acid to extremely acid (pH <3.5 to 4.4)
Depth to hypersulfidic materials (oxidized pH 4.0 or less)--0 to 50 centimeters
Total Soil Organic Carbon Stock 0 to 100 centimeters--13 to 21 kg m-2
Total Soil Organic Carbon Stock 0 to 200 centimeters--17 to 25 kg m-2
Manner of failure / fluidity class--Nonfluid throughout the mineral horizons
Other Features--Some pedons may contain sapric soil materials depending on the degree of decomposition. Buried surface horizons may exist in areas closer to the dunes and areas of known storm washover events.

Oise horizons, where present:
Hue--7.5YR to 2.5Y
Value--2 to 4
Chroma--1 to 3
Texture--Peat
Von Post humification scale--Typically H3
Organic carbon density--20 to 54 kg m-3

Oese horizons:
Hue--10YR to 5Y
Value--2 or 3
Chroma--1 to 3
Texture--Mucky peat
Von Post humification scale--H4 to H6
Organic carbon density--24 to 122 kg m-3

Aseg horizon, where present:
Hue--10YR to 10Y
Value--2.5 to 4
Chroma--1 or 2
Texture--Sand, loamy sand, sandy loam, loam, or silt loam
Organic carbon density--12 to 47 kg m-3

Cseg horizons:
Hue--10YR to 5GY and neutral
Value--4 to 6
Chroma--0 to 2
Texture--Sand, coarse sand, or loamy sand
Organic carbon density--12 to 47 kg m-3

COMPETING SERIES: There are no known competing series in the same family.

GEOGRAPHIC SETTING:
Parent Material--Sandy eolian and marine deposits
Landscape--Barrier islands
Landform--Back-barrier tidal salt marshes and marshes near ocean coastal inlets.
Elevation--0 to 1 meters
Mean Annual Air Temperature--11 to 14 degrees C (52 to 57 degrees F)
Mean Annual Precipitation--965 to 1219 millimeters (38 to 48 inches)
Frost Free Period--175 to 200 days

GEOGRAPHICALLY ASSOCIATED SOILS:
These are the Brockatonorton, Fox Hill, Pawcatuck, Saltpond, and Transquaking soils.
Brockatonorton soils--do not have a histic epipedon, are moderately well drained, and formed on back dunes of barrier islands.
Fox Hill soils--do not have a histic epipedon, are poorly drained, and are slightly higher on the landscape on interdune swales of barrier islands.
Pawcatuck soils--Have 40 to 130 centimeters of organic soil materials underlain by sandy mineral material, and often occur closer to the marsh-lagoon interface.
Saltpond soils--Have less than 20 centimeters of organic soil materials (and therefore do not have histic epipedons), are underlain by sandy mineral material, and are commonly intermingled with Purnell soils.
Transquaking soils--Have greater than 130 centimeters of organic soil materials and occur at slightly lower elevations in the marsh.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage Class--Very poorly drained
Saturated Hydraulic Conductivity--High to very high in the organic deposits and very high in the sandy substratum
Soil moisture regime--Peraquic
Flooding-very frequent, very brief (Flooded by tidal waters twice daily and during significant coastal storm events)

USE AND VEGETATION:
Major Uses--Purnell soils are used mainly as wetland wildlife habitat. Areas of this soil act as a protective barrier to residential communities on the barrier islands. This soil sequesters relatively less amounts of carbon compared to other local tidal salt marsh geographically associated soils.
Natural Vegetation--Saltmarsh cordgrass (Spartina alterniflora), saltmeadow cordgrass (Spartina patens), saltgrass (Distichlis spicata), glasswort (Salicornia bigelovii), sea lavender (Limonium carolinianum), and black needlerush (Juncus roemerianus).

DISTRIBUTION AND EXTENT:
General area--Barrier-island tidal salt marshes in the Coastal Plain of Maryland, Delaware, and New Jersey
Land Resource Regions--T - Atlantic and Gulf Coast Lowland Forest and Crop Region
MLRA(s)--153C, 153D
Extent--Small

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Special Projects Region

SERIES ESTABLISHED: Worcester County, Maryland, 1995.

REMARKS: These soils were formerly included in the Tidal Marsh miscellaneous areas. They become extremely to ultra-acid when drained.

Diagnostic horizons and features recognized in this pedon are:
Histic epipedon--the zone between 0 and 33 centimeters (Oise and Oese horizons)
Fibric soil material--the zone between 0 and 8 centimeters (Oise horizon)
Hemic soil material--the zone between 8 and 33 (Oese horizon)
Sulfidic materials--the zone from 0 to 8 centimeters and 33 to 50 centimeters (Oise, Cseg1, and Cseg2 horizons).

ADDITIONAL DATA:
Some morphological and laboratory data used in this OSD were obtained from: Kim, J.D. 2022. M.S. Thesis. Distribution And Variability of Carbon Stocks in Mid-Atlantic Tidal Marsh Soils. University of Maryland, College Park, MD.

Incubated pH values were obtained from S2016DE005001, which has very similar characteristics as the typical pedon.

NASIS User Pedon ID--2012MD047043
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National Cooperative Soil Survey
U.S.A.