LOCATION SUNKEN MDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Typic Endoaqualfs
TYPICAL PEDON: Sunken mucky silt loam on a smooth 0 percent slope in a submerging upland (Colors are for a moist soil.)
Oi--0 to 2 inches; dark reddish brown (5YR 2.5/2) peat, fibric soil material dominantly composed of pine needles; fiber content is three-fourths of the soil volume after rubbing; 10 percent mineral soil material; many fine, medium, and coarse live roots; neutral; clear smooth boundary. (1 to 4 inches thick)
Oa--2 to 4 inches; very dark brown (10YR 2/2) muck, sapric soil material; fiber content is one-tenth of the soil volume after rubbing; 10 percent mineral soil material; common fine and medium live roots; neutral; clear smooth boundary. (0 to 6 inches thick)
Ag--4 to 6 inches; grayish brown (10YR 5/2) silt loam; massive; friable, slightly sticky, slightly plastic; common very fine and fine, few medium roots; common fine and few medium pores; neutral; clear smooth boundary. (2 to 8 inches thick)
Eg--6 to 18 inches; light gray (10YR 6/1) silt loam, massive; friable, sticky, plastic; common very fine, fine, and medium roots; common fine and few medium and very fine pores; common medium prominent yellowish red (5YR 5/8) soft masses of iron accumulations; neutral; gradual wavy boundary. (8 to 14 inches thick)
Btg1--18 to 38 inches; light gray (10YR 6/1) silty clay loam, mottles; massive; firm, sticky, plastic; few medium and fine roots; common fine and few medium pores; few faint clay films on faces of peds; common medium prominent strong brown (7.5YR 5/8) and common medium distinct brownish yellow (10YR 6/8) masses of iron accumulations; slightly acid; gradual wavy boundary. (15 to 29 inches thick)
2Btg2--38 to 65 inches; gray (5Y 6/1) very fine sandy loam, massive; firm, slightly sticky, plastic; common fine and very fine pores; few faint clay films on faces of peds; common medium prominent brownish yellow (10YR 6/8) masses of iron accumulations; moderately acid; gradual smooth boundary. ( 17 to 30 inches thick)
2Cg--65 to 72 inches; light olive gray (5Y 6/2) fine sand, massive; common coarse distinct yellowish brown (10YR 5/6) masses of iron accumulations; slightly acid.
TYPE LOCATION: Dorchester County, Maryland; approximately 2 miles north of Golden Hill, 2,000 feet northeast of Beaverdam Creek and Smithville Road, 900 feet east of Smithville Road; Latitude 38 degrees 25 minutes 54 seconds north, Longitude 76 degrees 13 minutes 58 seconds west.
RANGE IN CHARACTERISTICS: Thickness of the organic deposits ranges from 2 to 8 inches. The soil is moderately acid to neutral below 18 inches in the natural state. Above 18 inches reaction ranges from strongly acid to neutral. It can range from extremely acid through strongly acid upon drying. Total sulfur content of the organic horizons ranges from 0.50 percent to 1.5 percent. Total sulfur content of the mineral horizons ranges from 0.05 percent to 0.50 percent. Conductivity of the saturation extract of the organic horizons is greater than 8 mmhos and ranges from 2 to 8 mmhos in the mineral horizons. Mineral horizons typically have n values less than 0.7 but may range up to 1.0. Structure and clay films are faint or not visible at all in the subsoil because of the clay being dispersed due to the presence of soluble salts.
The organic surface layers have hue of 5YR and 10YR, value of 2 or 3, and chroma of 2 through 4. It is typically fibric and sapric but includes hemic soil materials. The fiber content after rubbing is greater than one-tenth of the soil volume. Mineral material content ranges from 5 to 40 percent.
The Ag horizon has hue of 10YR and 2.5Y, value of 4 through 6, and chroma of 1 or 2. It is silt loam.
The Eg horizon has hue of 10YR and 2.5Y, value of 5 or 6, and chroma of 1 or 2. It is silt loam.
The Btg horizon has hue of 10YR and 2.5Y, value of 5 or 6, and chroma of 1 or 2. Texture ranges from silt loam to silty clay loam.
The 2Btg horizon has hue of 10YR through 5Y, value of 5 through 7, and chroma of 1 or 2. It is fine sandy loam to very fine sandy loam.
The 2Cg horizon has hue of 10YR through 5Y, value of 5 through 7, and chroma of 1 or 2. It ranges from fine sand to loamy sand.
COMPETING SERIES: These are the Blanchester, Racoon, Sebring, and Whitson series in the same family; and the Dasher, Deweyville, Elkton, Othello, and Toddstav series in related families. Blanchester soils have 2 to 10 percent coarse fragments in the lower part of the solum. Racoon soils have an E horizon 14 to 26 inches thick. Sebring soils have a degraded BE horizon and stratified material in the C horizon. The Whitson soils formed in calcareous materials. Dasher and Deweyville soils have thermic temperature regimes. All of the above soils have a water table below the soil surface. Elkton, Othello, and Toddstav soils have a base saturation less than 35 percent 49 inches below the upper boundary of the argillic horizon. All of the competing soils lack the presence of sulfur and soluble salts.
GEOGRAPHIC SETTING: Sunken soils are located in brackish submerging uplands along tidally-influenced bays, rivers, and drainageways of the Mid-Atlantic Coastal Plain. They formed dominantly in loamy eolian or alluvial deposits overlying unconsolidated sandy alluvial and marine sediments. Gradual submergence and a high water table, has allowed the intrusion of salt tolerant plants, leading to the development of distinct organic horizons. Slopes range from 0 to 1 percent. Mean annual temperature ranges from 54 to 58 degrees F., and mean annual precipitation ranges from 42 to 48 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bestpitch, Elkton, Honga, Othello, and Transquaking soils. Bestpitch, Honga, and Transquaking soils are Histosols on estuarine and submerged upland tidal marshes next to major drainageways. Elkton and Othello are mineral soils on adjacent upland areas at slightly higher elevations.
DRAINAGE AND PERMEABILITY: Very poorly drained. Runoff is very slow to ponded. Permeability is slow. These soils are flooded by brackish waters during seasonally and storm induced tidal events.
USE AND VEGETATION: Sunken soils are used mainly as wetland wildlife habitat. Dominant vegetation is stunted loblolly pine (Pinus taeda), saltmeadow cordgrass (Spartina patens), saltgrass (Distichlis spicata), marsh-elder (Iva frutescens), poison ivy (Rhus radicans), and groundsel-tree (Baccharis halimifolia).
DISTRIBUTION AND EXTENT: Coastal Plain of Maryland and Delaware. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Dorchester County, Maryland, 1992. The name is coined.
REMARKS: 1. This soil was previously included in the tidal marsh and swamp miscellaneous areas; and in the Elkton and Othello soil series as inclusions in the low phase map units. 2. These soils become extremely acid when drained. 3. Diagnostic horizons and features recognized in this pedon are:
a. total sulfur content - ranges from 0.50 to 1.50 percent in the organic zone, and from 0.05 to 0.50 percent in the mineral horizons. b. salt content - the conductivity of the saturation extract ranges from 2 to 8 mmhos in the mineral horizons, and is greater than 8 mmhos in the organic zone.
c. argillic horizon - the zone from 18 to 65 inches (Btg and 2Btg horizons) d. base saturation - is greater than 35 percent 49 inches below the upper boundary of the argillic horizon.
e. surface texture - mucky silt loam from mixture of Oa and Ag horizons. Dry colors and thickness prevent this layer from being umbric or mollic.
f. structureless - the original structure of this soil has been destroyed because of dispersion due to salts.
ADDITIONAL DATA: Refer to publication "Tidal Marsh Soils of Maryland", Darmody, R.G. and Foss, J.E., Maryland Agricultural Experiment Station Publication MP 930, October 1978.
TABULAR SERIES DATA:
SOI-5 Soil Name Slope Airtemp FrFr/Seas Precip Elevation MD0143 SUNKEN 0- 1 54- 58 190-210 42- 48 0- 2SOI-5 FloodL FloodH Watertable Kind Months Bedrock Hardness MD0143 OCCAS 0- 0 APPARENT JAN-DEC 60-60
SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC- MD0143 0- 6 MK-SIL 0- 0 100-100 15-20 10- 30 MD0143 6-18 SIL 0- 0 100-100 15-25 5- 20 MD0143 18-38 SICL SIL 0- 0 100-100 18-35 5- 20 MD0143 38-65 VFSL FSL 0- 0 100-100 10-20 5- 20 MD0143 65-72 FS LFS LS 0- 0 100-100 1- 5 5- 20
SOI-5 Depth -pH- O.M. Salin Permeab Shnk-Swll MD0143 0- 6 5.1- 7.3 10-15 8-32 2.0- 6.0 LOW MD0143 6-18 5.1- 7.3 1.-3. 2- 8 0.2- 2.0 LOW MD0143 18-38 5.6- 7.3 0.-.5 2- 8 0.06- 0.2 LOW MD0143 38-65 5.6- 7.3 0.-.5 2- 8 0.6- 2.0 LOW MD0143 65-72 5.6- 7.3 0.-.5 2- 8 2.0- 20 LOW