LOCATION
Tentative series
Rev. DAS/SJM
4/07
WAMPHASSUC SERIES
The Wamphassuc series consists of very deep, subaqueous soils that are permanently submerged in stream valleys and terraces. The Wamphassuc soils are formed in loamy marine sediments. Slope ranges from 0 to 2 percent, mean annual air temperature is about 10 degrees C., and mean annual precipitation is about 1142 mm.
TAXONOMIC CLASS: Coarse-loamy, mixed, active, nonacid, mesic Haplic Sulfaquents.
TYPICAL PEDON: Wamphassuc mucky silt loam on a north facing, nearly level slope in a submerged stream valley under 0.6 m of estuarine water (Colors are for moist soil).
Ag10 to 15 cm; black (10YR 2/1) mucky silt loam;
massive; very friable, nonsticky, nonplastic, very fluid; about 90 percent
mineral content; sulphurous odor; strongly saline (24 ppt); neutral (pH 7.1); extremely
acid (pH 4.4) after 8 weeks; gradual boundary.
ACg115 to 27 cm; black (10YR 2/1) mucky silt loam; massive; very friable, nonsticky, nonplastic, very fluid; 2 percent herbaceous fibers, 0 percent rubbed; sulphurous odor; strongly saline (23 ppt); slightly alkaline (pH 7.4); extremely acid (pH 4.3) after 8 weeks; gradual boundary.
ACg227 to 39 cm; greenish black (5GY 2.1/1) mucky silt loam; massive; very friable, nonsticky, nonplastic, very fluid; sulphurous odor; strongly saline (29 ppt); slightly alkaline (pH 7.6); extremely acid (pH 4.1) after 8 weeks; clear boundary.
Cg139 to 78 cm; very dark greenish gray (10Y 3/1) silt loam; massive; friable, nonsticky, nonplastic, nonfluid; 5 percent herbaceous fibers, 0 percent rubbed; 1 percent gravels; sulphurous odor; strongly saline (20 ppt); neutral (pH 7.3); extremely acid (pH 3.8) after 8 weeks; abrupt boundary.
Cg278 to 91 cm; very dark brown (10YR 2/1) sandy loam; massive; friable, nonsticky, nonplastic, nonfluid; 15 percent herbaceous fibers, 0 percent rubbed; 1 percent gravels; sulphurous odor; strongly saline (26 ppt); neutral (pH 7.2); extremely acid (pH 3.7) after 8 weeks; clear boundary.
Cg391 to 112 cm; very dark brown (10YR 2/1) fine sandy loam; massive; friable, nonsticky, nonplastic, nonfluid; 10 percent herbaceous fibers, 0 percent rubbed; strongly saline (20 ppt); neutral (pH 7.1); extremely acid (pH 4.3) after 8 weeks; clear boundary.
Cg4112 to 122 cm; black (2.5Y 2.5/1) sandy loam; massive; friable, nonsticky, nonplastic, nonfluid; 5 percent herbaceous fibers, 0 percent rubbed; strongly saline (27 ppt); neutral (pH 7.1); extremely acid (pH 4.3) after 8 weeks; clear boundary.
2Cg122 to 140 cm; black (7.5YR 2.5/1) gravelly loamy coarse sand; single grain; loose; nonsticky, nonplastic, nonfluid; 16 percent gravels; strongly saline (18 ppt); neutral (pH 7.1); extremely acid (pH 3.6) after 8 weeks.
TYPE LOCATION: Washington County, Rhode Island; located about 1100 feet northwest of the intersection of Palmer Neck Road and Providence and Worchester Railroad tracks, inside Wequetequock Cove, USGS Watch Hill topographic quadrangle; lat. 41 degrees 20 minutes 58 seconds N. and long. 71 degrees 52 minutes 56 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: The soils are permanently submerged. All
horizons have a pH of strongly acid through moderately alkaline and ultra acid through
very strongly acid after 8 weeks incubation. One or more horizons within 50 cm
have a pH of 4.0 or less after 8 weeks incubation. Electrical conductivity is
>16 mmhos/cm and salinity is >18 ppt (strongly saline) throughout the
profile.
The Ag and ACg horizon has hue of N, 10Y, 5Y, 2.5Y, and 10YR, value of 2 or 3, chroma of 0 or 1. Texture is mucky silt loam or silt loam. Consistence is very fluid. Organic matter is 5 to 15 percent. Sulphurous odor is present.
The Cg horizon has hues of N, 10YR, 2.5Y, 5Y, or 5GY, value of 2 through 5, and chroma of 0 through 2. Textures are mucky silt loam through sandy loam along with gravelly analogs. Consistence is slightly fluid through nonfluid. Gravel content is 0 to 25 percent.
The 2Cg and 3Cg horizons, when present, have hues of N, 10YR, 2.5Y, 5Y, or 5GY, value of 2 through 5, and chroma of 0 through 2. Textures are loamy sand through coarse sand along with gravelly analogs. Consistence is nonfluid. Gravel content is 0 to 25 percent.
The C or 2C horizons, when present, have hues of 5Y, value of 4, and chroma of 3. Textures are fine sandy loam through loamy sand. Consistence is nonfluid. Gravel content is 0 to 10 percent.
COMPETING
SERIES: There are no competing series in the same family. The Quanaduck
(T) and Saltpond series are in closely related families. Quanaduck soils are in
mainland cove landforms and have a contrasting particle-size class family of
coarse-silty over sandy or sandy-skeletal. Saltpond soils are on coastal plain
and barrier island landscapes that are not permanently submerged.
GEOGRAPHIC
SETTING: The Wamphassuc soils are permanently submerged with salt or
brackish water in drowned stream valleys and terraces that undergo minimal
currents and wave action. Slope ranges from 0 to 2 percent. The soils formed in
loamy marine sediments. Wamphassuc soils can be found up to 1.5 meters deep
under water.
GEOGRAPHICALLY
ASSOCIATED SOILS: These are the Anguilla
(T), Napatree (T), Quanaduck (T), and Wequetequock (T) soils. Wequetequock
soils have an n-value greater than 0.7 in all horizons. Quanaduck and
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Subaqueous, peraquic moisture regime, moderately high to high saturated hydraulic conductivity due to low bulk density. Soil is permanently submerged with salt or brackish water.
USE AND VEGETATION: This soil supports submerged aquatic vegetation and wildlife habitats. The area is used by recreational fishermen for the harvest of crabs. In addition fishing is commonplace and the species found in the area are smelt, small cod, flounder, scup, menhaden, and white perch. Some areas are vegetated with native rooted and floating algae and eelgrass (Zostera marina). Vegetative cover ranges from 0 to 15 percent.
DISTRIBUTION AND EXTENT: Permanently submerged stream valleys in MLRA 144A. The soils of this series are not extensive; their total extent is about 50 hectares in Little Narragansett Bay, New London County, Connecticut, MLRA 144A.
MLRA OFFICE
RESPONSIBLE:
SERIES PROPOSED:
REMARKS:
The Keys to Soil Taxonomy, Tenth Edition, 2006
states that the horizontal boundaries of soil are areas where the soil grades
into deep water (typically less than 2.5 m). This subaqueous series is being
proposed in areas previously mapped as water in the Connecticut Soil Survey.
Using the proposed taxonomy for subaqueous soils, the series classifies as a coarse-loamy, mixed, active, nonacid, mesic Haplic Sulfiwassents.
Diagnostic horizons and features in this pedon include:
1. Peraquic feature - positive soil water potential (permanently submerged) at the soil surface (under 0.6 m of water at the time of coring).
2. Particle-size control section the zone from 25 to 100 cm (part of the ACg1, ACg2, Cg1, Cg2 and part of the Cg3 horizon).
3. Ochric epipedon the zone from 0 to 15 cm (Ag horizon)
4. Sulfidic materials the zone from the 39 to 140 cm (Cg1, Cg2, Cg3, Cg4, 2Cg)
5. Gleyed horizons the zone from 0 to 210 cm (All
of the horizons).
6. Lithologic
discontinuity contrasting soil materials at 122 cm (2Cg horizon).
ADDITIONAL DATA: Pedon
sample S06CT011004 in
National Cooperative Soil Survey