LOCATION
Tentative series
Rev. DCP/DAS/SJM
4/07
WEQUETEQUOCK SERIES
The Wequetequock series consists of very
deep, subaqueous soils in submerged stream valleys and terraces. The Wequetequock soils are formed in loamy marine
deposits. 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 Typic Sulfaquents.
TYPICAL PEDON: Wequetequock silt loam on a south facing, concave slope in a submerged stream valley under 1.3 m of estuarine water (Colors are for moist soil).
Ag—0 to 15 cm; black (N 2.5/) silt loam; massive; very fluid; 5 percent unrubbed and 5 percent rubbed herbaceous fibers; sulphurous odor; strongly saline (30 ppt); slightly acid (pH 6.3); very strongly acid (pH 4.7) after 8 weeks; clear boundary.
Cg1—15 to 40 cm; black (N 2.5/) silt loam; massive; very fluid; 1 percent unrubbed and 0 percent rubbed herbaceous fibers; sulphurous odor; strongly saline; moderately acid (pH 5.8); very strongly acid (pH 4.9) after 8 weeks; clear boundary.
Cg2—40 to 60 cm; very dark gray (2.5Y 3/1) silt loam; single grain; moderately fluid; sulphurous odor; strongly saline; very strongly acid (pH 4.9); extremely acid (pH 4.0) after 8 weeks; clear boundary.
Cg3—60 to 105 cm; very dark gray (2.5Y 3/1) sandy loam; massive; moderately fluid; 6 percent gravels; sulphurous odor; strongly saline; ultra acid (pH 3.1); ultra acid (pH 2.6) after 8 weeks; abrupt boundary. (20 to 90 cm thick)
2Oeb—105 to 150 cm; dark brown (7.5YR 3/3) muck, broken face sapric material, very dark grey (10YR 3/1) rubbed; massive; very fluid; about 48 percent mineral content; 16 percent unrubbed and 2 percent rubbed herbaceous fibers; 2650 +/- 40 BP measured and 2600 +/- 40 BP conventional radiocarbon age; sulphurous odor; neutral (pH 6.6); neutral (pH 6.6) after 8 weeks; strongly saline. (20 to 45 cm thick)
TYPE LOCATION: New London County, Connecticut; located about 600 feet south of the Providence and Worcester Rail Road Bridge and 1000 feet northeast of Goat Island in Wequetequock Cove, USGS Mystic topographic quadrangle; lat. 41 degrees 20 minutes 61 seconds N. and long. 71 degrees 53 minutes 3.8 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: The soils are permanently submerged. One or more horizons within 50 cm have a pH of 4.0 or less after 8 weeks incubation. Some pedons are underlain by organic deposits greater than 100 cm from the soil surface and/or have thin layers less than 20 cm thick of organic deposits in the soil profile. Electrical conductivity is >16 mmhos/cm and salinity is >18 ppt (strongly saline) throughout the profile.
The Ag or ACg horizon, when present, has hue of N or 2.5Y, value of 2.5, and of chroma 0 or 1. Textures are mucky silt loam or silt loam. Organic matter is 5 to 15 percent. Consistence is very fluid. Reaction is very strongly acid through slightly alkaline and ultra acid through moderately acid after 8 weeks incubation.
The Cg, 2Cg, and 3Cg horizons, when present, have hues of 2.5Y or 5Y, value of 2 through 3, and chroma of 1 or 2. Textures are mucky silt loam through sandy loam. Gravel content is 0 to 20 percent. The consistence of the Cg is slightly fluid through very fluid. The consistence of the 2Cg and 3Cg is nonfluid through slightly fluid. Reaction is ultra acid through moderately alkaline and ultra acid through slightly acid after 8 weeks incubation.
The 2Oab and 2Oeb horizons, when present, have hues of 10YR through 5YR, value of 2 or 3, and chroma of 1 through 3. It is muck or mucky peat. Organic matter is 40 to 70 percent. Consistence is moderately fluid or very fluid. Reaction is neutral through moderately alkaline and extremely acid through moderately alkaline after 8 weeks incubation.
The C horizon, when present, has hue of 2.5Y, value of 4, and chroma of 3. Texture is sandy loam through loamy coarse sand. Gravel content is 0 to 25 percent. Reaction is ultra acid through moderately alkaline and ultra acid through slightly acid after 8 weeks incubation.
COMPETING
SERIES: There
are no competing series. The Saltpond soils are in related families. The
Saltpond series has a sandy particle-size control section.
GEOGRAPHIC SETTING: The Wequetequock 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 deposits and can be found up to 1.5 meters deep under water.
GEOGRAPHICALLY
ASSOCIATED SOILS: These are the Anguilla
(T), Napatree (T), Quanaduck (T), and Wamphassuc (T) soils.
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; approximately 50 hectares is mapped in Little Narragansett Bay.
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 Fluvic Sulfiwassents
Diagnostic horizons and features in this pedon include:
1. Peraquic feature - positive soil water potential (permanently submerged) at the soil surface (under 1.3 m of water at the time of coring).
2. Particle-size control section – the zone from 25 to 100 cm (Part of the Cg1, Cg2, and Cg3 horizons).
3. Ochric epipedon – the zone from 0 to 15 cm (Ag horizon)
4. Sulfidic materials – the zone from 40 to 105 cm (Cg2 and Cg3 horizon).
5. Lithologic discontinuity – contrasting soil materials at 105 cm (2Oab horizon).
6. Buried soil feature – the zone from 105 to 150 cm (the 2Oab horizon).
7. High n-value – the zone from 0 to 150 cm has an n-value greater than or equal to 0.7.
ADDITIONAL DATA:
Pedon samples S05CT011006 and S06CT011002 New London County, Connecticut and
S06RI009002 Washington County, Rhode Island by NSSL,
National Cooperative Soil Survey