LOCATION
Tentative series
Rev. DAS/SJM
4/07
RHODESFOLLY SERIES
The Rhodesfolly series consists of very deep, subaqueous soils on bay bottoms, depositional
beaches, washover fans, and shore faces. The Rhodesfolly
soils are formed in sandy marine deposits. Slope ranges from 0 to 5 percent, mean
annual air temperature is about 10 degrees C., and mean annual precipitation is
about 1142 mm.
TAXONOMIC CLASS: Mixed, mesic Typic Psammaquents
TYPICAL PEDON: Rhodesfolly fine sand on a north facing, nearly level slope in a shoreface under 1.3 m of estuarine water (Colors are for moist soil).
Ag—0 to 13 cm; very dark gray (N 3/) fine sand; white (5Y 8/1) dry; single grain; nonfluid; 4 percent gravels; 2 percent shell fragments; sulphurous odor; strongly saline (32 ppt); slightly alkaline (pH 7.6), slightly alkaline (pH 7.6) after 8 weeks; abrupt boundary. (0 to 23 cm thick)
Cg —13 to 20 cm; dark gray (5Y 4/1) coarse sand; light greenish gray (10Y 7/1) dry; single grain; nonfluid; 12 percent gravels; 20 percent mixed white and blue mussel shell fragments sulphurous odor; strongly saline; moderately alkaline (pH 8.0); slightly alkaline (pH 7.8) after 8 weeks; abrupt boundary. (Thickness of the Cg horizons is 6 to 68 cm thick)
Agb —20 to 29 cm; black (N 2.5/) coarse sand; greenish gray (10Y 6/1) dry; single grain; nonfluid; 5 percent herbaceous fibers, 0 percent rubbed; 6 percent gravels; 50 percent shell fragments; sulphurous odor; strongly saline; moderately alkaline (pH 8.2); slightly alkaline (pH 7.6) after 8 weeks; abrupt boundary. (Thickness of the Ab horizons is 4 to 22 cm thick)
C’g1—29 to 39 cm; very dark gray (2.5Y 3/1) coarse sand; greenish gray (10Y 6/1) dry; single grain; nonfluid; 7 percent gravels; 10 percent white mussel shell fragments; strongly saline; moderately alkaline (pH 8.4); slightly alkaline (pH 7.6) after 8 weeks; clear boundary.
C’g2 --39 to 61 cm; gray (N 5/) coarse sand; light gray (N 7/) dry; single grain; nonfluid; 1 percent gravels; 2 percent shell fragments; sulphurous odor; strongly saline; strongly alkaline (pH 8.6); slightly alkaline (pH 7.5) after 8 weeks; clear boundary.
A’gb—61 to 72 cm; very dark gray (2.5Y 3/1) coarse sand; gray (N 6/) dry; single grain; nonfluid; 3 percent herbaceous fibers, 0 percent rubbed; 3 percent gravels; 20 percent mussel shell fragments; sulphurous odor; strongly saline; strongly alkaline (pH 8.7); slightly alkaline (pH 7.6) after 8 weeks; clear boundary.
C’’g —72 to 78 cm; dark gray (2.5Y 4/1) coarse sand; gray (N 6/) dry; single grain; nonfluid; 11 percent gravel; sulphurous odor; strongly saline; moderately alkaline (pH 8.6); slightly alkaline (pH 7.7) after 8 weeks; abrupt boundary.
A’’’gb1—78 to 82 cm; very dark gray (2.5Y 3/1) gravelly coarse sand; gray (N 6/) dry; single grain; nonfluid; 1 percent herbaceous fibers, 0 percent rubbed; 22 percent gravels; 25 percent soft shell clam fragments; sulphurous odor; strongly saline; moderately alkaline (pH 8.4); slightly alkaline (pH 7.6) after 8 weeks; abrupt boundary.
A’’’gb2 --82 to 92 cm; greenish black (10Y 2.5/1) fine sand; gray (5Y 5/1) dry; single grain; nonfluid; 2 percent herbaceous fibers, 0 percent rubbed; 22 percent gravels; sulphurous odor; strongly saline; moderately alkaline (pH 8.3); slightly acid (pH 6.3) after 8 weeks; abrupt boundary.
C’’’g—92 to 150 cm; dark gray (5Y 4/1) fine sand; gray (5Y 6/1) dry; single grain; nonfluid; sulphurous odor; strongly saline; moderately alkaline (pH 8.4); slightly acid (pH 6.2) after 8 weeks.
TYPE LOCATION: New London County, Connecticut; located about 8825 feet southeast from the intersection of the Providence and Worcester Railroad and Island Road, and 6900 feet southwest of Barn Island boat launch, south of Sandy Point, USGS Mystic topographic quadrangle; lat. 41 degrees 19 minutes 6.3 seconds N. and long. 71 degrees 52 minutes 38.8 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: The soils are permanently submerged. All horizons have a pH of neutral through strongly alkaline and a pH of very strongly acid through slightly alkaline after 8 weeks incubation. Electrical conductivity is >16 mmhos/cm and salinity is >25 ppt (strongly saline) throughout the profile.
The Ag and ACg horizons, when present, have hues of N or 10Y, value of 2.5 or 3, and chroma of 0 or 1. Textures include loamy fine sand through coarse sand. Organic matter is 0 to 2 percent. Gravel content is 0 to 10 percent. Shell fragment content is 0 to 10 percent. Consistence is nonfluid.
The CAg horizon, when present,
has hue of 5Y, value of 3 through 6, and chroma of 0 through 2. Textures
include sandy loam through sand. Gravel content is 0 to 5 percent. Consistence
is nonfluid.
The Agb horizon has hue of N, 7.5YR, 5Y, 10Y or 2.5Y, value of 2.5 or 3, and chroma of 0 through 2. Textures include very fine sandy loam, fine sand, mucky sand, sand, or coarse sand in the fine earth fraction. Organic matter is 0 to 2 percent. Gravel content is 0 to 25 percent. Shell fragment content is 0 to 50 percent. Herbaceous fibers are 0 to 10 percent unrubbed and 0 to 5 percent rubbed. Consistence is nonfluid.
The Cg horizon has hue of 5Y, 10Y, 2.5Y or N, value of 2.5 through 5, and chroma of 0 through 2. Textures include loamy sand through coarse sand in the fine earth fraction. Gravel content is 0 to 20 percent. Shell fragment content is 0 to 40 percent. Consistence is nonfluid.
The 2Cg horizon, when present, has hue of 5Y, value of 2 through 5, and chroma of 0 through 2. Textures include sandy loamy through sand. Gravel content is 0 to 5 percent. Consistence is nonfluid.
COMPETING
SERIES: These are the Arloval, Barren, Carrolls, Conrad, Dair,
Forbar,
GEOGRAPHIC SETTING:
The Rhodesfolly soils are permanently submerged with strongly saline water on unstable
bay bottoms, depositional beaches, shore faces and washover fans that are sandy. Slope ranges from 0
to 5 percent. The soils formed in sandy deposits with numerous buried horizons
from catastrophic storm events that breeched the barrier island or spit. The shore
face and washover fan landforms are nearly level to gently sloping with steeper
edges leading into deeper waters. The soil is subject to depositional change
due to severe storm events. Wave action
and strong currents influence the formation of these soils. These soils occur
in water depths of up to 2.5 meters.
GEOGRAPHICALLY ASSOCIATED SOILS: These
are the Anguilla (T) and Napatree (T) soils.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Subaqueous, peraquic soil moisture regime, and high
to very high saturated hydraulic conductivity. Soil is permanently submerged
with salt or brackish water.
USE AND VEGETATION:
These soils are used for recreation and benthic wildlife habitat. 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 algae and
eelgrass (Zostera marina). Vegetative cover ranges from 0 to 35 percent.
DISTRIBUTION AND EXTENT: The soils of this series are of small extent,
approximately 180 hectares mapped in Little Narragansett Bay, in the
southeastern part of
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 mixed, mesic
Fluventic Psammowassents.
Diagnostic horizons
and features in this pedon include:
1. Peraquic feature - positive soil water potential (permanently submerged) at the soil surface (under 126 cm of salt water at the time of coring).
2. Particle-size
control section – the zone from 25 to 100 cm.
3. Ochric epipedon –
the zone from 0 to 13 cm (Ag horizon).
3. Gleyed horizons – the zone from 0 to 150 cm.
ADDITIONAL
DATA: Partial reference sample from S05RI0009007 and S05RI0009008 Washington
County, Rhode Island, by SSL,
National Cooperative
Soil Survey