LOCATION TRAPPE MDTentative Series
TAXONOMIC CLASS: Siliceous, mesic Typic Psammaquents
TYPICAL PEDON: Trappe loam on a smooth 0.1 percent slope in a shallow mainland cove under 1.1 feet of permanent estuarine water. (Colors are for moist soil.)
A--0 to 2 inches; light olive brown (2.5Y 5/3) loam; common medium distinct black (N 2/0) mottles; massive; friable; n-value 0.9, material flows easily between fingers when squeezed; common fine and many very fine roots; moderately alkaline; strongly saline; abrupt smooth boundary. (1 to 6 inches thick)
Cg1--2 to 7 inches; very dark gray (5Y 3/1) sandy loam; few fine faint dark gray (5Y 4/1) mottles; massive; friable; n-value 0.8, material flows with some difficulty between fingers when squeezed; few fine and many very fine roots; moderately alkaline; strongly saline; clear smooth boundary.
Cg2--7 to 15 inches; olive gray (5Y 4/2) sand; few fine distinct dark gray (N 4/0) mottles; single grain; loose; 20 percent, by volume shell fragments; 2 percent, by volume dark brown (7.5YR 3/3) organic fragments; few very fine roots; slightly alkaline; strongly saline; clear smooth boundary. (Combined thickness of the Cg horizon is 15 to 24 inches.)
C3--15 to 33 inches; light olive brown (2.5Y 5/3) sand; single grain; loose; 1percent dark brown (7.5YR 3/3) organic fragments; slightly alkaline; strongly saline; abrupt smooth boundary. (20 to 48 inches thick)
2C4--33 to 60 inches; olive (5Y 5/4) coarse sand; few medium prominent very dark gray (5Y 3/1) mottles; single grain; loose; 5 percent, by volume gravel; slightly alkaline; strongly saline.
TYPE LOCATION: Worcester County, Maryland; approximately 0.25 mile south of the western end of the Verrazano Bridge, 100 feet east of the mainland, Sinepuxent Bay, in a mixed seagrass meadow; lat.38 degrees, 14 minutes, 17.48 seconds N. and long. 75 degrees, 9 minutes, 48.08 seconds W.
RANGE IN CHARACTERISTICS:
Depth to Bedrock: Greater than 80 inches
Depth to Seasonal High Water Table: Permanently submersed
Depth to Lithologic Discontinuity: 30 to greater than 50 inches
Shell Fragments: 0 to 20 percent, by volume throughout the profile
Soil Reaction: Slightly alkaline or moderately alkaline throughout the profile
Electrical Conductivity: Greater than 16 mmhos/cm throughout the profile
Salinity: Greater than 25 ppt throughout the profile
RANGE OF INDIVIDUAL HORIZONS:
A or Ag horizon:
Color--hue of 10YR to 5Y, value of 3 to 5, and chroma of 1 to 3, or is neutral with value of 3 to 5
Texture (fine-earth fraction)--loam, sandy loam, or loamy sand
Cg horizon:
Color--hue of 10YR to 10Y, value of 3 to 6, and chroma of 1 or 2, or is neutral with value of 3 to 6
Texture (fine-earth fraction)--sandy loam or loamy sand
C horizon:
Color--hue of 2.5Y to 10Y, value of 3 to 6, and chroma of 3 or 4, or is neutral with value of 3 to 6
Texture (fine-earth fraction)--sand or loamy sand
2C horizon:
Color--hue of 2.5Y or 5Y, value of 3 to 6, and chroma of 3 or 4
Texture (fine-earth fraction)--loamy coarse sand or coarse sand
2Cg horizon (if it occurs):
Color--hue of 2.5Y or 5Y, value of 3 to 6, and chroma of 1 or 2, or is neutral with value of 3 to 6
Texture (fine-earth fractionm)--loamy coarse sand or coarse sand
COMPETING SERIES:
Demas soils (tentative)--do not have layers with chroma of 3 or more, at slightly deeper water depths
Whittington soils (tentative)--do not have underlying layers with chroma of 3 or more, formed from barrier island overwash sediments, at slightly shallower water depths
GEOGRAPHIC SETTING:
Landscape: Mid-Atlantic Coastal Plain Estuaries
Landform: Shallow mainland coves
Parent Material: Mixed estaurine sediments underlain by paleo-terrestrial sandy upland deposits
Slope: 0 to 1 percent
Mean Annual Air Temperature: 50 to 57 degrees F.
Mean Annual Water Temperature: 52 to 58 degrees F.
Bathymetry: 1.0 to 4.5 feet below mean sea level
Water Regime: Tidal, 1.0 to 2.0 feet tidal range
GEOGRAPHICALLY ASSOCIATED SOILS:
Demas soils (tentative)--do not have layers with chroma of 3 or more, at slightly deeper water depths
Southpoint soils (tentative)--have a buried histic epipedon within 40 inches of the surface; at deeper water depths
Transquaking soils--have surface organic layers more than 51 inches thick and are not permanently submersed; on adjacent tidal marshes
Mispillion soils--have surface organic layers 16 to 51 inches thick and are not permanently submersed; on adjacent tidal marshes
Purnell soils--have surface organic layers 8 to 15 inches thick and are not permanently submersed; on adjacent tidal marshes
DRAINAGE AND PERMEABILITY:
Agricultural Drainage Class: Very poorly drained (permanently submersed)
Index Surface Runoff: Negligible
Permeability: Moderate to very rapid
USE AND VEGETATION:
Major Uses: Most areas are vegetated and function as estuarine benthic wildlife habitat. Benthic fauna such as tubeworms, clams, juvenile blue crabs, scallops and juvenile finfish are common.
Dominant Vegetation: Native vegetation includes rooted algae, eelgrass (Zostera marina) and widgeon grass (Ruppia maritima). Vegetative cover ranges from 25 to 100 percent.
DISTRIBUTION AND EXTENT: The mid-Atlantic coastal estuaries of Maryland and Delaware and possibly Virginia. This series is of small extent.
MLRA OFFICE RESPONSIBLE: Morgantown, West Virginia
SERIES PROPOSED: Worcester County, Maryland, 1998.
REMARKS: Trappe soils were formerly included with miscellaneous areas of water. They are distinguished by being permanently covered by estuarine waters that support submersed aquatic vegetation. These soils would classify in the proposed "Subaquic" subgroup. The initial name proposed for this series was "Newport". It was revised to "Queponca" and later changed to Trappe.
Refer to "Subaqueous Soil Survey of Sinepuxent Bay, Maryland;" G.P. Demas, J.H. Brown, and M.C. Rabenhorst; July 1998. Possible groundwater intrusion occurs at a depth of 15 to 60 inches.
Diagnostic horizons and other diagnostic soil characteristics recognized in this pedon are:
Ochric epipedon (oxidized)--the zone from 0 to 2 inches (A horizon)
Peraquic feature--the zone from 0 to 60 inches is permanently saturated
ADDITIONAL DATA:
Data Map Unit ID: To be developed