LOCATION DEMAS MDTentative Series
TAXONOMIC CLASS: Siliceous, mesic Typic Psammaquents
TYPICAL PEDON: Demas loamy sand on a smooth 0 percent slope along the transitional edge of an island under 1.5 feet of permanent estuarine water. (Colors are for moist soil.)
Ag--0 to 1 inches; dark olive gray (5Y 3/2) loamy sand; massive; very friable; common fine and very fine roots; 15 percent, by volume dark brown (7.5YR 3/3) organic fragments; moderately alkaline; strongly saline; abrupt smooth boundary. (1 to 7 inches thick)
Cg1--1 to 7 inches; greenish black (10Y 2.5/1) sand; common medium distinct black (N 2/0) mottles; single grain; loose; few very fine roots; 2 percent, by volume shell fragments; moderately alkaline; strongly saline; gradual smooth boundary.
Cg2--7 to 27 inches; greenish black (10Y 2.5/1) sand; single grain; loose; 3 percent, by volume very dark grayish brown (2.5Y 3/2) organic fragments; slightly alkaline; strongly saline; clear smooth boundary.
Cg3--27 to 38 inches; greenish gray (5GY 5/1) sand; single grain; loose; 4 percent, by volume shell fragments; slightly alkaline; strongly saline; abrupt smooth boundary. (Combined thickness of the Cg horizon is 33 or more inches.)
2Cg4--38 to 60 inches; greenish gray(5GY 5/1) coarse sand; single grain; loose; 20 percent, by volume shell fragments; slightly alkaline; strongly saline.
TYPE LOCATION: Worcester County, Maryland; approximately 100 feet east of the center of Great Egging Island, Sinepuxent Bay, in a mixed seagrass meadow; lat. 38 degrees, 12 minutes, 5.21 seconds N. and long. 75 degrees, 10 minutes, 47.36 seconds W.
RANGE IN CHARACTERISTICS:
Depth to Bedrock: Greater than 80 inches
Depth to Seasonal High Water Table: Permanently submersed
Depth to Lithologic Discontinuity: Greater than 35 inches
Shell Fragments: 0 to 30 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:
Ag horizon:
Color--hue of 10YR to 5Y, value of 3 to 5, and chroma of 1 or 2, or is neutral with value of 3 to 5
Texture (fine-earth fraction)--loamy sand or 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)--sand or loamy sand
2Cg horizon:
Color--hue of 2.5Y 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)--loamy coarse sand or coarse sand
COMPETING SERIES:
Trappe soils (tentative)--have underlying layers with chroma of 3 or more, at slightly shallower water depths
Whittington soils (tentative)--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
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 3.0 feet tidal range
GEOGRAPHICALLY ASSOCIATED SOILS:
Southpoint soils(tentative)--have a buried histic epipedon within 40 inches of the surface; at deeper water depths
Sinepuxent soils (tentative)--have a coarse-loamy particle-size control section and contai sulfidic materials, at shallower water deths
Whittington soils (tentative)--formed in barrier island overwash sediments, at slightly shallower water depths
Tizzard soils (tentative)--have a coarse-loamy particle-size control section, have underlying layers with chroma of 3 or more, at slightly shallower water depths
Queponca soils (tentative)--have layers with chroma of 3 or more, at slightly shallower water depths
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: Moderately rapid or 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 20 to 90 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: Demas 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 "Wallops". Refer to "Subaqueous Soil Survey of Sinepuxent Bay, Maryland;" G.P. Demas, J.H. Brown, and M.C. Rabenhorst; July 1998.
Diagnostic horizons and other diagnostic soil characteristics recognized in this pedon are:
Ochric epipedon (oxidized)--the zone from 0 to 1 inches (A horizon)
Peraquic feature--the zone from 0 to 60 inches is permanently saturated
ADDITIONAL DATA:
Data Map Unit ID: To be developed