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Massapog Subaqueous Soils

Soil Map Unit Description from the RI Soil Survey Report (2010 Update)

WMg0: Massapog sand, 0 to 1 meter water depth (2010 Update for the RI Coastal Zone Soil Survey Phase I - please download the latest copy of the spatial data).

This subaqueous soil is found on flood tidal delta flats in coastal lagoons and bays along the south shore of Washington County, RI. Areas are irregular or fan-shaped and are found adjacent to an inlet. Areas range in size from 1 to 28 hectares (1 to 70 acres). Slopes range from 0 to 2 percent.

Typically, this soil has a nonfluid, gray, sand surface and subsoil, 1 to 2 meters thick, derived from estuarine and marine sands deposited as a result of tidal currents through an inlet. The subsoil may contain buried black horizons or lenses representing old soil surfaces. Some areas are covered with shell fragments and macro algae.

This soil is permanently submerged beneath up to 1 meter of salt or brackish water, though at extreme low tides some areas may become exposed. All horizons have a slightly alkaline pH in place and some horizons may develop an acidic pH after oxidation.

These soils are often located on a very active landscape where deposition and erosion is continuously occurring with each tidal cycle and major changes in landscape may occur with storm events. Dredging is common in these soils to maintain navigation channels.

Included with this soil are small areas of Marshneck soils on the deeper edge of the flood tidal delta where fine material may accumulate on the soil surface. Nagunt soils may also be included in this map unit and are found on washover fan flats and slopes in coastal lagoons and contain sulfidic materials. Included areas make up about 10 percent of this map unit.

Areas of this map unit have been dredged as part of beach replenishment and restoration projects, particularly in Ninigret Pond. This restoration project occurred after the soils were mapped and have not been changed to reflect the dredging, these areas are covered with eelgrass and macro algae.

The unstable nature of these soils makes them poorly suited for aquaculture practices and eelgrass replanting (unless the area is dredged for replenishment or restoration efforts). Eelgrass may populate these soils, but is transient and often grows as an annual in these areas. This soil is heavily used for recreational harvesting of quahogs and provides important habitat for shellfish and wading birds.

Link to Official Series Description - MaSSAPOG | Soil Profile Photo of MaSSAPOG Series

UPDATE: The Coastal Zone of Rhode Island is currently being updated and re-mapped, for more information on this update visit: www.mapcoast.org

 

WMg1: Massapog sand, 1 to 2 meter water depth (2010 Update for the RI Coastal Zone Soil Survey Phase I - please download the latest copy of the spatial data)

This subaqueous soil is found on flood tidal delta flats and relict flood tidal delta channels in coastal lagoons and bays. Areas are irregular or fan-shaped and are found adjacent to an inlet. Areas range in size from 0.5 to 4 hectares (1 to 10 acres). Slopes range from 0 to 2 percent.

Typically, this soil has a nonfluid, gray, sand surface and subsoil, 1 to 2 meters thick, derived from estuarine and marine sands deposited as a result of tidal currents through an inlet. The subsoil may contain buried black horizons or lenses representing old soil surfaces. The subsoil may contain buried black horizons or lenses representing old soil surfaces. Some areas are covered with shell fragments and macro algae.

This soil is permanently submerged beneath 1 to 2 meters of salt or brackish water. All horizons have a slightly alkaline pH in place and some horizons may develop an acidic pH after oxidation.

These soils are often located on a very active landscape where deposition and erosion is continuously occurring with each tidal cycle and major changes in landscape may occur with storm events. Dredging is common in these soils to maintain navigation channels.

Included with this soil are small areas of Marshneck soils on the deeper edge of the flood tidal delta where fine material may accumulate on the soil surface. Nagunt soils may also be included in this map unit and are found on washover fan flats and slopes in coastal lagoons and contain sulfidic materials. Included areas make up about 10 percent of this map unit.

Areas of this map unit have been dredged as part of beach replenishment and restoration projects, particularly in Ninigret Pond. This restoration project occurred after the soils were mapped and have not been changed to reflect the dredging, these areas are covered with eelgrass and macro algae.

The unstable nature of these soils makes them poorly suited for aquaculture practices and eelgrass replanting. Eelgrass may populate these soils, but is transient and often grows as an annual in these areas. This soil is heavily used for recreational harvesting of quahogs and provides important habitat for shellfish.

Link to Official Series Description - MaSSAPOG | Soil Profile Photo of MaSSAPOG Series

UPDATE: The Coastal Zone of Rhode Island is currently being updated and re-mapped, for more information on this update visit: www.mapcoast.org

 


WMgT: Massapog sand, intertidal (2010 Update for the RI Coastal Zone Soil Survey Phase I - please download the latest copy of the spatial data)

This subaqueous soil is found on flood tidal delta flats in coastal lagoons and bays. Areas are irregular and are found adjacent to an inlet. Areas range in size from 0.5 to 4 hectares (1 to 10 acres). Slopes range from 0 to 2 percent.

Typically, this soil has a nonfluid, gray, sand surface and subsoil, 1 to 2 meters thick, derived from estuarine and marine sands deposited as a result of tidal currents through an inlet. The subsoil may contain buried black horizons or lenses representing old soil surfaces. Some areas are covered with shell fragments and macro algae.

This soil is intermittently exposed at low tides, but generally covered with shallow salt or brackish water. All horizons have a slightly alkaline pH in place and some horizons may develop an acidic pH after oxidation.

These soils are often located on a very active landscape where deposition and erosion is continuously occurring with each tidal cycle and major changes in landscape may occur with storm events. Dredging is common in these soils to maintain navigation channels.

Included with this soil are small areas of Nagunt soils may also be included in this map unit and are found on washover fan flats and slopes in coastal lagoons and contain sulfidic materials. Areas of this map unit have been dredged as part of replenishment and restoration project, particularly in Ninigret Pond. This restoration project occurred after the soils were mapped and have not been changed to reflect the dredging, these areas are covered with eelgrass and macro algae.   Included areas make up about 5 percent of this map unit.

The unstable and intertidal nature of these soils makes them poorly suited for aquaculture practices and eelgrass replanting. This soil is heavily used for recreational harvesting of quahogs and provides important habitat for shellfish and wading birds.

Link to Official Series Description - MaSSAPOG | Soil Profile Photo of MaSSAPOG Series

UPDATE: The Coastal Zone of Rhode Island is currently being updated and re-mapped, for more information on this update visit: www.mapcoast.org

 


WMd: Massapog sand, dredged phase (2010 Update for the RI Coastal Zone Soil Survey Phase I - please download the latest copy of the spatial data)

This subaqueous soil is found on dredged tidal inlets in coastal lagoons and bays along Washington County, RI. Areas are linear in shape and range in size from 4 to 60 hectares (10 to 150 acres). Slopes range from 0 to 10 percent.

Typically, this soil has a nonfluid, gray, sand surface and subsoil, 1 to 2 meters thick, derived from estuarine and marine sands deposited as a result of tidal currents through an inlet. Some areas may have a shelly, gravelly or very gravelly surface.

This soil is permanently submerged beneath at least 2 meters of salt or brackish water.

These soils are often located on a very active landscape where deposition and erosion is continuously occurring with each tidal cycle and major changes in landscape may occur with storm events. Dredging is common in these soils to maintain navigation channels.

Included with this soil are small areas of Anguilla or Napatree soils may also be included in this map unit in areas where soils have been dredged down to the glacial material below. Included areas make up about 10 percent of this map unit.

This soil generally does not support rooted vegetation. Some areas have native algae cover. Vegetative cover is less than 10 percent.

Link to Official Series Description - MaSSAPOG | Soil Profile Photo of MaSSAPOG Series

 

UPDATE: The Coastal Zone of Rhode Island is currently being updated and re-mapped, for more information on this update visit: www.mapcoast.org