LOCATION LANEXA VAEstablished Series
TAXONOMIC CLASS: Clayey, mixed, euic, thermic Terric Haplosaprists
TYPICAL PEDON: Lanexa mucky silty clay - in a marsh. (Colors are for moist soil. When described, the soil was saturated to the surface.)
A--0 to 15 inches; very dark grayish brown (10YR 3/2) mucky silty clay; massive; sticky, slightly plastic; soil flows easily between fingers when squeezed and leaves a small residue and few fine fibrous roots; many fine live roots; moderate sulfide odor; extremely acid, clear smooth boundary. (0 to 15 inches thick)
Oa--15 to 40 inches; very dark grayish brown (2.5Y 3/2) muck (sapric material); about 5 percent fibers rubbed; massive; slightly sticky, slightly plastic; flows easily between fingers when squeezed; weak sulfide odor; common fine roots and fibers; common lenses and pockets of clay loam; very strongly acid; clear smooth boundary. (16 to 45 inches thick)
Cg--40 to 60 inches; very dark grayish brown (2.5Y 3/2) mucky silty clay; massive; sticky, slightly plastic; flows easily between fingers when squeezed leaving a small residue and few fine fibrous roots; common pockets of sapric and hemic material; extremely acid.
TYPE LOCATION: New Kent County, Virginia; 1 3/4 miles south of junction of VA-627 and VA-1002, or 700 feet south of the junction of Captain Smith and Colonial Trail roads in the Colonies subdivision, and 100 feet north of marsh channel in the Chickahominy River.
RANGE IN CHARACTERISTICS: The thickness of the organic layers ranges from 16 to 51 inches. The soil ranges from extremely acid through slightly acid in the natural state. Upon drying, the reaction usually drops slightly. The sulfur content ranges from 0.2 to 0.75 percent and usually decreases with depth. The n- value of the mineral and organic materials in the control section ranges from 2 to 4. The organic materials are mostly from herbaceous plants. Thin lenses and strata of mineral soil materials are in the control section of most pedons.
The mineral and organic materials within the surface and subsurface tiers are neutral or have hue of 10YR through 5GY, value of 2 through 4, and chroma of 0 through 2. The organic material is dominantly sapric but some pedons have thin surface layers that are hemic. The mineral materials are mucky analogues of silt loam, silty clay loam, or silty clay.
The Cg horizon is neutral or has hue of 10YR through 5GY, value of 2 through 5, and chroma of 0 through 2. Texture is variable and is commonly stratified, but the weighted average clay content in the particle size control section is greater than 35 percent.
COMPETING SERIES: These are the Kingile and Webile series. The Kingile and Webile soils have rapid permeability in the organic materials and, in addition, have a mean annual precipitation of 16 inches, and a lower salinity content in the surface layers. Similar soils in related families include the Axis, Backbay, Bohicket, Dorovan, Levy, Mattan, Pocaty, and Rappahannock series. Axis, Backbay, Bohicket, and Levy are mineral soils. Dorovan soils have organic materials thicker than 51 inches. Mattan soils are underlain by loamy sediments and formed in both herbaceous and woody plant remains. Pocaty and Rappahannock soils have more than 0.75 percent sulfur in the control section.
GEOGRAPHIC SETTING: Lanexa soils are on fresh to slightly brackish water tidal marshes along rivers and creeks of the Atlantic Coastal Plain. They are regularly flooded by tides and occasionally by wind tides. Salt content is generally higher in the flood waters during prolonged dry summer and early fall months of most years. The soils formed mostly in herbaceous plant remains and stratified fluvial sediments. The climate is humid temperate with mean annual precipitation of about 45 inches and mean annual temperature of about 58 degrees F near the type location.
GEOGRAPHICALLY ASSOCIATED SOILS: In addition to the competing Axis, Bohicket, Mattan, and Levy soils, these are the Altavista, Augusta, Catpoint, Dragston, Munden, Nawney, Nimmo, Seabrook, and Tomotley soils. Except for Mattan, all of these are mineral soils. In addition, the Nawney soils are on drainageways at slightly higher elevations.
DRAINAGE AND PERMEABILITY: Very poorly drained; moderate permeability in the organic layers and very slow permeability in the underlying mineral layers. Fluctuating tides inundate the surface daily. The water table fluctuates from 6 inches below the surface to 24 inches above the surface most of the time. Wind tides and storm tides cause inundation up to 36 inches.
USE AND VEGETATION: Lanexa soils are used mainly as wetland wildlife habitat. Native vegetation consists mostly of annual herbaceous plants. These include Arrow-arum, arrowhead, American waterlily, cattail, pickerelweed, and smartweeds. Woody vegetation includes scattered bald cypress, water tupelo, buttonbush, and groundsel-tree.
DISTRIBUTION AND EXTENT: Coastal Plain of Virginia and possibly North Carolina and Maryland. The soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: New Kent County, Virginia, 1985.
REMARKS: 1. These soil areas have been included with higher order units, swamps, and marshes in past mapping. 2. The diagnostic horizons and features recognized in this pedon are:
a) organic soil material - the zone from 15 to 40 inches (Oa horizon).
b) clayey family feature - The weighted average particle size of that part of the mineral soil within the control section (the zone from 40 to 51 inches).
ADDITIONAL DATA: Data for the site location (S81VA-127-009) are available from the NSSL, Lincoln, NE.
TABULAR SERIES DATA:
SOI-5 Soil Name Slope Airtemp FrFr/Seas Precip Elevation VA0239 LANEXA 0- 1 57- 62 190-210 40- 48 1- 3SOI-5 FloodL FloodH Watertable Kind Months Bedrock Hardness VA0239 FREQ 0-0.5 APPARENT JAN-DEC 60-60
SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC- VA0239 0-15 MK-SIL MK-SICL MK-SIC 0- 0 95-100 20-50 - VA0239 0-15 MUCK MPT 0- 0 - 0- 0 - VA0239 15-40 MUCK 0- 0 - 0- 0 - VA0239 40-60 SR MK-C 0- 0 95-100 35-60 -
SOI-5 Depth -pH- O.M. Salin Permeab Shnk-Swll VA0239 0-15 3.6- 6.5 12-22 4- 8 0.2- 2.0 LOW VA0239 0-15 3.6- 6.5 20-65 4- 8 0.6- 2.0 LOW VA0239 15-40 3.6- 6.5 20-65 2- 4 0.6- 2.0 LOW VA0239 40-60 3.6- 6.5 12-22 0- 2 0.0- 0.6 MODERATE