Established Series


The Wegatchie series consists of very deep, poorly drained soils formed in silty glacial lake deposits. They are in level or depressional areas on lake plains and in basins on uplands. Slope ranges from 0 to 3 percent. Mean annual temperature is 43 degrees F., and mean annual precipitation is 38 inches.

TAXONOMIC CLASS: Fine-silty, mixed, active, nonacid, frigid Mollic Endoaquepts

TYPICAL PEDON: Wegatchie silt loam, on a 1 percent west-facing slope in a meadow. (Colors are for moist soil unless otherwise noted.)

Ap-- 0 to 8 inches; very dark gray (10YR 3/1) silt loam, grayish brown (10YR 5/2) dry; weak medium and coarse subangular blocky structure parting to fine and medium granular; friable; slightly sticky; common fine and few medium roots; few fine prominent dark brown (7.5YR 3/4) masses of iron accumulation; neutral; abrupt smooth boundary. (6 to 9 inches thick.)

Bg1-- 8 to 13 inches; gray (10YR 5/1) clay loam; moderate fine and medium subangular blocky structure; friable; common fine roots; common fine tubular and vesicular pores; few macropores; few faint silt coats on faces of peds; common fine faint grayish brown (2.5Y 5/2) and light brownish gray (2.5Y 6/2) areas of iron depletions, and many fine and medium prominent brown (7.5YR 4/4) masses of iron accumulation; neutral; abrupt smooth boundary.

Bg2-- 13 to 19 inches; dark gray (10YR 4/1) silty clay loam, gray (10YR 5/1) faces of peds; moderate very fine, fine and medium angular blocky structure; friable; few fine roots; common fine vesicular and tubular pores; few macropores; few faint silt coats on faces of peds; many fine and medium prominent brown (7.5YR 5/4) and strong brown (7.5YR 4/6) masses of iron accumulation; neutral; abrupt smooth boundary. (The combined thickness of the Bg horizon is 8 to 26 inches.)

BCg-- 19 to 40 inches; dark gray (10YR 4/1) silt loam, grayish brown (10YR 5/2) faces of peds; moderate coarse prismatic structure; firm; few fine roots on faces of prisms; many fine and medium tubular and vesicular pores; common fine prominent strong brown (7.5YR 5/8) and many medium prominent yellowish brown (10YR 5/6) masses of iron accumulation; slightly alkaline; abrupt smooth boundary. (0 to 27 inches thick.)

C-- 40 to 72 inches; yellowish brown (10YR 5/6) silt loam; weak medium plates breaking along depositional planes; firm; many medium distinct gray (10YR 6/1) silt loam varves; 10 percent rock fragments; slightly effervescent, slightly alkaline.

TYPE LOCATION: St. Lawrence County, New York; Town of Hammond, 40 feet west of Oak Point Road and 4200 feet south of the junction of Oak Point Road and River Road. USGS Morristown, NY topographic quadrangle; Latitude 44 degrees, 30 minutes, 00 seconds, N. and Longitude 75 degrees, 44 minutes, 30 seconds W. NAD 1927.

RANGE IN CHARACTERISTICS: The thickness of the solum ranges from 20 to 40 inches. Bedrock is at depths greater than 60 inches. The depth to carbonates ranges from 20 to 60 inches. Rock fragments, mostly gravel, range from 0 to 2 percent by volume in the solum and from 0 to 10 percent in the C horizon. Unless limed, reaction ranges from moderately acid through neutral in the surface layer, from slightly acid through slightly alkaline in the subsoil, and from neutral through moderately alkaline in the substratum.

The Ap horizon is neutral or has hue of 10YR, value of 2 or 3, and chroma of 0 through 2. Texture of the fine-earth fraction is silt loam, very fine sandy loam, or loam.

The B horizon is neutral or has hue of 7.5YR through 2.5Y, value of 4 through 6, and chroma of 0 through 2. Texture of the fine-earth fraction is silt loam, silty clay loam, clay loam, or very fine sandy loam.

The BC horizon is neutral or has hue of 7.5YR through 5Y, value of 4 or 5, and chroma of 0 through 2. Texture of the fine-earth fraction is similar to the B horizon.

The C horizon has hue of 7.5YR through 5Y, value of 3 through 6, and chroma of 1 through 6. Chroma of 3 through 6 is restricted to depths greater than 30 inches. Texture of the fine-earth fraction is very fine sandy loam, silt loam, clay loam, or silty clay loam and it is commonly varved.

COMPETING SERIES: There are no other series in the same family.

GEOGRAPHIC SETTING: Wegatchie soils are on glacial lake plains that have a plane or concave surface. The slope ranges from 0 to 3 percent. The mean annual temperature ranges from 38 to 45 degrees F.; mean annual precipitation ranges from 34 to 50 inches; and the frost-free period ranges from 100 to 150 days. Elevation ranges from 100 to 2000 feet above sea level.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Depeyster and Hailesboro soils, and Adjidaumo, Depeyster, Munuscong, Malone, Insula, and Summerville soils. The moderately well drained Depeyster soils and somewhat poorly drained Hailesboro soils are drainage associates on slightly higher landscape positions. Adijidaumo occupies similar landscape positions but has a fine particle-size control section. Malone soils are nearby but have a higher rock fragment content. The Munuscong soils are on similar landscape positions but are in a coarse-loamy over clayey family. The Insula and Summerville soils are shallow to bedrock and are on nearby bedrock controlled ridges.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained. The potential for surface runoff is negligible, high, or very high. Saturated hydraulic conductivity in the mineral soil surface and subsurface layers is moderately high or high. It is moderately low to high in the subsoil and substratum.

USE AND VEGETATION: Many areas of Wegatchie soils are in meadow. Some areas are in woodland, early stages of forest succession, or wild pasture. Common trees in wooded areas include: red maple, white ash, northern white-cedar, elm, eastern hemlock, and aspen.

DISTRIBUTION AND EXTENT: The St. Lawrence Lowlands and Champlain Valley of northern New York and possibly Vermont. MLRA 142 and 143. The series is of small extent.


SERIES ESTABLISHED: St. Lawrence County, New York, 1990.

REMARKS: 1). Originally Wegatchie was classified in the great group of Haplaquolls. Because of changes established in the 6th edition of `Keys to Soil Taxonomy' this soil now classifies in the new great group of Endoaquepts. Competing series may change as similar soils are reclassified.

2). Very poorly drained has been removed from the range of this series. Use of mucky modifiers in the A horizon and thin O horizons above the A are dropped.

3). Diagnostic horizons and features recognized in this pedon are:
a). Cambic horizon - the zone from 8 to 40 inches (Bg1, Bg2, And BCg horizon).
b). Mollic subgroup - has an Ap horizon with value of 3 or less moist, and 5 or less dry; and Ap layer is less than 10 inches thick.

National Cooperative Soil Survey