LOCATION WILPOINT           NY
Established Series
Rev. LMcD-JWW
3/88

WILPOINT SERIES


The Wilpoint series consists of moderately deep, moderately well drained soils formed in slowly or very slowly permeable clayey lacustrine sediments. They are gently sloping to sloping soils on bedrock controlled landforms. Wilpoint soils typically have dark grayish brown silty clay loam A horizons; mottled dark brown and dark grayish brown silty clay and clay B horizons, and dark gray clay C horizons overlying massive level bedded limestone bedrock.

TAXONOMIC CLASS: Very-fine, mixed, mesic Aquic Hapludalfs

TYPICAL PEDON: Wilpoint silt clay loam - idle. (Colors are for moist soils unless otherwise noted.)

Ap--0 to 6 inches; dark grayish brown (10YR 4/2) silty clay loam; strong medium granular structure; friable; hard many fine roots; slightly acid; abrupt smooth boundary. (5 to 10 inches thick)

Bt1--6 to 9 inches; dark brown (10YR 4/3) silty clay; common medium faint dark yellowish brown (10YR 4/4) mottles; moderate coarse subangular blocky structure; firm, slightly sticky and plastic: common fine roots; common large and medium pores with clay linings; thin brown (10YR 5/3) coatings on faces of peds; slightly acid; clear smooth boundary. (2 to 5 inches thick)

Bt2--9 to 16 inches; dark brown (10YR 4/3) clay; common fine distinct dark yellowish brown (10YR 4/4) and light brownish gray (10YR 6/2) mottles; moderate coarse prismatic structure parting to moderate medium subangular blocky; firm, sticky and plastic; common fine roots; many fine and medium, pores with clay linings; thick continuous clay skins on faces of peds; slightly acid; clear wavy boundary. ( 4 to 8 inches thick)

Bt3--15 to 22 inches; dark grayish brown (2.5Y 4/2) clay; common medium distinct dark yellowish brown (10YR 4/4) mottles; moderate coarse prismatic structure parting to weak fine blocky; firm, sticky and plastic; few fine roots; common medium and large pores with clay linings; thick continuous clay skins on faces of ped; calcareous in lower part; mildly alkaline; clear smooth boundary. (0 to 10 inches thick)

C--22 to 29 inches; dark gray (10YR 4/1) clay; common, medium distinct brown (7.5YR 4/4) mottles; massive; firm, sticky and slightly plastic; common fine and medium pores; common light gray (10YR 7/1) lime streaks; calcareous; moderately alkaline; abrupt smooth boundary. (2 to 10 inches thick)

2R--29 inches; massive level-bedded limestone bedrock.

TYPE LOCATION: Jefferson County, New York; Town of Cape Vincent, 30 meters south of Pleasant Valley Road, 15 meters east of Wilson Point Road.

RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 20 to 40 inches. Coarse fragments are commonly lacking in the A and B horizons but range up to 5 percent in some pedons. Reaction is medium acid to neutral in the A and B horizons and neutral to moderately alkaline in the Bt, if present, and the C. The C horizon contains free carbonates.

The A horizon has hue of 10YR or 2.5Y, value of 3 or 4, and chroma of 2 or 3. Texture is silty clay loam or silty clay. It has moderate or strong, very fine to coarse granular or blocky structure. Consistence is friable or firm.

The B horizon has hue of 10YR through 5Y, value of 3 to 5, and chroma of 2 to 4 and is mottled. Chroma of 2 is lithochromic and not indicative of wetness. Texture is clay with thin silty clay subhorizons with average clay content of 60 percent or more. It has moderate or strong, very fine to coarse, angular or subangular blocky structure or primary structure is prismatic parting to blocky. Consistence is friable or firm, sticky or firm, sticky or very sticky and plastic or very plastic.

BC or C horizons have hue of 10YR through 5Y, value of 3 to 5, and chroma of 1 to 3. The B horizon has blocky or subangular blocky structure. The C horizon is massive or has coarse prismatic structure. Texture is clay or silty clay.

COMPETING SERIES: There are no other series in the same family. Similar soils in related families are the Broughton, Chaumont, Covington, Guffin, Kingsbury, Livingston, and Vergennes. Broughton, Covington, Kingsbury, Livingston and Vergennes soils are more than 1 meter deep to bedrock and have illitic mineralogy. Chaumont soils have argillic horizons that are dominated by colors with chroma of 2. Guffine soils have aquic moisture regimes, lack argillic horizons and are dominated by 2 chroma colors throughout.

GEOGRAPHIC SETTING: Wilpoint are gently sloping to sloping soils with slopes ranging from 3 to 15 percent. The Wilpoint soils are on convex landscapes where relatively thin clayey marine sediments overlie hard bedrock. The bedrock is primarily limestone with some areas underlain by granite, sandstone or shale. Mean annual air temperature ranges from 47 to 50 degrees F; mean annual precipitation ranges from 30 to 44 inches and mean annual growing season from 120 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the somewhat poorly drained Chaumont and the poorly drained and very poorly drained Guffin soils which are in a drainage sequence with Wilpoint and the competing Covington, Kingsbury, Livingston and Vergennes soils. Also associated are the Benson, Newstead and Rhinebeck soils. Benson and Newstead are shallow and moderately deep soils occurring on adjacent bedrock controlled till landscapes. Rhinebeck soils are deep soils developed in lacustrine materials that contain slightly smaller amounts of clay.

DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is moderate to rapid. Permeability is slow or very slow. A seasonal high water table is at depths of 18 to 24 inches below the surface from December to May.

USE AND VEGETATION: Cleared areas are used to grow corn, small grain and hay in support of dairy farming. Native vegetation is white cedar, sugar maple, white ash, oaks, white pine, and hemlock.

DISTRIBUTION AND EXTENT: St. Lawrence Valley of New York and possibly the Champlain Lowlands of New York and Vermont. The series is believed to be moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Amherst, Massachusetts

SERIES ESTABLISHED: Jefferson County, New York, 1983. Source of the name is a point of land (Wilson Point) in eastern Lake Ontario.

REMARKS: This draft changes the classification of the Wilpoint series from very fine, illitic, mesic Glossaquic Hapludalfs to very fine, mixed, mesic Aquic Hapludalfs. Investigations have shown that the A part of the upper part of the B horizon has chroma that is too high and thickness that is less than 1 millimeter thick on abutting ped surfaces. Mineralogy is changed based on samples from the closely associated Chaumont and Guffin soils.


National Cooperative Soil Survey
U.S.A.