LOCATION DUNKIRK NYEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Glossic Hapludalfs
TYPICAL PEDON: Dunkirk silt loam on a 6 percent slope in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap-- 0 to 6 inches; dark grayish brown (10YR 4/2) silt loam; weak medium and fine granular structure; friable; many fine roots; strongly acid; abrupt smooth boundary. (6 to 10 inches thick.)
EB-- 6 to 11 inches; yellowish brown (10YR 5/4) silt loam; weak fine subangular blocky structure; very friable; many fine roots; common medium pores; strongly acid; gradual wavy boundary. (0 to 12 inches thick.)
E/B-- 11 to 14 inches; brown (10YR 5/3) silt loam; weak fine subangular blocky structure; friable; common fine roots; common medium pores with faint patchy clay films on surfaces along pores; 30 percent brown (7.5YR 4/4) ped interiors; strongly acid; clear wavy boundary. (0 to 6 inches thick.)
B/E-- 14 to 17 inches; brown (7.5YR 4/4) silt loam; moderate medium subangular blocky structure; firm; common fine roots; common fine and medium pores; grayish brown (10YR 5/2) ped faces 1 to 2 millimeters thick which constitutes less than 15 percent by volume; common clay films on surfaces along pores; moderately acid; gradual wavy boundary. (2 to 6 inches thick.)
Bt1-- 17 to 20 inches; brown (7.5YR 4/4) silt loam; moderate medium subangular blocky structure; firm; common fine roots; common medium pores; distinct clay films on surfaces along pores; common distinct patchy clay films on all faces of peds; moderately acid; gradual wavy boundary.
Bt2-- 20 to 36 inches; brown (10YR 4/3) silt loam; moderate coarse subangular blocky structure; firm; few fine roots; common medium and large pores; common distinct clay films on surfaces along pores; many distinct clay films on all faces of peds; slightly acid; gradual wavy boundary. (Combined thickness of the Bt horizon is 10 to 34 inches.)
C1-- 36 to 42 inches; brown (10YR 4/3) silt loam with thin layers of very fine sandy loam; massive within inherited varves; friable; few fine roots; neutral; clear wavy boundary.
C2-- 42 to 72 inches; dark grayish brown (10YR 4/2) layers (varves) of silt and very fine sand; friable; moderately alkaline; strongly effervescent.
TYPE LOCATION: Genesee County, New York; Town of Alexander, 0.35 miles north of U.S. Route 20, east of Brookville Road, and 1-1/8 miles northeast of the Village of Alexander. USGS Batavia South, NY topographic quadrangle; Latitude 42 degrees, 54 minutes, 16 seconds N. and Longitude 78 degrees, 14 minutes, 09 seconds W., NAD 1927.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 20 to 48 inches. Depth to carbonates ranges from 20 to 54 inches. Rock fragments, mainly gravel and cobbles, range from none to 5 percent throughout the soil. Depth to bedrock is greater than 60 inches.
The Ap or A horizon has hue of 7.5YR through 2.5Y, value of 3 through 5 and chroma of 2 through 4. It is silt loam, very fine sandy loam or fine sandy loam. The horizon is friable or very friable, and reaction ranges from strongly acid to slightly acid, unless limed.
The EB horizon has hue of 7.5YR through 2.5Y, value of 5 or 6, and chroma of 3 through 5. It ranges from silt loam to fine sandy loam. Structure is subangular blocky or platy, and consistence is friable or very friable. Reaction ranges from strongly acid to neutral.
Some pedons have an E horizon with value of 5 through 7 and chroma of 2 or 3. Texture is similar to the EB horizon.
The E/B and B/E horizon have color and texture similar to the respective portion of the E or EB and Bt horizon above and below.
The Bt horizon has hue of 5YR to 2.5Y, value of 3 through 5 and chroma from 2 through 4, with the lowest chroma being inherited from weathered dark shale. Texture is silt loam, very fine sandy loam, or silty clay loam. In some pedons, the Bt horizon has faint redoximorphic features in the lower part. Consistence is friable or firm. Reaction ranges from moderately acid to slightly alkaline.
Some pedons have a BC horizon that is slightly acid to moderately alkaline and has a lower clay content than the overlying Bt horizon.
The C horizon has colors similar to the Bt horizons. Texture ranges from very fine sand or silt to silty clay loam, some pedons having thin strata of finer or coarser texture including sand and gravel below depths of 4 feet. Reaction ranges from slightly acid to moderately alkaline.
COMPETING SERIES: The Dunkirk soil is the only series in the same family.
The Allard, Amboy, Collamer, Hudson, and Unadilla series are similar soils in related families. Allard, Amboy, and Unadilla soils have less than 18 percent clay in the particle-size control section. Collamer soils have distinct or prominent redoximorphic features in the upper part of the B horizons. Hudson soil have more than 35 percent clay in the B horizon.
GEOGRAPHIC SETTING: Dunkirk soils developed in glacio-lacustrine deposits dominated by silt, very fine sand, and clay. These soils are on lake plains and along lower valley sides in major valleys. Slope ranges from 0 to 60 percent, with the more sloping areas being prominently dissected. Surface shape is convex. Mean annual air temperature ranges from 45 to 52 degrees F., mean annual precipitation ranges from 26 to 44 inches, and the growing season is from 130 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Allard, Amboy, Arkport, Canandaigua, Collamer, Honeoye, Howard, Hudson, Madrid, Niagara, Ontario, Palmyra, and Unadilla soils. Allard, Amboy, Arkport, Colonie, Hudson, and Unadilla soils are associated on nearby lake-plain landscapes but lack a fine-silty particle size control section. Moderately well drained, Collamer soils, somewhat poorly drained Niagara soils, and poorly and very poorly drained Canandaguia soils form a drainage sequence with Dunkirk soils. Honeoye, Madrid and Ontario soils formed in glacial till on associated uplands. Howard and Palmyra soils formed in glacial outwash deposits on nearby terraces.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. The potential for surface runoff is medium or very high. Saturated hydraulic conductivity is moderately high or high in the mineral surface and sub-surface layers and moderately low to high in the subsoil and substratum.
USE AND VEGETATION: Most areas have been cleared, and are used for growing corn, small grain, hay, and pasture. Vegetable crops and orchards are also important. Native vegetation is sugar maple, beech, oaks, hickories, black cherry, white ash, and white pine.
DISTRIBUTION AND EXTENT: The Erie and Ontario lake plains of New York, and to a minor extent, the Mohawk and Hudson Valleys and broad valleys of the Allegheny Plateau of New York. MLRAs 101, 139, 140, 142, and 144A. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Amherst, Massachusetts
SERIES ESTABLISHED: Chautauqua County, New York,
REMARKS: Diagnostic horizons and other features recognized in the typical pedons are:
(1) Ochric epipedon - the zone from the surface to a depth of 11 inches (Ap and EB horizons).
(2) Glossic character - as evidenced by interfingers in the zone from 11 to 17 inches (E/B and B/E horizons).
(3) Argillic horizon - the zone from 14 to 36 inches (B/E and Bt horizons).