LOCATION COHAS NHEstablished Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, active, nonacid, frigid Aeric Endoaquepts
TYPICAL PEDON: Cohas loam, on a 1 percent west-facing slope, in a grass-legume hayfield. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; very dark grayish brown (10YR 3/2) loam, pale brown (10YR 6/3) dry; weak coarse granular structure; friable; common very fine and fine roots; few medium prominent strong brown (7.5YR 5/8) masses of iron accumulation; slightly acid; abrupt smooth boundary. (5 to 11 inches thick)
Bw--8 to 15 inches; light olive brown (2.5Y 5/4) very fine sandy loam; massive; friable; common very fine and fine roots; common medium prominent reddish brown (5YR 4/4) and brown (7.5YR 5/4) masses of iron accumulation, and common medium distinct pale olive (5Y 6/3) iron depletions; moderately acid; abrupt smooth boundary.
Bg--15 to 18 inches; grayish brown (2.5Y 5/2) very fine sandy loam; massive; friable; common very fine and fine roots; many medium prominent yellowish brown (10YR 5/4) masses of iron accumulation; strongly acid; abrupt smooth boundary. (Total thickness of the B horizons is 9 to 24 inches.)
2C1--18 to 23 inches; olive brown (2.5Y 4/4) sand; massive; very friable; common very fine and fine roots; 3 percent gravel; common medium prominent yellowish red (5YR 4/6) and common medium faint light olive brown (2.5Y 5/4) masses of iron accumulation; strongly acid; abrupt smooth boundary.
2C2--23 to 35 inches; variegated dusky red (2.5YR 3/2), light olive brown (2.5Y 5/4), and yellowish red (5YR 4/6) extremely gravelly coarse sand; single grain; loose; continuous dusky red (2.5YR 3/2) moderately thick iron-manganese coatings on pebbles; 56 percent gravel, 10 percent cobbles; strongly acid; abrupt smooth boundary.
2C3--35 to 65 inches; variegated grayish brown (2.5Y 5/2), strong brown (7.5YR 5/6), and yellowish brown (10YR 5/6) extremely gravelly coarse sand; single grain; loose; continuous strong brown (7.5YR 5/6) moderately thick iron-manganese coatings on pebbles; 55 percent gravel, 15 percent cobbles; slightly acid.
TYPE LOCATION: Coos County, New Hampshire; Town of Lancaster, 1100 feet east northeast of the confluence of Burnside and Whipple Brooks; latitude 44 degrees 30 minutes 13 seconds North, longitude 71 degrees, 30 minutes, 57 seconds West, NAD 83.
RANGE IN CHARACTERISTICS: Depth to the contrasting material ranges from 15 to 35 inches. Rock fragments range from 0 to 5 percent in the loamy sediments, and from 0 to 75 percent in individual horizons in the contrasting material with a weighted average of 35 percent or more within 40 inches from the surface. Reaction ranges from very strongly acid through slightly acid.
The Ap or A horizon has hue of 10YR to 5Y and chroma of 1 or 2. The value is 3 or 4 moist. Texture is loam, silt loam, very fine sandy loam, or fine sandy loam. Structure is fine, medium, or coarse granular. Consistence is friable or very friable.
The Bw horizon has hue of 10YR to 5Y, value of 4 to 6, and chroma of 3 or 4. Texture is silt loam, very fine sandy loam, or fine sandy loam. Structure is weak fine granular, or the horizon is massive.
The Bg horizon is neutral or has hue of 10YR to 5Y, value of 4 to 6, and chroma of 0 to 2. Texture is silt loam, very fine sandy loam, or fine sandy loam. Structure is weak fine granular, or the horizon is massive.
The 2C horizon is neutral or has hue of 2.5YR to 5Y, value of 3 to 8, and chroma of 0 to 8. Texture ranges from fine sand to coarse sand in the fine-earth fraction.
COMPETING SERIES: There are currently no other series in this family. The similar Grange series is superactive.
GEOGRAPHIC SETTING: Cohas soils are on nearly level alluvial terraces of small, gravel-bottom rivers and brooks. Mean annual temperature ranges from 40 to 45 degrees F. Mean annual precipitation ranges from 35 to 50 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Abenaki, Colton, Metallak, and Rumney series. The well drained Abenaki and the moderately well drained Metallak soils are in a drainage sequence with Cohas soils, and are in higher positions on alluvial terraces. Colton soils have spodic horizons and are on adjacent glacial outwash terraces. Rumney soils are in similar positions on the landscape, have a coarse-loamy particle-size control section, and have organic matter content decreasing irregularly with depth.
DRAINAGE AND PERMEABILITY: Cohas soils are poorly drained. Permeability is moderate in the loamy sediments and rapid or very rapid in the underlying contrasting material. Potential for surface runoff is low.
USE AND VEGETATION: About half of the acreage is in pasture or hayland. The remaining acreage is forested with balsam fir, alders, white spruce, and eastern white pine.
DISTRIBUTION AND EXTENT: New Hampshire and New York; MLRAs 143 and 144B. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Amherst, Massachusetts.
SERIES ESTABLISHED: Coos County, New Hampshire, 1999.
REMARKS: 1. The classification is updated to the 2nd edition of Soil Taxonomy with this revision. The previous classification was coarse-loamy over sandy or sandy-skeletal, mixed, active, nonacid, frigid Aeric Endoaquents
2. Diagnostic horizons and features recognized in the typifying pedon are:
a. Ochric epipedon - the zone from 0 to 8 inches (Ap horizon).
b. Cambic horizon - the zone from 8 to 18 inches (Bw and Bg horizon).
c. Strongly contrasting particle size class - the zone from 10 to 18 inches is coarse-loamy and has less than 50 percent fine sand or coarser, and the zone from 18 to 40 inches is sandy-skeletal.
ADDITIONAL DATA: NSSL data is available for this pedon: S83NH-7-16.