LOCATION ARMAGH PA+MD WVEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, mesic Typic Endoaquults
TYPICAL PEDON: Armagh silt loam - cropland, 3 to 8 percent slopes. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 8 inches; dark grayish brown (10YR 4/2) silt loam; weak fine granular structure; friable, slightly sticky, slightly plastic; many fine roots; 5 percent rock fragments; abrupt smooth boundary. (6 to 10 inches thick)
Eg--8 to 10 inches; light brownish gray (10YR 6/2) silt loam; many fine distinct strong brown (7.5YR 5/6) mottles; moderate medium subangular blocky structure; friable, slightly sticky, plastic; many fine roots; few faint clay films on faces of peds; few distinct black coatings; 8 percent rock fragments; very strongly acid; clear wavy boundary. (0 to 6 inches thick)
Btg1--10 to 15 inches; light brownish gray (10YR 6/2) silty clay loam; common medium distinct yellowish brown (10YR 5/4) and strong brown (7.5YR 5/6) mottles; moderate coarse prismatic structure parting to moderate medium blocky; firm, sticky, plastic; common faint clay films on faces of peds; few distinct black coatings on faces of peds; 8 percent rock fragments; very strongly acid; clear wavy boundary.
Btg2--15 to 24 inches; gray (N 6/0) silty clay; common medium distinct light olive brown (2.5Y 5/4) mottles and few fine prominent yellowish brown (10YR 5/8) mottles; moderate coarse prismatic structure parting to moderate medium blocky; firm, sticky, plastic; common faint clay films on faces of peds; few distinct black coatings on faces of peds; 8 percent rock fragments; very strongly acid; clear wavy boundary.
Btg3--24 to 29 inches; gray (10YR 5/1) silty clay, gray (N 6/0) face of peds; many medium distinct strong brown (7.5YR 5/6) mottles; moderate coarse prismatic structure parting to moderate coarse blocky; firm, slightly sticky, plastic; many prominent clay and silt coatings on faces of prisms; common distinct black coatings on faces of peds; 10 percent rock fragments; strongly acid; gradual wavy boundary.
Btg4--29 to 41 inches; gray (10YR 5/1) channery silty clay loam, gray (N 6/0) faces of peds; many medium distinct strong brown (7.5YR 5/6) mottles; moderate coarse prismatic structure parting to moderate coarse blocky; firm, slightly sticky, plastic; many prominent clay and silt coatings on face of prisms; common distinct black coatings on faces of peds; 20 percent rock fragments; strongly acid; clear wavy boundary. (Combined thickness of the B horizon is 24 to 34 inches.)
Cg--41 to 56 inches; brown (7.5YR 5/4) very channery silty clay loam, gray (10YR 6/1) face of peds; common medium distinct grayish brown (10YR 5/2) mottles; moderate very coarse prismatic structure; firm, slightly sticky, slightly plastic; 45 percent rock fragments; strongly acid.
TYPE LOCATION: Jefferson County, Pennsylvania; 3 miles south of Reynoldsville and 2 miles west of Sykesville, about 85 feet south and 440 feet west of the junction of routes 33051 and T509.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 30 to 50 inches. Depth to sandstone or shale bedrock is 40 to 72 inches. Rock fragments range from 0 to 15 percent in the upper part of the solum, 5 to 15 percent in the lower part of the solum, and 10 to 80 percent in the C horizon. Reaction is strongly or very strongly acid throughout unless limed. Kaolinite and illite are the dominant clay minerals with detectable amounts of chlorite and vermiculite.
The Ap horizon has hue of 10YR or 2.5Y, value of 3 through 5, and chroma of 1 or 2. Undisturbed A horizons are neutral or have hue of 10YR or 2.5Y, value of 2, and chroma of 0 through 2. It ranges from loam to silty clay loam in the fine-earth fraction.
The E horizon has hue of 10YR or 2.5Y, value of 4 through 6, and chroma of 1.
The Btg horizon is neutral or has hue of 7.5YR through 5Y, value of 4 through 7, and chroma of 0 through 2. It has distinct or prominent mottles. It ranges from silty clay loam to clay with channery analogues in the lower part. Clay content in some subhorizons is as high as 55 percent, but the weighted average is slightly above 35 percent.
The C horizon has hue of 7.5YR through 5Y, value of 5 or 6, and chroma of 1 through 8, and is mottled. It ranges from loam to silty clay in the fine-earth fraction.
COMPETING SERIES: The Elkton, Kinkora, and Purdy series are in the same family. Elkton soils do not have rock fragments in the lower part of the series control section. Purdy soils have less than 5 percent rock fragments in the lower part of the series control section. Kinkora soils are micaceous.
Baile, Brinkerton, Canadice, Cavode, Library, Prout, Shrewsbury, and Trumbull series are in related families. Baile, Brinkerton, and Shrewsbury soils have control sections with weighted average clay content of less than 35 percent. Cavode and Prout soils have a subhorizon between the A horizon and 30 inches which has more than 40 percent of the soil matrix with chroma of 3 or more. Canadice, Library, and Trumbull soils have base saturations higher than 35 percent.
GEOGRAPHIC SETTING: Armagh soils are on broad ridgetops and benches. Slopes range from 0 to 8 percent. These soils developed in materials weathered from acid gray shale, with some interbedded siltstone and sandstone. The mean annual precipitation ranges from 35 to 48 inches, and mean annual temperature ranges from 45 to 57 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: Armagh soils are in a drainage sequence with the moderately well drained Wharton soils and the somewhat poorly drained Cavode soils. Other associated soils include the Brinkerton, a competing series, the Gilpin soils which are well drained, and the Ernest soils which are moderately well drained, less clayey and have a fragipan.
DRAINAGE AND PERMEABILITY: Poorly drained. Runoff is slow and some areas are ponded during wet periods. Permeability is slow.
USE AND VEGETATION: About 35 percent of the area is in cropland, pasture, or is idle. The remaining 65 percent is in woodland consisting of mixed northern hardwoods dominantly in oaks, tulip poplar, and red maple.
DISTRIBUTION AND EXTENT: Appalachian Plateau of western Pennsylvania and western Maryland. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Clarion County, Pennsylvania, 1940.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
a. Ochric epipedon - the zone from the surface of the soil to a depth of about 10 inches (Ap and Eg horizons).
b. Argillic horizon - the zone from 10 to 41 inches (Btg horizon).
Classification only was changed in 11/94, competing series and other changes will be made later.