LOCATION DUNCANNON PA+OH WVEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, active, mesic Ultic Hapludalfs
TYPICAL PEDON: Duncannon silt loam - idle cropland (Colors are for moist soil unless otherwise stated.)
Ap--0 to 10 inches; brown (10YR 4/3) silt loam; weak fine granular structure; friable, slightly sticky, nonplastic; 1 percent shale fragments; strongly acid; abrupt wavy boundary.(6 to 12 inches thick)
BA--10 to 17 inches; yellowish brown (10YR 5/4) silt loam; weak fine subangular blocky structure; friable, slightly sticky, slightly plastic; moderately acid; clear wavy boundary. (0 to 8 inches thick)
Bt1--17 to 24 inches; brown (7.5YR 4/4) silt loam; weak medium subangular blocky structure; friable, slightly sticky, slightly plastic; few thin clay films on faces of peds; 1 percent shale; moderately acid; gradual wavy boundary. (5 to 15 inches thick)
Bt2--24 to 34 inches; brown (7.5YR 4/4) silt loam; weak medium subangular blocky structure; friable, slightly sticky, slightly plastic; few thin clay films on faces of peds; 5 percent shale; moderately acid; gradual wavy boundary. (8 to 18 inches thick)
BC--34 to 45 inches; brown (7.5YR 4/4) silt loam; weak thick platy structure; friable, slightly sticky, slightly plastic; few thin clay films in pores; moderately acid; abrupt wavy boundary. (10 to 20 inches thick)
2C1--45 to 49 inches; brown (7.5YR 4/4) channery silt loam, with common medium distinct yellowish red and brown lithochromic mottles; weak medium platy structure; friable, slightly sticky, slightly plastic; few thin clay films in pores; 20 percent shale fragments; moderately acid; abrupt wavy boundary. (4 to 16 inches thick)
2C2--49 to 56 inches; brown (7.5YR 4/2) channery silt loam; weak thin platy structure; friable, slightly sticky, slightly plastic; few thin clay films in pores; 20 percent shale fragments; moderately acid; clear wavy boundary. (0 to 15 inches thick)
2C3--56 to 68 inches; dark reddish brown (5YR 3/3), with thin bands of yellowish brown (10YR 5/8), channery silt loam; weak thin platy structure; friable, slightly sticky, slightly plastic; 20 percent shale fragments; strongly acid.
TYPE LOCATION: Bucks County, Pennsylvania; 4 1/2 miles northeast of Newtown near the Mount Eyre Road, approximately 220 feet north of stone garage.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to 60 inches or more, but the argillic horizon terminates within 40 inches. Depth to bedrock is greater than 5 feet. The silt loam to very fine sandy loam mantle is 40 to 70 inches thick and contains up to 10 percent shale or gravel. Nonconforming BC and C horizons contain 15 to 50 percent shale fragments or gravel. Reaction, where unlimed, is very strongly to moderately acid in the solum, and slightly to strongly acid in the C horizon.
The Ap or A horizon has hue of 10YR, with value of 3 through 5 and chroma of 2 through 4. Textures are silt loam, loam or very fine sandy loam.
The BA and Bt horizons have hues of 7.5YR or 10YR, with value of 4 or 5 and chroma of 2 to 8. They are silt loam, loam or very fine sandy loam, with a weighted average of less than 15 percent fine sand and coarser particles. Clay content of individual horizons of the Bt ranges from 10 to 24 percent, with a weighted average of less than 18 percent. Structure is weak to moderate, fine or medium subangular blocky. Some pedons have prismatic structure in the lower part of the B horizon. They have few to common thin clay films on ped faces or lining pores. Some pedons have 2BC horizons occurring below 40 inches that have fine earth textures of silt loam, loam or sandy loam.
The C and 2C horizons are yellowish brown to dusky red with hue of 10YR to 10R. Faint to distinct redoximorphic features or lithochromic mottles commonly occur in the C horizon. Textures are silt loam or very fine sandy loam above the lithologic discontinuity, and silt loam, loam or sandy loam below.
COMPETING SERIES: The Duncannon series is the only recognized series in the family. The Bucks, Elk, Unadilla and Wellston series are in other related families. Bucks, Elk and Wellston soils have more than 18 percent clay in the particle-size control section. Unadilla soils lack an argillic horizon.
GEOGRAPHIC SETTING: These soils are on nearly level to moderately steep uplands and terraces. The soils formed in silty to very fine sandy loam material, presumed to be eolian, overlying a variety of materials of shale, sandstone, limestone, schist, stream deposits and glacial deposits. Slope ranges from 0 to 35 percent. Climate is continental with warm summers and cold winters. Rainfall averages 35 to 48 inches and is evenly distributed throughout the year. Average annual air temperature is 50 degrees to 60 degrees F. and the frost free season is 150 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: Duncannon is the well drained member of a drainage sequence that includes the moderately well drained Lawrenceville, the somewhat poorly drained Chalfont and the poorly drained Doylestown soils. The competing Bucks and the Abbottstown, Chester, Croton, Gilpin, Lansdale, Penn, Readington, Raritan, Upshur, Wellston and Zanesville soils are on various nearby landforms. Abbottstown, Croton, Readington, Raritan and Zanesville soils have fragipans. Chester, Gilpin, Penn, and Upshur soils have more than 18 percent clay in the particle-size control section. Gilpin and Penn soils also have shale bedrock within 40 inches. Lansdale soils have loamy textures containing more than 15 percent sand coarser than very fine sand.
DRAINAGE AND PERMEABILITY: Well drained. The potential for surface runoff potential is medium. Permeability is moderate.
USE AND VEGETATION: Most areas have been cleared of trees and are being used for cropland, hay and pasture. Wooded areas are mixed hardwoods composed principally of upland oaks, yellow poplar and
ash.
DISTRIBUTION AND EXTENT: Pennsylvania, western West Virginia, and southeastern Ohio. It is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Perry County, Pennsylvania; 1951.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
a. Ochric epipedon - the zone from 0 to 10 inches (Ap horizon).
b. Argillic horizon - the zone from 17 to 34 inches (Bt1 and Bt2 horizons).
Laboratory data are available for two pedons, S68Pa-09-4 (1-8) and S68Pa-09-5 (1-8), sampled in Bucks County, Pennsylvania.