LOCATION BRECKNOCK PA+MD VAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ultic Hapludalfs
TYPICAL PEDON: Brecknock channery silt loam--on 3 to 8 percent east facing slopes in a cultivated field. (Colors are for moist soils unless otherwise noted.)
Ap--0 to 8 inches; very dark grayish brown (10YR 3/2) channery silt loam, light brownish gray (10YR 6/2) dry; moderate fine granular structure; friable, slightly sticky, slightly plastic; 15 percent rounded gravel; neutral; abrupt smooth boundary. (6 to 10 inches thick)
Bt1--8 to 20 inches; dark grayish brown (2.5Y 4/2) silt loam; weak medium subangular blocky structure; friable, slightly sticky, slightly plastic; common distinct clay films on faces of peds; 10 percent rounded gravel; slightly acid; clear smooth boundary. (5 to 15 inches thick)
Bt2--20 to 28 inches; dark grayish brown (2.5Y 4/2) silt loam; moderate medium subangular blocky structure; firm, slightly sticky, slightly plastic; common distinct clay films on all faces of peds; and few distinct black coatings of iron-manganese on faces of peds; 10 percent rounded gravel; moderately acid; clear smooth boundary. (6 to 14 inches thick)
BC--28 to 36 inches; dark grayish brown (10YR 4/2) channery silt loam; weak medium subangular blocky structure; firm, slightly sticky, slightly plastic; common distinct black iron-manganese coatings on faces of peds; 15 percent rounded gravel; moderately acid; clear smooth boundary. (4 to 12 inches thick)
C--36 to 46 inches; very dark gray (10YR 3/1) very channery silt loam; weak medium subangular blocky rock structure; firm slightly sticky, slightly plastic; 40 percent rounded gravel; strongly acid; clear wavy boundary. (8 to 24 inches thick)
R--46 inches; dark gray (10YR4/1) to dark bluish gray porcelanite.
TYPE LOCATION: Lebanon County, Pennsylvania, South Londonderry Township, 1-1/2 miles northeast of Upper Lawn on PA 117 to intersection of T331 600 feet east of intersection.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 24 to 40 inches. Depth to bedrock is 40 to 60 inches. Rock fragments of porcelanite and hornfels channers range from 5 to 35 percent in the solum and from 15 to 70 percent in the C horizon. Reaction, unless limed, ranges from very strongly acid through slightly acid throughout the soil. Kaolinite, illite and vermiculite are the dominant minerals of the clay fraction with detectable amounts of chlorite and interstratified clays.
The A or Ap horizon has hue of 10YR or 2.5Y, value of 3 or 4, and chroma of 2 or 3. Value of 2 and chroma of 1 are permitted in undisturbed pedons. Fine-earth texture is loam or silt loam.
Undisturbed pedons have E horizons with hue of 10YR or 2.5Y, value of 4 or 5 and chroma of 2 or 3. Fine earth texture is loam or silt loam.
The B horizon has hue of 10YR through 5Y, value of 3 through 5, and chroma of 2 through 4. Fine-earth textures are loam, silt loam, clay loam, and silty clay loam.
The C horizon has hue of 10YR through 5B, value of 3 through 5, and chroma of 1 through 4. Fine-earth texture is loam, silt loam, and clay loam.
COMPETING SERIES: Caribel, Fredericktown, Neshaminy, Penn and Weedmark are in the same family. Caribel series consists of very deep soils formed in material weathered from basalt. The Fredericktown soils formed in stratified outwash deposits, mainly of sandstone and shale with a large amount of igneous gravel with or without a thin loess mantle and are on treads and risers on stream terraces. Neshaminy, soils have bedrock at a depth of more than 5 feet and formed on diabase. Penn soils have bedrock between 20 and 40 inches and formed in materials weathered from noncalcareous reddish shale, siltstone, and fine-grained sandstone normally of Triassic age. The Weedmark soils are moderately deep or deep to a lithic contact and formed in residuum from gneiss schist, granite and other similar bedrock.
GEOGRAPHIC SETTING: Brecknock soils are on nearly level to very steep convex slopes of upland hills and low ridges. They formed in residuum weathered from metamorphosed red shale and sandstone (porcelanite). Climate is humid and temperate with mean annual temperature of 50 to 55 degrees F.; mean annual precipitation ranges from 40 to 48 inches; and the growing season ranges from 165 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: The Bucks, Croton, Joanna, Lehigh, Montalto, Mount Lucus, Neshaminy, Penn and Watchung, soils are on the same or nearby landscapes. Bucks and Montalto soils have hues of 7.5YR or redder in the Bt horizon. Croton and Watchung soils are poorly drained and are on lower landscape positions. Lehigh and Mount Lucus soils are moderately well drained and somewhat poorly drained and are on slightly lower landscape positions. Joanna soils are formed in residuum from interbedded Triassic red sandstone and conglomerate containing quartz pebbles
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. Runoff is slow to very rapid. Saturated hydraulic conductivity is moderately high.
USE AND VEGETATION: Approximately 55 percent of the Brecknock soils are in cropland or pasture, 40 percent is wooded, mostly mixed hardwoods, and 5 percent is in non-agricultural uses.
DISTRIBUTION AND EXTENT: Pennsylvania, New Jersey, and Virginia. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Lancaster County, Pennsylvania, 1937.
REMARKS: Diagnostic horizons and other features recognized in this pedon are:
a. Ochric epipedon - the zone from the surface of the soil to a depth of about 8 inches (Ap horizon).
b. Argillic horizon - the zone from 8 to 28 inches (Bt horizon).
2007 revises profile description and competing as well as geographically associated soils. Prior revision 6/2001.