LOCATION PENLAW PA+MDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, semiactive, mesic Aquic Fragiudalfs
TYPICAL PEDON: Penlaw silt loam - cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 10 inches; dark grayish brown (10YR 4/2) silt loam; weak fine granular structure; friable, slightly sticky, slightly plastic; slightly acid; abrupt smooth boundary. (6 to 12 inches thick)
Bt--10 to 23 inches; yellowish brown (10YR 5/4) silty clay loam; moderate medium blocky structure; firm, slightly sticky, plastic; common faint clay films on faces of peds; common fine faint grayish brown (10YR 5/2) iron depletion; neutral; clear wavy boundary. (8 to 18 inches thick)
Bx1--23 to 35 inches; yellowish brown (10YR 5/6) silty clay loam; weak very coarse prismatic structure parting to moderate medium platy; firm, brittle, slightly sticky, and plastic; many distinct clay films and black coatings on faces of peds; many medium distinct brown (10YR 5/3) masses of oxidized iron and light gray (10YR 7/1) iron depletion; neutral; gradual wavy boundary. (10 to 20 inches thick)
Bx2--35 to 50 inches; yellowish brown (10YR 5/6) silty clay loam; weak very coarse prismatic structure parting to moderate medium blocky and medium and thick platy; firm, brittle, slightly sticky, plastic; common faint clay films and few black coatings on faces of peds; many medium distinct light brownish gray (10YR 6/2) iron depletion and strong brown (7.5YR 5/6) masses of oxidized iron; neutral; gradual wavy boundary. (8 to 20 inches thick)
C--50 to 61 inches; brown (10YR 4/3) silty clay; moderate medium blocky structure; firm, sticky, plastic; common medium distinct yellowish brown (10YR 5/6) masses of oxidized iron and grayish brown (10YR 5/2) iron depletion; 5 percent limestone pebbles; neutral.
TYPE LOCATION: Franklin County, Pennsylvania; Peters Township, 1.6 miles south of Lemasters, 1200 feet south of intersection of route T332 and 28065, 400 feet east of road culvert.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 40 to 60 inches. Depth to fragipan ranges from 15 to 30 inches. Depth to bedrock ranges from 40 to 72 inches or more. Rock fragments of chert, weathered limestone, shale or rarely, sandstone range from 0 to 10 percent above the fragipan, from 0 to 30 percent in the fragipan and C horizon. Reaction ranges from moderately acid to neutral throughout the soil.
The Ap horizon has hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 2 or 3. Some pedons have a BA horizon. Texture is silt loam in the fine- earth fraction.
The Bt horizon has hue of 10YR or 7.5YR, value of 5 or 6, and chroma of 2 through 8. Mottles with chroma of 2 or less are at depths of 8 to 18 inches. Texture is silt loam or silty clay loam. Structure ranges from moderate to strong, fine to medium subangular blocky, blocky or prismatic.
The Bx horizon has hue of 10YR or 7.5YR, value of 5 or 6, and chroma of 4 through 8 and normally has many grayish and brown mottles. Texture is silt loam or silty clay loam in the fine-earth fraction and has medium or coarse angular or subangular blocky arranged in very coarse prisms to medium or thick platy structure. Fragipan expression is weak or moderate. Some pedons have friable to firm silt loam to silty clay BC horizons below the fragipan.
The C horizon has hue of 10YR through 5YR, value of 2 through 6, and chroma of 2 through 8. Texture ranges from loam to clay in the fine-earth fraction. Some pedons have 2C horizons containing high amounts of shale.
COMPETING SERIES: The Lawrence series is the only member of this family. The soils formed in a silty mantle of loess or alluvium, colluvium, and the underlying residuum of limestone on nearly level stream terraces, alluvial fans, and on nearly level concave uplands
The Chalfont, Haubstadt, Pekin, Robbs, Rohrersville, Rossmoyne, Sciotoville, and Shakamak series are in closely related families. Chalfont soils have a lithologic discontinuity with a distinct increase in rock fragments within the series control section. Haubstadt and Shakamak soils have sola more than 60 inches thick. Pekin, Rossmoyne, and Sciotoville soils have strongly to very strongly acid Bt horizons. Robbs soils are formed from loess. Rohrersville soils have hues of 2.5Y or 5Y in the B horizon.
GEOGRAPHIC SETTING: Penlaw soils are on nearly level to sloping concave areas with slope gradients of 0 to 15 percent. Penlaw soils formed in colluvium derived largely from limestones but with some admixture of shale and sandstone. The climate is temperate and humid. Mean annual precipitation ranges from 35 to 50 inches, the mean annual temperature ranges from 50 to 58 degrees F., and the frost-free season ranges from 140 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Clarksburg, Duffield, Edom, Frankstown, Frederick, Hagerstown, Hublersburg, Millheim, Ryder, Thorndale and Washington series. Clarksburg soils lack low chroma redoximorphic feature within 18 inches of the surface. Thorndale are very deep, poorly drained soils formed in medium textured colluvium derived from limestone, calcareous shale, and siltstone. Soils of all the other series listed lack fragipans.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained. Surface runoff is low to medium and saturated hydraulic conductivity is moderately low to moderately high.
USE AND VEGETATION: About 90 percent is cleared and used for general crops or pasture. Wooded areas are in mixed hardwoods of oak and hickory.
DISTRIBUTION AND EXTENT: Pennsylvania and Maryland. The series is of moderate extent. Pennsylvania has about 15,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Franklin County, Pennsylvania, 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon - the zone from the surface of the soil to a depth of about 10 inches (Ap horizon).
2. Argillic horizon - the zone from about 10 inches to a depth of about 23 inches (Bt horizon).
3. Fragipan - The zone from 23 inches to a depth of about 50 inches (Bx1 and Bx2 horizons).
2008 Pedon description and competing series updated