LOCATION BROCKROAD VAEstablished Series
TAXONOMIC CLASS: Fine, mixed, semiactive, thermic Typic Hapludults
TYPICAL PEDON: Brockroad silt loam-on a convex slope of 4 percent under mixed hardwood and pine forest. (Colors are for moist soil.)
01--5 to 0 cm; partly decomposed hardwood leaves, pine needles, and twigs.
A1--0 to 3 cm; dark grayish brown (10YR 4/2) silt loam; moderate very fine granular structure; very friable; many fine and medium roots; 2 percent rounded and subrounded reddish quartz pebbles; very strongly acid; abrupt smooth boundary. (0 to 10 cm thick)
A2--3 to 23 cm; pale brown (10YR 6/3) silt loam; moderate very fine granular structure; very friable; many fine and medium roots; 2 percent rounded reddish quartz pebbles; very strongly acid; clear smooth boundary. (0 to 30 cm thick)
B1t--23 to 38 cm; light yellowish brown (10YR 6/4) silty clay loam; weak fine subangular blocky structure; friable, slightly sticky, slightly plastic; many fine and medium roots; few thin clay films on faces of peds; 2 percent rounded reddish quartz pebbles; very strongly acid; clear smooth boundary. (0 to 20 cm thick)
B21t--38 to 79 cm; yellowish brown (10YR 5/8) clay; moderate fine and medium subangular blocky structure; firm, sticky, plastic; common fine and medium roots; common medium and thin clay films on faces of peds; 2 percent rounded reddish quartz pebbles; strongly acid; clear smooth boundary.
B22t--79 to 109 cm; yellowish red (5YR 5/6) clay; common medium distinct light yellowish brown (10YR 6/4) mottles; moderate fine and medium subangular blocky structure; firm, plastic, sticky; few fine roots; common medium and thin clay films on faces of peds; 2 percent rounded reddish quartz pebbles; strongly acid; clear
smooth boundary.
IIB23t--109 to 150 cm; yellowish red (5YR 5/6) clay; many medium and coarse distinct yellowish brown (10YR 5/4) mottles; weak medium subangular blocky structure; firm, slightly sticky, slightly plastic; few fine roots; common medium clay films on faces of peds; common very fine flakes of mica; strongly acid; gradual smooth boundary. (Combined thickness of the B2t horizon is 60 to 130 cm.)
IIB3t--150 to 190 cm; yellowish red (5YR 5/6) silty clay loam; common coarse faint red (2.5YR 5/6) and reddish yellow (7.5YR 6/6) mottles; weak fine subangular blocky structure; friable, slightly plastic; few thin and medium clay films on faces of peds; many fine flakes of mica; strongly acid; gradual smooth boundary. (15 to 60 cm thick)
IICr--190 to 264 cm; multicolored yellowish red (5YR 5/6) strong brown (7.5YR 5/6) and white (10YR 8/2) silt loam; massive; highly weathered schist; many very fine flakes of mica; strongly acid.
TYPE LOCATION: Spotsylvania County, Virginia; about 16 kilometers northwest of Spotsylvania, about 4 kilometers west of the junction of Route 613 and 621 and about 14 meters north of Route 621.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 125 to 200 cm or more. Depth to lithologic discontinuity ranges from 60 to 125 cm. Depth to hard bedrock is greater than 180 cm. Content of coarse fragments ranges from 1 to 15 percent in horizons from the surface to the lithologic discontinuity. These consist of rounded and subrounded reddish quartz pebbles. Coarse fragments below the lighologic discontinuity consist mostly of weathered schist fragments and angular vein quartz. These commonly increase in quantity in the lower part of the profile and range up to 35 percent in the IIB3 and IIC horizons. Silt content is more than 30 percent in the particle-size control section. The sand fraction is dominantly quartz in the horizons above the lithologic discontinuity and dominantly mica in the lower part of the solum. Mica content is very low in the upper part of the solum and common to many in the lower part. A thin or discontinuous stone line is present at the lithologic discontinuity in some pedons. The soil is strongly or very strongly acid unless limed.
The A horizon has hue of 7.5YR through 2.5Y, value of 3 through 6, and chroma of 2 through 6. Value of 3 or less isrestricted to the A1 or Ap horizon. It is silt loam, loam, or fine sandy loam. The B1 horizon, where present, and the B2t horizon above the lithologic discontinuity have hue of 5YR through 10YR, value of 4 or 5 and chroma of 4 through 8. The IIB2t horizon has hue of 2.5Y through 7.5YR, value of 4 through 6 and chroma of 4 through 8 and commonly has mottles of high value and chroma.
The B2t and IIB2t horizons are clay, silty clay, clay loam or silty clay loam with clay content ranging from 35 to 70 percent. The IIB3t horizon commonly is mottled in shades of red, brown or yellow. It is clay, silty clay loam, clay loam, loam or silt loam.
The C horizon commonly is multicolored. It is clay loam, silt loam or loam or strongly weathered mica schist bedrock which crushes easily to silt loam or loam.
COMPETING SERIES: These are the Albertville, Carnasaw, Catharpin, Cullen, Cunningham, Cuthbert, Enders, Endsaw, Fluvanna, Galilee, Gritney, Kirvin, Luverne, Masada, McQueen, Nason, Remlap, Sweatman, Tatum, Townley, Vance and Williamsville series. All of these soils, with the exception of Catharpin and Masada soils, lack a lithologic discontinuity above which are reddish quartz pebbles. Albertville soils are 100 to 150 cm to shale bedrock. Carnasaw, Enders and Sweatman soils have coarse fragments dominanted by shale, siltstone or sandstone. Catharpin, Cullen and Tatum soils have hues of 10R or 2.5YR throughout the B2t horizon. Cunningham, Cuthbert, Galilee, Townley and Vance soils have sola less than 100 cm thick. Endsaw and Gritney soils have gray mottles in the lower part of the B horizon. Fluvanna soils do not commonly contain mica flakes. Gritney, Luverne, Masada and Vance soils have less than 30 percent silt in the particle-size control section. Kirvin soils have coarse fragments dominated by ironstone pebbles. McQueen soils either lack coarse fragments or have coarse fragments dominanted by quartz or chert. Nason soils have a solum 60 to 125 cm thick and coarse fragments dominanted by quartz and schist. Williamsville soils are sandy clay loam, loam or sandy loam in the lower part of the B2 horizon. The Appling and Herndon series are similar soils in a related family. They have kaolinitic mineralogy.
GEOGRAPHIC SETTING: The Brockroad soils are on slightly convex upland ridges and sideslopes. Slope gradients are commonly 2 to 7 percent with a range of 0 to 15 percent. These soils formed in a mantle of silty and clayey sediments containing reddish quartz pebbles, and underlying clayey materials weathered from mica schist and gneiss. Mean annual air temperature is above 15 degrees C and the mean annual precipitation is about 107 cm.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Catharpin, Nason, and Tatum soils and the Fluvanna, Georgeville and Lignum soils. Fluvanna and Georgeville soils lack a lithologic discontinuity. Lignum soils have low chroma mottles in the Bt horizons.
DRAINAGE AND PERMEABILITY: Well drained. Runoff and internal drainage is medium. Permeability is moderate.
USE AND VEGETATION: Most of these soils are in mixed hardwood and pine forest. The remainder is cropland or pasture.
DISTRIBUTION AND EXTENT: Virginia; possibly North Carolina and South Carolina. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: Campbell County, Virginia, 1973.
TABULAR SERIES DATA:
SOI-5 Soil Name Slope Airtemp FrFr/Seas Precip Elevation VA0075 BROCKROAD 0- 15 59- 64 185-220 35- 45 250- 800SOI-5 FloodL FloodH Watertable Kind Months Bedrock Hardness VA0075 NONE 6.0-6.0 - 60-60
SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC- VA0075 0- 9 SIL L FSL 0- 0 75- 95 10-27 - VA0075 9-59 C SIC SICL 0- 5 75- 95 35-70 - VA0075 59-75 SIL L C 0- 10 55- 75 20-55 - VA0075 75-80 WB - - - -
SOI-5 Depth -pH- O.M. Salin Permeab Shnk-Swll VA0075 0- 9 4.5- 5.5 1.-3. 0- 0 0.6- 6.0 LOW VA0075 9-59 4.5- 5.5 0.-.5 0- 0 0.6- 2.0 MODERATE VA0075 59-75 4.5- 5.5 0.-.5 0- 0 0.6- 2.0 MODERATE VA0075 75-80 - - - 0.00-0.06