LOCATION MILLROCK VAEstablished Series
TAXONOMIC CLASS: Mixed, mesic Lamellic Udipsamments
TYPICAL PEDON: Millrock loamy sand - cropland (Colors are for moist soil)
Ap--0 to 15 centimeters; dark brown (7.5YR3/2) loamy sand; single grained; loose; many fine and few medium roots;
slightly acid; abrupt smooth boundary. (0 to 25 centimeters thick)
B--15 to 35 centimeters; brown (7.5YR4/4) loamy sand; single grained; very friable; many fine and few medium roots; slightly acid; abrupt smooth boundary. (25 to 50 centimeters thick)
Ab--35 to 65 centimeters; dark brown (7.5YR3/2) loamy sand; single grained; very friable; few fine and medium roots; irregular strata of brown (7.5YR4/4) loamy sand; slightly acid; abrupt smooth boundary. (15 to 45 centimeters thick)
Eb--65 to 100 centimeters; brown (7.5YR4/4) loamy sand; single grained; very friable; few fine and medium roots; slightly acid; clear wavy boundary. (10 to 45 centimeters thick)
Eb and Btb--100 to 150 centimeters; brown (7.5YR4/4) loamy sand with about 15 percent of the volume thin reddish brown (5YR4/3) fine sandy loam lamellae (Btb part). The Eb matrix is single grained; very friable. The lamellae have weak fine subangular blocky structure; very friable; thin clay bridging between sand grains is evident; slightly acid.
TYPE LOCATION: Rockingham County, Virginia 2.7 kilometers southeast of Mount Crawford, 10 meters north of North River and 30.3 meters west of C & W Railroad Bridge.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 75 to more than 150 centimeters. Depth to bedrock is more than 2 meters. The content of pebbles mainly sandstone, ranges from 0 to 10 percent above 15 centimeters, and from 0 to 20 percent at depths of 15 to 100 centimeters. Below 100 centimeters pebble content ranges from 0 to 40 percent, and cobblestone content ranges from 0 to 15 percent. The soil is slightly acid or neutral. Combined thickness of lamellae in the upper 150 centimeters is less than 15 centimeters.
The A horizons have hues of 7.5YR or 10YR, values of 3 or 4, and chromas of 2 through 4. They are loamy sand, loamy fine sand, sandy loam, or fine sandy loam.
The B horizons have hues of 5YR through 10YR, values of 3 or 4, and chromas of 2 through 4. They are loamy sand, loamy fine sand or their gravelly analogues except lamellae also include fine sandy loam.
Some pedons have C and (C and Bt) horizons. They have hues of 10YR to 5YR, values of 3 to 5 and chromas of 3 or 4. They are loamy sand, sand or their gravelly analogues. Lamellae of fine sandy loam, 2 to 5 centimeters thick, amount to as much as 20 percent of the matrix below 120 centimeters in some places.
COMPETING SERIES: These are the Chelsea, Coloma, Colonie, and Lakin, in the same family. Chelsea, Coloma, Colonie, and Lakin soils do not have buried A horizons.
GEOGRAPHIC SETTING: The Millrock soils are on nearly level to gently sloping soils on natural levees adjacent to larger streams and rivers in the limestone valleys. Slope gradients range from 0 to 7 percent commonly being less than 4 percent. The soil formed in alluvial sediments derived from residuum of sandstone, shale, and limestone. The mean annual air temperature near the type location is about 9 degrees C. Annual precipitation averages about 92 centimeters. Elevation ranges from 230 to 410 kilometers.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buckton, Chagrin, Chavies, Craigsville, and Tioga series. The Buckton soils have a fine-silty particle size control section and contain free carbonates throughout the solum. Chagrin soils have a fine-loamy particle-size control section and contain free carbonates throughout the solum. The Chavies and Tioga soils have a coarse-loamy particle-size control section. The Craigsville soils have a loamy-skeletal particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; rapid permeability.
USE AND VEGETATION: Most are cultivated and used for growing corn, hay, or pasture. The remainder is in woodland. Native
vegetation was mixed hardwoods.
DISTRIBUTION AND EXTENT: Virginia and possibly West Virginia and Tennessee. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Rockingham County, Virginia 1977.
REMARKS: Virginia Polytechnic Institute and State University data for the type location shows mixed mineralogy, but borderline to siliceous. Additional data is not yet available. Hach kit analysis and pH suggest placement as Alfic Udipsamments.
The 12/2005 revision updates this soil to the 9th Edition of the Keys to Soil Taxonomy (2003). In addition, the horizon nomenclature in the typical pedon description and the range in characteristics was revised.
Competing series and other sections on the OSD were not revised.
Previous revision dates: 7/81--RLG