LOCATION BEARKNOB VA
Established Series
JDH, JRT/Rev. JRT
07/2013
BEARKNOB SERIES
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Humic Fragiaquepts
TYPICAL PEDON: Bearknob peat on a 2 percent slope at 4713 feet elevation in rangeland/pasture. (Colors are for moist soil)
Oi--0 to 20 cm; dark yellowish brown (10YR 3/4) peat. (0 to 38 cm (6 to 15 inches thick))
Oe--20 to 36 cm; dark brown (10YR 3/3) mucky peat. (0 to 38 cm (6 to 15 inches thick))
A--36 to 41 cm; very dark brown (10YR 2/2) very gravelly mucky sandy loam; weak medium granular structure; friable; many very fine, fine, and medium roots; 35 percent gravel, cobbles, and stones; extremely acid; clear wavy boundary. (0 to 15 cm thick (0 to 6 inches)
Bgx1--41 to 64 cm; light brownish gray (10YR 6/2) very gravelly loamy sand; moderate very thick platy structure; firm, brittle; 40 percent gravel, cobbles, and stones; very strongly acid; abrupt wavy boundary.
Bgx2--64 to 76; light brownish gray (10YR 6/2) very gravelly loamy sand; moderate very thick platy structure; firm, brittle; 40 percent gravel, cobbles, and stones; common medium prominent strong brown (7.5YR 5/6) masses of oxidized iron; very strongly acid; clear wavy boundary. (combined thickness of the Bxg horizons is 30 to 75 cm (12 to 30 inches))
Cdg1--76 to 91 cm; light brownish gray (10YR 6/2) very gravelly loamy sand; massive; very firm, brittle; 40 percent gravel; few medium prominent dark yellowish brown (10YR 4/6) masses of oxidized iron; very strongly acid; clear wavy boundary.
Cdg2--91 to 158 cm; gray (2.5Y 6/1) gravelly sandy loam; massive; very firm, brittle; 25 percent gravel; very strongly acid.
TYPE LOCATION:
State: Virginia
County: Grayson
USGS Topographic Quadrangle: Trout Dale, VA
Latitude: 36.658889 N NAD 27
Longitude: 81.483889 W NAD 27
Directions to pedon: (Jefferson National Forest, Mt. Rogers National Recreation Area); about 19,800 feet southwest 220 degrees of the intersection of Highways VA-16 and VA-603, 4,000 feet south southeast 165 degrees of the gate at the "Scales".
RANGE IN CHARACTERISTICS:
Depth to the top of the fragipan: 30 to 75 cm (12 to 30 inches)
Rock Fragment Content: has 0 to 55 percent by volume gravel, cobbles, and stones in the O horizon; 5 to 55 percent by volume gravel, cobbles and stones in the A and B horizons 5 to 55 percent gravel in the C horizon.
The particle-size control section averages more than 35 percent rock fragments.
Solum Thickness: 50 to 100 cm
Depth to Bedrock: Greater than 152 cm
Depth Class: Very Deep
Soil Reaction: Extremely acid to strongly acid.
Range of Individual Horizons:
O horizon:
Color--hue of 10YR, value or 2 or 3, and chroma of 1 to 4.
Texture: Fibric, hemic, or sapric material.
A horizon:
Color--hue of 10YR, value of 2 or 3, and chroma of 1 or 2; or is neutral with value of 2 or 3 . Texture is loamy sand, sandy loam, fine sandy loam, loam, or silt loam in the fine-earth fraction. Mucky analogues are present in most pedons.
B horizon:
Color--hues of 10YR to 5Y, value of 4 to 6, and chroma of 1 or 2; or is neutral with value of 4 or 6. Texture is loamy sand, sandy loam, fine sandy loam, loam, or silt loam in the fine-earth fraction. Consistence is firm to extremely firm and brittle.
C horizon:
Color--hues of 10YR to 5Y, value of 4 to 6, and chroma of 1 or 2; or is neutral with value of 4 or 6. Texture:--loamy sand, sandy loam, fine sandy loam, loam, or silt loam in the fine-earth fraction. Consistence is firm to extremely firm and brittle.
COMPETING SERIES:
There are no known series in the same family.
GEOGRAPHIC SETTING:
MLRA(s) using this series: 130B Southern Blue Ridge
Landscape: Mountain range
Landform: Mountain valleys, drainageways, and depressions
Geomorphic Component: Base slope
Hillslope Profile Position: Footslopes and toeslopes
Parent Material Origin: Rhyolite or granite
Parent Material Kind: Loamy colluvium
Slope: 0 to 15 percent
Elevation: Above 1219
Frost-free period: 75 to 130 days
Mean Annual Air Temperature: 4 to 8 degrees C (40 to 47 degrees F).
Mean Annual Precipitation: 1140 to 1520 millimeters
Moist atmospheric conditions are prevalent and fog and cloud inundation is common in these high mountain areas.
GEOGRAPHICALLY ASSOCIATED SOILS:
Balsam soils do not have dense soil material or a fragipan and are well drained.
Bloodyhorse soils do not have dense soil material or a fragipan and are well drained.
Buzzrock soils do not have dense soil material or a fragipan and are well drained.
Mt Rogers soils do not have dense soil material or a fragipan and are well drained.
Nopan soils are coarse-loamy in the particle-size control section, do not have a histic epipedon, dense soil material, or a fragipan.
Scales soils are loamy in the particle-size control section.
Snowsnake soils are moderately well drained.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage Class (Agricultural): Poorly Drained
Internal Free Water Occurrence: Yes
Index Surface Runoff: moderate to high
Saturated Hydraulic Conductivity Class: low to moderately low
Permeability Class (obsolete): slow to very slow
Shrink-swell Potential: none
Flooding Frequency and Duration: none
Ponding Frequency and Duration: none to frequent and brief to long in duration.
USE AND VEGETATION:
Major Uses: Nearly all areas are in rangeland/pasture. A few areas are in forest land
Vegetation: Alder, blueberry, hemlock, gray birch, spruce, and fir
DISTRIBUTION AND EXTENT:
Distribution: Virginia
Extent: The series is of small extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: MORGANTOWN, WEST VIRGINIA
SERIES ESTABLISHED: Jefferson National Forest, in Grayson County, Virginia, 2013.
REMARKS: 07/2013 revision updates Series Established section.
ADDITIONAL DATA: Characterization data is available from the NSSL for the following pedons:
Laboratory data are available for the type location from Virginia Polytechnic Institute and State University.
NASIS Site ID: 281515
NASIS Pedon ID: 280774
NASIS User Pedon ID: Bearknob OSD
NASIS DATA MAPUNIT ID = 540229 (Standard Component Data)
National Cooperative Soil Survey
U.S.A.