LOCATION BLACKARN VA
Established Series
MHC, TWB, JRT/Rev. JRT
07/2013
BLACKARN SERIES
TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Pachic Humudepts
TYPICAL PEDON: Blackarn cobbly loam on a 58 percent northwest facing upper back slope at 4940 feet elevation--Forested. (Colors are for moist soil unless otherwise stated.)
A1--0 to 9 cm; black (5YR 2.5/1) cobbly loam; very dark brown (10YR 2/2) dry; weak fine granular structure; very friable; many fine to coarse roots; 15 percent rock fragments, mainly cobbles and gravel; extremely acid; clear wavy boundary.
A2--9 to 33 cm; dark brown (7.5YR 3/2) very cobbly loam; weak medium granular structure; very friable; common fine to coarse roots; 45 percent rock fragments, mainly cobbles; extremely acid; clear wavy boundary.
A3--33 to 76 cm; very dark gray (10YR 3/1) very cobbly sandy loam; weak medium granular structure; very friable; common fine to coarse roots; 50 percent rock fragments, mainly cobbles; extremely acid; clear wavy boundary. (combined thickness of A horizon is 20 or more inches)
Bw--76 to 158 cm; brown (7.5YR 4/4) extremely cobbly sandy loam; weak coarse subangular blocky structure; very friable; common fine to coarse roots; 70 percent rock fragments, mainly cobbles; very strongly acid.
TYPE LOCATION:
State: Virginia
County: Smyth
USGS Topographic Quadrangle: Whitetop Mountain
Latitude: 36.668056 N NAD 83.
Longitude: 81.547222 W NAD 83.
Direction to the pedon: Jefferson National Forest, Mt Rogers National Recreation Area about 19,000 feet east 95 degrees of the intersection of Highways VA600 and VA603; 7350 feet south southwest of the intersection of Highways VA603 and NF828, in a mixed woodland.
RANGE IN CHARACTERISTICS:
Solum thickness ranges from 40 to 72 inches or more. Depth to bedrock is more than 60 inches. Reaction ranges from extremely acid to strongly acid. Rock fragment content ranges from 15 to 90 percent by volume. Average rock fragment content in the particle-size control section ranges from 35 to 90 percent by volume. They range from gravel to boulders in size. Typically, the amount of rock fragments increases with depth. Rock fragment content is typically more than 50 percent in the C horizon.
Range of Individual Horizons:
The A horizon has hue of 5YR to 2.5Y, value of 2 or 3, and chroma of 1 to 3. Texture is silt loam, fine sandy loam, sandy loam, or loam in the fine-earth fraction.
A thin AB horizon occurs in some pedons. It has hue of 7.5YR to 2.5Y, value of 3 to 6 and chroma of 4 to 8. Texture is silt loam, fine sandy loam, sandy loam, or loam in the fine-earth fraction.
The Bw horizion has hue of 7.5YR to 2.5Y, value of 4 to 6, and chroma of 3 to 8. Texture is silt loam, fine sandy loam, sandy loam, or loam in the fine-earth fraction.
The C horizon, where present, has hue of 7.5YR to 2.5Y, value of 4 to 6, and chroma of 4 to 8. Texture is silt loam, loam, fine sandy loam, sandy loam, coarse sandy loam, loamy sand, loamy fine sand, or loamy coarse sand in the fine-earth fraction.
COMPETING SERIES:
Tolfork series formed in metasedimentary or metavolcanic rock types in mountainous areas of southwestern Oregon and are 40 to 60 inches deep to bedrock.
GEOGRAPHIC SETTING:
MLRA(s) using this series: 130B
Landscape: Mountain system
Landform: Mountain slope
Geomorphic Component: Mountain top
Hillslope Profile Position: Mountain flank
Parent Material Origin: Felsic, intermediate, and mafic high-grade metamorphic or igneous rocks such as mica gneiss, granite, rhyolite, hornblende gneiss, and hornblende schist
Parent Material Kind: Colluvium
Slope: 2 to 80 percent
Elevation: 1219 to above 1341 meters
Frost-free period: 75 to 130 days
Mean Annual Air Temperature: 40 to 47 degrees F.
Mean Annual Precipitation: 1140 to 1520 millimeters
These soils are found mainly on north or cool aspects, but are not limited to these positions. Moist atmospheric conditions are prevalent and fog and cloud inundation is common in these high mountain areas.
GEOGRAPHICALLY ASSOCIATED SOILS:
Bloodyhorse soils have bedrock within 20 to 40 inches.
Buzzrock soils have bedrock within 40 to 60 inches.
Craggey soils are in the loamy family and have bedrock within 20 inches.
Mt Rogers soils have a dark surface between 10 and 19 inches thick.
Tanasee soils have a dark surface between 10 and 19 inches thick and are coarse-loamy.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage Class (Agricultural): Well Drained
Internal Free Water Occurrence:
Index Surface Runoff: Very low runoff where forest litter has not been disturbed or only partially removed; medium to very high runoff where litter has been removed.
Saturated Hydraulic Conductivity Class: High
Permeability Class (obsolete): Moderately rapid
Shrink-swell Potential: Low
Flooding Frequency and Duration: None
Ponding Frequency and Duration: None
USE AND VEGETATION:
Major Uses: Forested
Dominant Vegetation: Red Spruce and Frasier Fir above (5,200'). At lower elevations, northern red oak, yellow birch, black birch, black cherry, sugar maple, eastern hemlock, American beech, and yellow buckeye. Common understory plants are service berry, striped maple, American chestnut sprouts, silver bell, witch hobble, rhododendron, blueberry, and smooth blackberry. Trillium, yellow mandarin, wood sorrel and New York fern are common forbes. The main uses of this soil are for wildlife and recreational activities.
DISTRIBUTION AND EXTENT:
Distribution: Virginia.
Extent: This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: MORGANTOWN, WEST VIRGINIA
SERIES ESTABLISHED: Jefferson National Forest, Smyth County, Virginia, 2013.
REMARKS: 07/2013 Revision updates Series Established Section.
Diagnostic horizons and soil characteristics recognized in this pedon are:
Umbric epipedon - 0 to 30 inches (A1, A2 and A3 horizons)
Cambic horizon - 30 to 62 inches (Bw horizon)
Skeletal property - average content of more than 35 percent by volume rock fragments in the control section
ADDITIONAL DATA:
Laboratory data are available for the type location from Virginia Polytechnic Institute and State University.
NASIS Site ID: 283196
NASIS Pedon ID: 282520
NASIS User Pedon ID: Blackarn OSD
NASIS DATA MAPUNIT ID = 540512 (Standard Component Data)
National Cooperative Soil Survey
U.S.A.