LOCATION UNICOI TN+NCEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, semiactive, mesic Lithic Dystrudepts
TYPICAL PEDON: Unicoi very cobbly sandy loam--forested.(Colors are for moist soil unless otherwise stated.)
Oe-0 to 1 inch; moderately decomposed pine needles and hardwood leaves.
Oa-1 to 2 inches; highly decomposed litter in a fibrous root mat.
A-2 to 3 inches; very dark grayish brown (10YR 3/2) very cobbly sandy loam; weak fine granular structure; very friable; many fine and medium, few coarse roots; 40 percent by volume cobbles and pebbles; strongly acid; abrupt wavy boundary. (1 to 6 inches thick)
BA-3 to 7 inches; brown (10YR 5/3) very cobbly sandy loam; weak fine and medium granular structure; very friable; many fine and medium, few coarse roots; 40 percent by volume cobbles and pebbles; strongly acid; clear wavy boundary. (0 to 5 inches thick)
Bw-7 to 17 inches; yellowish brown (10YR 5/6) very cobbly sandy loam; weak fine subangular blocky structure; very friable; common fine, medium, and coarse roots; 50 percent by volume cobbles and pebbles; strongly acid. (5 to 12 inches thick)
R-17 to 25 inches; hard metasandstone bedrock.
TYPE LOCATION: Johnson County, Tennessee; 800 feet south 40 degrees east from McQueen Knob Lookout; Shady Valley TN-NC USGS Topographic Quadrangle; Latitude: 36 degrees, 34 minutes, 11 seconds north; Longitude: 81 degrees; 55 minutes, 17 seconds west.
RANGE IN CHARACTERISTICS: The thickness of the solum ranges from about 7 to 20 inches, and commonly is the same as the depth to bedrock.Amount of rock fragments in the soil averages between 35 and 60 percent by volume.Some surface layers may have 15 to 35 percent rock fragments. The soil is strongly acid to extremely acid. Content of flakes of mica is none or few throughout. .
The A horizon has hue of 10YR or 2.5Y, value of 3 to 6 and chroma of 1 to 4. The A horizon is loam, fine sandy loam, or sandy loam in the fine-earth fraction.
The AB horizon, where present, has hue of 10YR, or 2.5Y, value of 4 or 5, and chroma of 3 or4. Textures in the fine-earth fraction are the same as for the A horizon.
The Bw horizon has hue of 7.5YR to 2.5Y, value of 4 to 6, and chroma of 3 to 8, or it is mottled in shades of brown and yellow. The Bw horizon is loam, fine sandy loam, or sandy loam in the fine-earth fraction.
In some pedons there is a C horizon, 3 to 6 inches thick, that has colors and textures similar to theBw horizon.
The R horizon is hard bedrock of metasedimentary rock such as arkose, metagraywacke, metasandstone, or quartzite. The upper boundary is considered as lithic contact where root spacing is greater than 4 inches.
COMPETING SERIES: These are the Bugley and Rohan soils in the same family and the Arnot, Grouslous, Klinesville, Nassau Sylvatus, Weikert, and Zango soils in related families. Bugley soils contain fragments of sericite schist or graphitic schist throughout the solum. Rohan soils contain fragments of black fissile, carbonaceous shale throughout the solum. Arnot and Nassau soils contain fragments of sandstone or shale from glacial till. Grouslous soils have more than 27 percent clay in the particle-size control section. Klinesville soils have hues of 5YR or redder throughout the solum. Sylvatus soils contain fragments of finer-grained metasedimentary rocks such as phyllite or slate throughout the solum. Weikert soils contain fragments of shale and siltstone throughout the solum. Zango soils formed in colluvium and have mixed rock fragments of tuff, breccia and andesite.
GEOGRAPHIC SETTING: Unicoi soils are mainly on ridges and side slopes of intermediate mountain ridges at elevations of 1,800 to 4,800 feet. These soils have about 7 to 95 percent slopes. These soils formed in residuum that is affected by soil creep in the upper part and are weathered from metasedimentary rock such as arkose, metagraywacke, metasandstone, or quartzite. Rock outcrops are common in most areas. Mean annual temperature is 50 to 60 degrees F. and mean annual precipitation is about 45 to 50 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brookshire, Chestoa, Ditney Harmiller, Jeffrey, Keener, Lostcove, Marbleyard, Maymead, McCamy, Northcove, Shinbone, Soco, Spivey, Stecoah, and Whiteoak series. Brookshire, Keener, Lostcove, Maymead, Northcove, Spivey, and Whiteoak soils formed in colluvium and are on foot slopes and toe slopes. Chestoa, Ditney, Harmiller, Jeffrey, Marbleyard, McCamy, Shinbone, Soco, and Stecoah soils are on ridgetops and side slopes. All of these soils are deeper than 20 inches to lithic or paralithic contact.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; moderately rapid permeability; moderately high or high saturated hydraulic conductivity. Index surface runoff class is low or medium on strong sloping to moderately steep slopes and medium or high on steep and very steep slopes.
USE AND VEGETATION: Common trees are pitch pine, table mountain pine, Virginia pine, scarlet oak, hemlock, and chestnut oak.
DISTRIBUTION AND EXTENT: The Blue Ridge (MLRA 130) in Tennessee, North Carolina, Virginia, and possibly in Georgia. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Lexington, Kentucky
SERIES ESTABLISHED: Monroe County, Tennessee; 1974.
REMARKS: Unicoi soils formerly were included in the Ramsey series and classified in Lithosols great soil group. The 12/97 revision placed Unicoi soils in a semiactive CEC activity class. The 3/99 revision updated the classification to 8th Edition to Keys to Soil Taxonomy (1998) standards and expanded the lower slope range from 8 to 7 percent to facilitate the correlation of Grayson County, Virginia. Fine sandy loam texture was added to the RIC for the Bw and C horizons. The 6/00 revision reflects the movement of the official type location from Monroe County, TN to Johnson County, TN.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface of the soil to 7 inches (Oe, Oa, A1, and BA horizons)
Cambic horizon - the zone from 7 to 17 inches (Bw horizon)
Lithic contact - the occurrence of hard bedrock at 17 inches (R horizon)
SIR = TN0054; TN0148, Variant
Revised: 12/97-RLL,RRD; 3/99-DHK; 6/99, 10/01-MKC