LOCATION SEQUOIA TN+KY NC VAEstablished Series
TAXONOMIC CLASS: Fine, mixed, semiactive, mesic Typic Hapludults
TYPICAL PEDON: Sequoia silt loam--cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) silt loam; moderate medium granular structure; friable; medium acid; clear smooth boundary. (4 to 9 inches thick)
Bt1--6 to 9 inches; strong brown (7.5YR 5/6) silty clay loam; moderate medium subangular blocky structure; firm; few distinct clay films on faces of peds; medium acid; clear smooth boundary.
Bt2--9 to 24 inches; yellowish red (5YR 5/8) silty clay; few fine prominent strong brown (7.5YR 5/6) and pale brown (10YR 6/3) mottles; strong medium angular blocky structure; very firm; common prominent clay films on faces of peds; few fine dark concretions; strongly acid; gradual smooth boundary.
Bt3--24 to 32 inches; yellowish red (5YR 5/8) silty clay; common medium prominent yellow (10YR 7/8) and pale brown (10YR 6/3), and common medium distinct red (2.5YR 4/8) mottles; strong medium angular blocky structure; very firm; common prominent clay films on faces of peds; strongly acid; clear wavy boundary. (Thickness of the Bt horizon ranges from 15 to 35 inches.)
BC--32 to 36 inches; strong brown (7.5YR 5/8) silty clay; many fine and coarse distinct brownish yellow (10YR 6/8) and common fine prominent red (2.5YR 4/8) and light gray (10YR 7/2) mottles; weak medium platy structure; very firm; few fine dark concretions; about 15 percent soft fragments of shale; strongly acid; clear wavy boundary. (0 to 14 inches thick)
Cr--36 to 70 inches; soft shale with thin seams of silt loam coating rock strata and extending into cracks.
R--70 inches; hard shale bedrock.
TYPE LOCATION: Blount County, Tennessee; 850 feet north of Clover Hill and 1,200 feet west of Hopewell Church.
RANGE IN CHARACTERISTICS: Thickness of solum and depth to rippable bedrock ranges from 20 to 40 inches. Reaction is strongly acid or very strongly acid except where lime has been added. Coarse fragments of shale range from 0 to 10 percent in the A horizon and from 0 to 25 percent in the B and C horizons.
The A or Ap horizon has hue of 10YR, value of 3 to 5, and chroma of 2 to 4. Horizons with value of 3 are less than 6 inches thick. Severely eroded pedons have hue of 7.5YR or 5YR, value of 4 or 5, and chroma of 4 to 8. Texture is silt loam or rarely loam. Severely eroded areas are silty clay loam, silty clay, or rarely clay loam.
The upper part of the Bt horizon has hue of 10YR, 7.5YR, or 5YR, value of 4 or 5, and chroma of 4 to 8, and the lower part has hue of 7.5YR, 5YR, or 2.5YR, value of 4 or 5, and chroma of 4 to 8. Some pedons are mottled with shades of brown, yellow, or red. Texture of the fine earth is silty clay, clay, or silty clay loam.
The BC horizon or C horizon, where present, has hue of 10YR, 7.5YR, or 5YR, value of 4 or 5, and chroma of 6 or 8. Some pedons are an evenly mottled pattern in shades of brown, yellow, red, and gray. Texture of the fine earth is silty clay, clay or silty clay loam.
The Cr horizon is soft shale with thin seams of silt loam or silty clay loam between rock strata.
COMPETING SERIES: These are the Agnos, Boden, Braddock, Buckhall, Christian, Clifton, Fairfax, Grassville, Groseclose, Howell, Lodi, Monmouth, Muse, Pervina, Quantico, Timberville, Trappist and Unison series in the same family. All of these series except Trappist are deeper than 40 inches to bedrock. Trappist soils formed in colluvium or residuum from black fissile shale and siltstone. The Bt horizon in Trappist has dominant hue of 7.5YR or 10YR.
The Enders series is in a similar family. Enders soils are deeper than 40 inches to bedrock and are thermic.
GEOGRAPHIC SETTING: Sequoia soils are on gently rolling to steep upland ridges. Slopes range from 3 to 35 percent. The soil formed in residuum of acid shale and siltstone. Near the type location, the average annual temperature is 58 degrees F., and average annual rainfall is 47 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Muse series and the Gilpin, Leadvale, Litz and Shelocta series. Gilpin and Shelocta soils are fine-loamy. Leadvale soils are on foot slopes and benches and have a fragipan. Litz soils are on similar positions and are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Sequoia soils are well drained. Runoff is medium to rapid and permeability is moderately slow.
USE AND VEGETATION: Most of the cleared areas are used for growing pasture and hay. A few small areas are used for growing tobacco, small grains, and corn. The native vegetation was mixed hardwoods.
DISTRIBUTION AND EXTENT: The Appalachian Ridges and Valleys and Cumberland Plateau and Mountains regions in Tennessee, Kentucky and Virginia. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Hamblen County, Tennessee; 1940
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 6 inches (Ap horizon)
Argillic horizon - 6 to 32 inches (Bt horizons)
Paralithic contact - 36 inches (top of Cr horizon)