LOCATION BOULDIN TN+KYEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, siliceous, semiactive, mesic Typic Paleudults
TYPICAL PEDON: Bouldin very cobbly fine sandy loam--forested. (Colors are from moist soil.)
A--0 to 6 inches; dark grayish brown (10YR 4/2) very cobbly fine sandy loam; weak medium granular structure; very friable; many fine and medium roots; 45 percent subrounded indurated sandstone fragments (2 to 500 millimeters); strongly acid; clear wavy boundary. (0 to 10 inches thick)
BE--6 to 11 inches; light yellowish brown (10YR 6/4) extremely cobbly fine sandy loam; weak medium subangular blocky structure; friable; many fine and medium roots; 65 percent subrounded indurated sandstone fragments (2 to 500 millimeters); strongly acid; clear smooth boundary. (5 to 15 inches thick)
Bt1--11 to 22 inches; brown (7.5YR 5/4) extremely cobbly loam, many coarse prominent yellowish red (5YR 5/8) and common fine prominent yellow (10YR 7/8) lithomorphic mottles; weak medium subangular blocky structure; friable; common fine roots; few faint clay films on faces of peds and on rock fragments; 65 percent subrounded indurated sandstone fragments (2 to 500 millimeters); strongly acid; clear smooth boundary.
Bt2--22 to 42 inches; red (2.5YR 5/6) very cobbly sandy clay loam, common medium distinct light red (2.5YR 7/8) lithomorphic mottles; moderate medium subangular blocky structure; friable; few fine roots; few faint clay films on faces of peds and on rock fragments; 50 percent subrounded indurated sandstone fragments (2 to 500 millimeters); strongly acid; gradual wavy boundary.
Bt3--42 to 58 inches; red (2.5YR 5/6) very stony clay loam, many coarse distinct yellowish red (5YR 5/6) and common fine prominent reddish yellow (7.5YR 7/8) lithomorphic mottles; moderate medium angular blocky structure; friable; few fine roots; few faint clay films on faces of peds and on rock fragments; 50 percent subrounded indurated sandstone fragments (2 to 1000 millimeters); very strongly acid; gradual irregular boundary.
Bt4--58 to 83 inches; yellowish red (5YR 5/8) very stony clay, common medium distinct reddish yellow (7.5YR 6/8) and common fine distinct yellowish red (5YR 5/6) lithomorphic mottles; moderate medium angular blocky structure; firm; very few fine roots; few faint clay films on faces of peds and on rock fragments; 55 percent subrounded indurated sandstone fragments (2 to 1000 millimeters); very strongly acid. (Combined thickness greater than 50 inches)
TYPE LOCATION: Grundy County, Tennessee in a logging road-cut along Taylor Creek; about 2 miles (airline) northwest of Beersheba Springs; 35 degrees, 29 minutes, 03 seconds N. Latitude and 85 degrees, 40 minutes, 53 seconds W. Longitude; USGS Altamont Quadrangle NAD83.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 60 to more than 80 inches. Depth to bedrock; limestone, sandstone or shale, ranges from 5 to more than 10 feet. Coarse fragments, mostly consisting of sandstone channers, cobbles, flagstones, or stones, range from 15 to 55 percent in the surface layer and from 35 to 90 percent in the subsoil and substratum. Size of fragments ranges from less than one inch to several feet across, but the dominant range is 10 to 20 inches. Reaction is very strongly or strongly acid throughout.
The A horizon has hue of 10YR, value of 3 or 4, and chroma of 1 to 3. A few small areas have Ap horizons with colors similar to the E horizon. Texture of the fine-earth fraction is fine sandy loam, sandy loam, or loam.
The E horizon, where present, has hue of 10YR, value of 4 to 6, and chroma of 3 or 4. Texture of the fine-earth fraction is fine sandy loam, sandy loam, or loam.
The BE horizon has hue of 5YR to 10YR, value of 4 to 6, and chroma of 4 to 8. Texture of the fine-earth fraction is fine sandy loam, sandy loam, or loam.
The Bt horizon has hue of 2.5YR to 7.5YR, value of 4 to 7, and chroma of 6 or 8. Texture of the fine earth fraction is loam, sandy clay loam, clay loam, or clay.
A BC horizon is present in some pedons with colors and textures similar to the lower Bt. Some are mottled without dominant hue or chroma and the fine-earth texture includes sandy loam.
COMPETING SERIES: These are the Clarksville and Coulstone series in the same family and the Bodine, Grimsley, and Oriskany series in closely related families. Clarksville, Coulstone, and Bodine soils have fragments that are dominantly chert and smaller in size. Bodine soils are in the thermic temperature regime. Grimsley soils have thinner solums and paralithic contact with soft shale at a depth shallower than 60 inches. Oriskany soils have thinner solums.
GEOGRAPHIC SETTING: Bouldin soils form in Pennsylvanian aged interbedded sandstone, siltstone, and shale that weather to form a mantle of stony colluvium that moves down hillslopes and mountainflanks. The colluvial mantle is generally 4 to 10 feet thick and blankets all rock strata from the base of nearly vertical sandstone cliffs, which forms an upper unit boundary, downslope hundreds of feet to the outer edges of valley floors. Commonly, the loamy mantle is thick enough to cover all strata including sandstone, shale and limestone to such a depth that bedrock has little or no influence on taxonomic classification. Slope gradients are dominantly 30 to 75 percent, but range as low as 10 percent in a few places. Near the type location, mean annual temperature is 55.5 degrees F., and mean annual precipitation is 53.5 inches. (Note: The weather station is roughly 300-400 feet higher than the OSD site.)
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beetree, Gilpin, Grimsley, Jefferson, Lily, Muse, Petros, Ramsey, Sequoia, Shelocta, and Zenith soils. With the exception of Grimsley and Petros, none of these associated soils is in a loamy-skeletal family. Beetree, Petros, Ramsey, and Zenith soils do not have argillic horizons. Beetree, Gilpin, Jefferson, Lily, Shelocta, and Zenith soils are in fine-loamy families. Muse and Sequoia soils are in a fine family. Petros and Ramsey soils are in lithic families and Ramsey soils are in a family that is subactive in cation-exchange capacity. Gilpin and Shelocta soils are in families that are active in cation-exchange capacity. Gilpin, Muse, Petros, Sequoia, and Shelocta soils are in families with mixed mineralogy. Gilpin, Lily, and Sequoia soils are less than 40 inches deep to lithic or paralithic contact. Grimsley and Jefferson soils have thinner solums.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained with moderately rapid permeability.
USE AND VEGETATION: Nearly all sites are in hardwood forest consisting chiefly of oaks, hickories, yellow poplar, maples, dogwood, and a few shortleaf and Virginia pines.
DISTRIBUTION AND EXTENT: Along the edges of the Cumberland Plateau and Mountains in Tennessee and Kentucky, and possibly northern Alabama and Georgia. The series is of large extent including over 300,000 acres in Tennessee and Kentucky.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Hawkins County, Tennessee; 1974.
REMARKS: Diagnostic horizons recognized in this pedon are:
Ochric epipedon: From the surface of the soil to a depth of about 6 inches (A horizon)
Argillic horizon: From 11 to 83 inches (Bt horizon)
Samples submitted to NSSL for characterization including this pedon (042): S06TN061-041; S06TN061-042; S06TN133-043; & S07TN151-006. These sampling activiies lead to a change in cation-exchange activity class from subactive to semiactive. Readings were .23,.25,.27, & .3 respectively.