LOCATION HILLWOOD TNEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, semiactive, thermic Typic Paleudalfs
TYPICAL PEDON: Hillwood gravelly silt loam--pasture
Ap- 0 to 5 inches, dark reddish brown (5YR 3/4) gravelly silt loam; moderate fine and medium granular structure; very friable; many fine roots; few fine black concretions; about 20 percent 0.25 to 2 inch rounded pebbles of chert; strongly acid; clear smooth boundary. (3 to 10 inches thick)
BA- 5 to 9 inches, reddish brown (5YR 4/4) gravelly silty clay loam; moderate medium subangular blocky structure; friable; common fine roots; few fine black concretions; about 20 percent 0.25 to 2 inch rounded pebbles of chert; strongly acid; gradual smooth boundary. (3 to 12 inches thick)
Bt1- 9 to 27 inches, yellowish red (5YR 4/6) very gravelly silty clay loam; moderate fine and medium subangular and angular blocky structure; friable; common fine roots; common distinct clay films; common fine black concretions; about 50 percent 0.25 to 2 inch rounded pebbles of chert; strongly acid; gradual smooth boundary.
Bt2- 27 to 43 inches, yellowish red (5YR 4/6) very gravelly clay; moderate fine and medium angular blocky structure; friable; few fine roots; many distinct clay films; common fine black concretions; about 60 percent 0.25 to 3 inch rounded pebbles of chert; strongly acid; gradual smooth boundary.
Bt3- 43 to 62 inches, red (2.5YR 4/6) very gravelly clay; weak fine and medium angular blocky structure; friable; few fine roots; few distinct clay films; common fine black concretions; about 70 percent 0.25 to 2 inch rounded pebbles of chert; medium acid; clear wavy boundary.(combined thickness of the Bt horizon is 24 to 64 inches.)
2Bt4- 62 to 70 inches, strong brown (7.5YR 5/6) clay: common fine and medium distinct red (2.5YR 4/8), pale brown (10YR 6/3), and reddish brown(5YR 4/4) mottles; weak medium and coarse angular blocky structure; firm; few faint clay films; few fine dark brown and black concretions; few 0.25 to 2 inch pebbles of chert; slightly acid.
TYPE LOCATION: Rutherford County Tennessee; 1 mile east of Compton; 0.5 miles west of East Fork Stone River; 1000 feet east of intersection of Compton Road and Shady Lane; 50 feet south of fence corner.
RANGE IN CHARACTERISTICS: The thickness of the solum and depth to bedrock is greater than 60 inches. Gravel content ranges from 15 to 35 percent in the Ap, BA, and 2Bt horizons, and from 35 to 80 percent in the Bt horizon. Most of the gravel are 0.25 to 3 inches in diameter. Reaction ranges from strongly acid to slightly acid in each horizon.
The Ap horizon has hue of 10YR to 5YR, value of 3 or 4 and chroma of 3 or 4. Where the Ap horizon is thicker than 6 inches, the color value is 4 or more. The fine earth fraction is a silt loam. In severely eroded areas the Ap has hue of 7.5YR or 5YR, value of 4 or 5, and chroma of 6. The fine earth fraction is a silty clay loam.
The BA horizon, present in most pedons, has colors and textures transitional to that of the Ap and Bt horizons.
The Bt horizon has hue of 5YR or 2.5YR, value of 4 or 5 and chroma of 3 to 6. The fine earth fraction is a silt clay loam, clay loam, or clay. The clay content ranges from 35 to 60 percent.
The 2Bt horizon has hue of 10YR to 5YR, value of 5, and chroma of 4 and 6. Mottles are in shades of brown, yellow, or red. The fine earth fraction is clay.
COMPETING SERIES: There are no other series in this family. Soils in similar families are the Bodine, Braxton, Craig, and Etowah series. Bodine soils have loamy-skeletal control sections and less than 35 percent base saturation. Braxton soils have fine control sections. Craig soils have surface horizons more than 6 inches thick with moist color values less than 4. Etowah soils have fine loamy control sections with less than 15 percent gravel and have less than 35 percent base saturation.
GEOGRAPHIC SETTING: Hillwood soils are on high stream terraces, alluvial fans, and toeslopes. Slopes range from 2 to 20 percent. The soil formed in thick deposits of old alluvium that has a high content of gravel and is underlain in most places by clayey limestone residuum. The average annual rainfall ranges from 45 to 52 inches, and the mean annual temperature is about 60 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bradyville, Cumberland, Emory, Pembroke, and Talbott series. All of these series contain less than 35 percent gravel in their control sections. In addition, Emory and Pembroke soils contain less than 35 percent clay in their control sections.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium and permeability is moderately rapid.
USE AND VEGETATION: Most areas of this soil have been cleared and are used as pasture. Forested areas are chiefly oak, hickory, elm, hackberry, and red cedar.
DISTRIBUTION AND EXTENT: The Inner Central Basin of Tennessee. It is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Rutherford County, Tennessee; 1974.
REMARKS: Diagnostic horizon and features recognized in the pedon are:
Ochric epipedon - from 0 to 5 inches (Ap horizon).
Argillic horizon - from 9 to 70 inches (Bt and 2Bt horizons).