LOCATION COGHILL TNEstablished Series
TAXONOMIC CLASS: Fine, mixed, semiactive, thermic Typic Hapludults
TYPICAL PEDON: Coghill sandy loam-forested. (Colors are for moist soil.)
Oe--0 to 1 inch; partially decomposed hardwood and evergreen litter.
A--1 to 5 inches; brown (10YR 4/3) sandy loam; moderate medium granular structure; very friable; many fine and medium, common coarse roots; strongly acid; clear smooth boundary. (1 to 7 inches thick)
BE--5 to 7 inches; dark yellowish brown (10YR 4/6) sandy loam; weak fine granular structure; very friable; many fine and medium, few coarse roots; strongly acid; clear wavy boundary. (0 to 6 inches thick)
Bt1--7 to 19 inches; yellowish red (5YR 5/6) clay with common medium distinct strong brown (7.5YR 5/8) mottles; strong medium subangular blocky structure; friable; few fine and medium roots; many distinct clay films on faces of peds and in pores; strongly acid; abrupt smooth boundary.
Bt2--19 to 29 inches; yellowish red (5YR 5/8) clay with many medium prominent brownish yellow (10YR 6/8) mottles; moderate medium subangular blocky structure; friable; few fine roots; many distinct clay films on faces of peds and in pores; very strongly acid; abrupt smooth boundary.
BCt--29 to 38 inches; yellowish red (5YR 5/8) sandy clay loam with many coarse prominent yellowish brown (10YR 5/8) mottles; weak medium subangular blocky structure; friable; few fine roots; common faint yellowish red (5YR 5/6) clay films on faces of peds; very strongly acid; abrupt smooth boundary. (Combined thickness of the argillic horizon is 15 to 38 inches)
C1--38 to 58 inches; brownish yellow (10YR 6/8) sandy loam with common medium prominent yellowish red (5YR 5/8) mottles; massive structure; friable; very strongly acid; clear smooth boundary.
C2--58 to 78 inches; brownish yellow (10YR 6/8) loamy sand with few medium prominent yellowish red (5YR 5/8) mottles; massive structure; friable; very strongly acid. (Combined thickness of the C horizon is 21 to more than 40 inches)
TYPE LOCATION: McMinn County, Tennessee; 2.25 miles west of Etowah on County Road 660 to Goodsprings church, 2.3 miles south on County Road 609, east 875 feet on County Road 805, northeast 1500 feet along the ridge crest of Little Mountain in mixed forest. Etowah Quadrangle 35 degrees 18 minutes 06 seconds North latitude and 84 degrees 33 minutes 41 seconds West longitude.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 20 to 40 inches. Depth to hard bedrock is more than 60 inches. Rock fragments are channers and gravels of decalcified calcareous sandstone, quartzose limestone, and shale and range from 0 to 15 percent in the A and B horizons, and up to 35 percent in th BC and C horizons. Reaction ranges from very strongly acid to moderately acid, unless limed.
The A horizon has hue of 5YR to 10YR, value of 3 to 5, and chroma of 3 or 4. Texture of the fine-earth fraction is loam, sandy loam, or fine sandy loam. Where both value and chroma are 3, the horizon is less than 7 inches thick.
The BE horizon has hue of 5YR to 10YR, value of 4 or 5, and chroma of 4 to 6. Texture of the fine-earth fraction is loam, sandy loam, or fine sandy loam.
The Bt horizon has hue of 2.5YR to 7.5YR, value of 4 to 6, and chroma of 4 to 8. Mottles, where present, are in shades of red, yellow, or brown. Texture of the fine-earth fraction is clay, sandy clay, sandy clay loam, or clay loam. Some Bt horizons formed in shale layers and have a noticeable decrease of sand in the fine-earth fraction.
The BCt horizon has hue of 2.5YR to 7.5YR, value of 4 or 5, and chroma of 6 to 8. Mottles and clay films are in shades or red, yellow, or brown. Texture of the fine-earth fraction is sandy clay loam, clay loam, or clay.
The C horizon has hue of 5YR to 10YR, value of 4 to 6, and chroma of 4 to 8. Mottles are in shades of red, yellow, or brown. Texture of the fine-earth fraction is sandy loam, loam, loamy sand, clay loam, or sandy clay loam. A lithologic discontinuity occurs below the control section in pedons where the soil weathered through interbedded materials. The 2BC or 2C horizons, where present, have the same colors and textures as the C horizon, but have platy relict rock structure and/or variegated colors indicative of the parent materials.
COMPETING SERIES: These are currently the Albertville, Badin, Brockroad, Carnasaw, Catharpin, Corryton, Luverne, Masada, Mayodan, McQueen, Nason, Peakin, Sweatman, Tatum, Townley, Uwharrie, and Vance series. Soils in related families include the Fluvanna, Mattaponi, Noah, and Williamsville series. Albertville, Carnasaw, Fluvanna, and Noah soils have a paralithic contact at 40 to 60 inches. Badin and Townley soils have a paralithic contact at 20 to 40 inches. Brockroad and Catharpin soils have a lithologic discontinuity at 24 to 50 inches of alluvium over residuum. Corryton soils formed entirely in shale or siltstone, and have a higher content of silt, and less sand throughout. Luverne soils contain mica flakes. Masada soils contain mica flakes, coarse fragments of quartz, quartzite, gneiss or schist. Mattaponi soils formed in Coastal Plain sediments. Mayodan and Peakin soils formed in residuum from Triassic materials in the Southern Piedmont. McQueen soils formed in fluvial sediments and are on stream terraces. Nason soils have 25 to 50 inch sola and contain quartz and schist fragments. Sweatman soils contain mica flakes. Tatum soils contain schist fragments and have a paralithic contact with weathered schist. Uwharrie soils formed in residuum from slate, phyllite, or sericite schist in the Southern Piedmont. Vance soils have C horizons of saprolite weathered from felsic crystalline rock. More competitors will become apparent as more series are reclassified.
GEOGRAPHIC SETTING: Coghill soils are on gently sloping to very steep upland ridges and side slopes. These soils are commonly adjacent to areas of soils that have rhodic colors. They formed in residuum from Ordovician-aged limestones, shales, and sandstones. Common geologic formations include the Holston limestone, Chapman Ridge sandstone, and Ottosee shale. Near the type location, mean annual temperature is 57 degrees F. and mean annual precipitation is 56.5 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alcoa, Corryton, Neubert, Steekee, and Tellico series, and the tentative Red Hills series. Alcoa soils are in a Rhodic subgroup and Tellico soils are in a Rhodic great group. Additionally, Alcoa soils are on foot slopes and stream terraces. Corryton soils are on similar landscape positions, but formed entirely in shale residuum, and have less sand throughout the subsoil. Neubert soils are on adjacent narrow floodplains. Steekee soils are on nearby side slopes and ridge tops and are in a shallow family. Tellico soils are on adjacent gently sloping to very steep ridge tops and side slopes. Red Hills soils are on adjacent side slopes, do not have an argillic horizon, and are moderately deep.
DRAINAGE AND PERMEABILITY: Coghill soils are well drained. Permeability is moderate or moderately slow. Runoff is medium.
USE AND VEGETATION: Coghill soils are used mainly for woodland and pasture. Common trees are red oak, hickories, red maple, Virginia pine, and shortleaf pine. Some harvested areas are replanted in loblolly pines. A few areas have been cleared and abandoned.
DISTRIBUTION AND EXTENT: Southern Appalachian Ridges and Valleys (MLRA 128) in Tennessee and possibly Georgia and Alabama. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: McMinn County, Tennessee; 1999.
REMARKS: Coghill soils were correlated as loam surface phases of the Litz series in older soil surveys and with the Tellico series in more recent soil surveys. The 7/00 revision expands the range of characteristics to allow a lithologic discontinuity below the control section where the soil has weathered through interbedded materials.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 1 to 7 inches
Argillic horizon - 7 to 38 inches
SIR Number: TN1301