LOCATION ZILLICOA NCEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, mesic Vertic Hapludalfs
TYPICAL PEDON: Zillicoa loam, 8 percent slope-forested. (Colors are for moist soil unless otherwise stated)
Oe--0 to 1 inches; very dark brown (10YR2/2) partially decomposed plant material; deciduous leaves, twigs, and roots; primarily deciduous leaf litter; very friable; strongly acid; abrupt wavy boundary.
A--1 to 5 inches; very dark grayish brownish (10YR 3/2) loam, dark yellowish brown (10YR 4/4) dry; weak fine and medium granular structure; very friable; many fine to medium and few coarse roots throughout; common fine to coarse interstitial pores; few fine rounded iron-manganese concretions; moderately acid; 2% by volume pebbles, 6% by volume cobbles, 2% by volume stones that are coarse grained garnet hornblende fels; clear smooth boundary. (3 to 8 inches thick)
BA--5 to 10 inches; dark yellowish brown (10YR 4/4) loam; few fine and medium distinct strong brown (7.5YR 4/6) mottles; moderate fine and medium granular structure; friable, slightly sticky, non-plastic; common fine and medium roots throughout; common fine to coarse tubular and interstitial pores; many fine very dark brown (10YR 2/2) iron-manganese masses on faces of peds; few rounded iron-manganese concretions; slightly acid; 4% by volume pebbles, 2% volume cobbles, 2% by volume stones that are coarse grained garnet hornblende fels; gradual wavy boundary. (0 to 10 inches thick)
Bt--10 to 20 inches; dark yellowish brown (10YR 4/6) clay; few medium distinct strong brown(7.5YR 5/6) mottles; moderate medium subangular blocky structure; firm, sticky, plastic; few fine and medium roots between peds; few fine and medium interstitial and common fine tubular pores; few faint discontinuous yellowish brown (10YR 5/6) clay films, and common fine very dark brown (10YR 2/2) iron-manganese masses on faces of peds and in pores; moderately acid; gradual wavy boundary.
Btss--20 to 34 inches; yellowish brown (10YR 5/6) clay; strong medium subangular blocky structure; very firm, very sticky, very plastic; few very fine roots between peds; few very fine and fine tubular pores; common striated and polished slickensides, 7 to 10 cm wide and 5 to 15 cm long; many faint continuous yellowish brown (10YR 5/4) clay films on faces of peds, and common medium very dark brown (10YR 2/2) discontinuous manganese or iron-manganese masses; common fine cylindrical iron-manganese concretions; neutral; gradual wavy boundary.
B't--34 to 37 inches; dark yellowish brown (10YR 4/6) clay; moderate medium subanglar blocky structure; very firm, sticky, very plastic; few very fine roots between peds; few very fine tubular pores; many faint continuous clay films, and medium very dark brown (10YR 2/2) discontinuous iron-manganese masses on faces of peds; many fine rounded iron-manganese concretions; neutral; gradual irregular boundary. (Combined thickness of Bt is 10 to 40 inches)
BC--37 to 49 inches; dark yellowish brown (10YR 4/4) sandy clay loam; few medium distinct reddish yellow (7.5YR 6/8) mottles; moderate fine and medium subangular blocky structure; friable, non-sticky, non-plastic; few very fine and fine roots between peds; common very fine tubular pores; very few faint discontinuous clay films on faces of peds, and few medium very dark brown (10YR 2/2) iron-manganese masses; many fine rounded iron-manganese concretions; neutral; gradual wavy boundary. (5 to 15 inches thick)
Cr--49 to 60 inches; multicolored, weathered coarse grained garnet hornblende fels bedrock that can be dug with difficulty with a spade; partly consolidated in place; few very fine tubular pores; bedrock fragments have black (10YR 2/1) manganese masses; neutral.
TYPE LOCATION: Buncombe County, North Carolina; 0.2 mile north of Alexander on North Carolina Highway 251; 1.2 miles west on Secondary Road 1634; 0.2 mile northeast on Knoll Top Road (private road); 100 feet northwest in wooded area. Leicester USGS topographic quadrangle; Latitude: 35-41'-50" N; Longitude: 82-38'-05" W
RANGE IN CHARACTERISTICS: The solum thickness ranges from 40 to 60 inches. Depth to paralithic contact with weathered bedrock (Cr) is 40 to 60 inches. Depth to lithic contact with hard, unweathered bedrock (R) is more than 60 inches. Rock fragment content is less than 35 percent throughout. Fragments range in size from gravel to stones in the upper horizons and are dominantly gravel in the lower horizons. Reaction is strongly acid through slightly acid in the upper horizons and moderately acid to slightly alkaline in the lower horizons. Base saturation by sum of cations is 35 to 60 percent at 1.25 meters below the top of the argillic horizon. Black manganese concretions range from few to many in some horizons of most pedons. COLE measured 7.2 cm in the upper meter.
The A or Ap horizon has hue of 7.5YR to 2.5Y, value of 3 to 6, and chroma of 2 to 6. Where value is 2 or 3, the horizon is less than 6 inches thick. Texture is sandy loam, fine sandy loam, and loam in fine-earth fraction. In eroded phases the Ap horizon is clay loam or sandy clay loam in the fine-earth fraction.
The E horizon, where present, has hue of 10YR or 2.5Y, value of 3 to 6, and chroma of 2 to 4. Texture is sandy loam, fine sandy loam, and loam in fine-earth fraction.
The BA or BE horizons, where present, has hue of 7.5YR to 2.5Y, value of 4 to 6, and chroma of 3 to 8. Texture is sandy loam, fine sandy loam, loam, or sandy clay loam in fine-earth fraction.
The Bt horizons have hue of 7.5YR to 2.5Y, value of 4 to 6, chroma of 4 to 8. Mottles of high and low, non-redoximorphic chromas are in lower Bt horizons of some pedons. Texture is clay or clay loam.
The Bss horizon has colors and textures similar to the Bt horizon. Slickensides are at least 5 cm long and 5 cm wide. Bss horizon is at least 6 inches thick.
The B't horizon, where present, has hue of 7.5YR to 2.5Y, value of 4 to 6, chroma of 4 to 8. Texture is clay or clay loam.
The BC or CB horizon, where present, has hue of 7.5YR to 5Y, value of 3 to 6, chroma of 3 to 8. Texture is clay loam, sandy clay loam, sandy loam, or loam.
The C horizon, where present, is multicolored saprolite weathered from ultramafic, mafic, or intermediate rock. Texture is sandy loam, fine sandy loam, loam, sandy clay loam, and clay loam.
The Cr horizon is multicolored, weathered hornblende schist bedrock.
COMPETING SERIES: There are no other series in this family. Series in related families are the Carmel, Gladdice, Ladoga, McKamie, and Pate series. Carmel, Ladoga, and Pate soils formed in limestone, calcareous shale, and/or loess material in the Midwest. Gladdice soils formed in limestone and McKamie soils formed in clayey alluvial sediments on stream terraces. Both have a thermic soil temperature regime.
GEOGRAPHIC SETTING: Zillicoa soils are gently sloping to moderately steep and are on ridge summits and side slopes of intermountain hills in the Southern Appalachian Mountains. Elevation ranges from about 1800 to 3000 feet. Slopes are generally between 2 and 15 percent but range from 2 to 30 percent. The soils formed in residuum from coarse grained garnet hornblende fels. Mean annual temperature ranges from 46 to 57 degrees F. Mean annual precipitation ranges from 30 to 50 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Braddock, Clifton, Cowee, Evard, Marshill, Oteen, Tate, Unison, and Walnut series. Except for Marshill, Oteen, and Walnut, these soils have less than 35 percent base saturation. Marshill, and Walnut soils are coarse loamy, and Oteen is loamy. Walnut and Oteen have weathered bedrock at depths 20 to 40 inches and 10 to 20 inches, respectively. Cowee, Evard, and Tate soils are fine-loamy and have argillic horizons of 18 to 35 percent clay in the subsoil. Braddock, Clifton, and Unison soils are clayey and have argillic horizons with more than 35 percent clay in the subsoil. All of these soils except for Braddock, Tate, and Unison are on similar residual landscape positions. Braddock and Unison soils are on broad, high terraces. Tate soils are on benches, fans, and toe slopes in coves.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability; slow internal drainage. Runoff class is moderate on gentle and strong slopes and rapid on moderately steep slopes. Runoff is lower where forest cover is intact.
USE AND VEGETATION: Cleared areas are used primarily for pasture or hay production. Forage crops include orchardgrass, red clover, lespedeza, tall fescue, and bluegrass. Forested areas include Virginia pine, eastern white pine, shortleaf pine, white oak, chestnut oak, scarlet oak, black oak, and hickory. Mountain laurel, flowering dogwood, sourwood, and black locust are common in the understory. A small acreage is used for burley tobacco and small grain.
DISTRIBUTION AND EXTENT: Southern Appalachian Mountain regions of North Carolina, and possibly Georgia, South Carolina, Virginia, and Tennessee. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES PROPOSED: Buncombe County, North Carolina, 1999.
REMARKS: Previously included in mapping of Enon Variant or Clifton soils
DIAGNOSTIC HORIZONS & FEATURES recognized in the typical pedon are:
Ochric epipedon - the zone from the surface to a depth of 5 inches (Oe, A, and E horizons)
Argillic horizon - the zone between depths of 5 and 37 inches (Bt, Btss, and Bt' horizons)
Vertic feature - linear extensibility for the upper meter is 7.2 cm. Shrink-swell properties are enhanced due to the high proportion of fine clay (80% of total clay is fine clay)
Paralithic contact - weathered coarse grained garnet hornblende fels bedrock at a depth of 49 inches (upper boundary of the Cr horizon)
ADDITIONAL DATA: Characterization data is available from the National Soil Survey Laboratory, Lincoln, NE; Pedon number: S90NC-021-001
NASIS DATA MAPUNIT:
MLRA = 130