LOCATION VARILLA KY+PA+TN+VA+WV
Established Series
REV.JDC-WHC-JDM
12/2021
VARILLA SERIES
The Varilla series consists of deep and very deep, somewhat excessively drained soils on hills and mountains. They formed in stony, loamy colluvium or residuum weathered primarily from sandstone. Slopes range from 5 to 90 percent.
TAXONOMIC CLASS: Loamy-skeletal, siliceous, semiactive, mesic Typic Dystrudepts
TYPICAL PEDON: Varilla gravelly fine sandy loam--on a 60 percent southwest facing slope with an overstory of oak, maple, and pines and an understory of mountain laurel, rhododendron and sourwood.
Oi--0 to 2 inches; partially decomposed leaves, roots, and twigs; extremely acid; abrupt wavy boundary.
A--2 to 5 inches; very dark grayish brown (10YR 3/2) gravelly fine sandy loam; moderate very fine granular structure; very friable; many very fine roots throughout; 30 percent rock fragments; extremely acid; abrupt wavy boundary. (1 to 7 inches thick)
Bw1--5 to 12 inches; yellowish brown (10YR 5/4) gravelly fine sandy loam; weak fine subangular blocky structure; very friable; common medium roots throughout; 25 percent rock fragments; very strongly acid; clear wavy boundary.
Bw2--12 to 22 inches; yellowish brown (10YR 5/4) very cobbly fine sandy loam; weak medium subangular blocky structure; friable; common fine roots throughout; 40 percent rock fragments; extremely acid; clear wavy boundary.
Bw3--22 to 36 inches; yellowish brown (10YR 5/4) very cobbly fine sandy loam; weak medium subangular blocky structure; friable; few fine roots throughout; 50 percent rock fragments; extremely acid; gradual wavy boundary.
Bw4--36 to 47 inches; yellowish brown (10YR 5/4) extremely cobbly fine sandy loam; weak fine subangular blocky structure; friable; few fine roots throughout; 65 percent rock fragments; very strongly acid; gradual wavy boundary. (Combined thickness of Bw is 39 to 48 inches).
BC--47 to 66 inches; yellowish brown (10YR 5/6) extremely cobbly loamy sand; weak fine subangular blocky structure; very friable; common medium roots throughout; 70 percent rock fragments; few distinct strong brown (7.5YR 4/6) clay films on faces of peds; very strongly acid. (0 to 24 inches thick).
TYPE LOCATION: Bell County, Kentucky; on the dip slope of Pine Mountain in Yellow Cliff Branch; .2 mile northwest of the confluence of Yellow Cliff Branch and the Cumberland River; .9 mile west-northwest of the community of Miracle and about 5.5 miles E of Pineville via Kentucky Highway 119; 36 degrees, 45 minutes, 52.5 seconds N. latitude and 83 degrees, 36 minutes, 2.8 seconds W. Longitude; USGS Balkan Topographic Quadrangle; NAD 83.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 40 to 60 inches or more. Depth to bedrock ranges from 48 to 60 inches or more. The control section averages 5 to 17 percent clay and less than 60 percent silt. Rock fragments, mostly sandstone gravels, cobbles and stones, make up 15 to 75 percent of the solum and 35 to 90 percent of the C horizon. Reaction is extremely acid to strongly acid throughout, except a few A horizons that range to slightly.
The A horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 2 or 3. Some pedons have a thin A horizon with value of 3 and chroma of 1 to 3. Texture of the fine-earth is sandy loam, fine sandy loam, loam, or silt loam.
The Bw horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 4 to 6. Texture of the fine-earth is sandy loam, fine sandy loam, loam, or silt loam.
The BC horizon and C horizon (where present) has hue of 7.5YR or 10YR, value of 5 to 7, and chroma of 3 to 6. Texture of the fine-earth is sand, loamy sand, sandy loam, fine sand, loamy fine sand, fine sandy loam, or loam.
COMPETING SERIES: These are the established
Lehew and the tentative
Layland and
Marbleyard Series. Lehew soils have a lithic contact at a depth less than 40 inches. Marbleyard soils formed in materials weathered from low-grade metasedimentary quartzite and metasandstone.
GEOGRAPHIC SETTING: Varilla soils formed in areas dominated by sandstone Rock outcrop on the lower two-thirds of hills or mountains. Slopes are dominantly 35 to 75 percent, but range from 5 to 90 percent. Elevation ranges from about 600 to 3,800 feet. Mean annual temperature ranges from 48 to 57 degrees F. with a mean of 54 degrees. Mean annual precipitation ranges from 43 to 55 inches with mean of about 53 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Alticrest,
Bouldin,
Grimsley,
Jefferson,
Lily,
Helechawa,
Ramsey,
Totz,
Shelocta and
Wallen soils. Alticrest and Helechawa soils are coarse-loamy. Bouldin, Grimsley, Jefferson, Lily and Shelocta soils have argillic horizons. Alticrest, Lily, and Wallen soils are moderately deep. Ramsey and Totz soils are shallow.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained with moderately rapid permeability.
USE AND VEGETATION: Most areas are in second growth forest with mixed stands of eastern hemlock, white oak, yellow-poplar, chestnut oak, American beech, scarlet oak, pitch pine, Virginia pine, and hickory. Minor species include red maple, northern red oak, black oak, black gum, sourwood, and black cherry. A few of the less sloping areas are used for pasture and sites for houses and gardens.
DISTRIBUTION AND EXTENT: Varilla soils are in the Cumberland Plateau and Cumberland Mountains Section of the Appalachian Plateaus Province and in the Highland Rim Section of the Interior Low Plateaus Province of the Interior Plains (MLRAs 125 & 120A). The series is estimated to be of moderate extent, about 50,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Bell County, Kentucky, 1989.
REMARKS: Varilla soils were previously mapped as the stony phases of Jefferson and Tate soils.
Diagnostic horizons recognized in this pedon are:
Ochric epipedon-0 to 3 inches (A horizon).
Cambic horizon-3 to 64 inches (Bw & BC horizons).
12/2021 revision: Oi had 2 to 0 inch depths, corrected to be 0 to 2 in horizon depths then added 2 inches to all horizon depths throughout the typical pedon.
ADDITIONAL DATA: Characterization sample S85KY-13-4 (typical pedon) and reference sample S84KY-13-4 by NSSL. Characterization sample S07-VA-051-001 by Plant and Soil Sciences Department, University of Kentucky.
National Cooperative Soil Survey
U.S.A.