LOCATION STAINKY                 AK

Established Series
Rev. MHC/JPM
02/2022

STAINKY SERIES

The Stainky series consists of very deep, well drained soils formed in an admixture of loess and silty glacial outwash underlain by friable to firm very gravelly glacial till. Stainky soils are on glacial till plains. Slopes range from 0 to 25 percent. The mean annual temperature is about 35 degrees F. and the mean annual precipitation is about 18 inches.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Typic Haplocryods

TYPICAL PEDON: Stainky silt loam - on a west facing slope of 4 percent at 300 feet elevation under white spruce and paper birch. (All colors are for moist soil)

Oi--2 inches to 0; undecomposed moss and forest litter. (1 to 4 inches thick)

E--0 to 1 inch; gray (10YR 5/1) silt loam; weak fine subangular blocky structure; very friable, nonsticky and nonplastic; many very fine, fine, medium, and coarse roots; strongly acid (pH 5.2); abrupt irregular boundary. (1 to 3 inches thick)

Bs--1 to 4 inches; dark yellowish brown (10YR 4/6) cobbly silt loam; weak fine subangular blocky structure; very friable, nonsticky and nonplastic; common medium faint yellowish brown (10YR 5/4) and common medium distinct strong brown (7.5YR 4/6) mottles; 5 percent gravel and 15 percent cobble; common very fine and medium roots; moderately acid (pH 5.6); clear irregular boundary. (3 to 6 inches thick)

BC--4 to 10 inches; dark yellowish brown (7.5YR 5/6) silt loam; weak fine subangular blocky structure; very friable, nonsticky and nonplastic; many medium faint (2.5Y 5/4) and common medium faint (7.5YR 4/6) mottles; 5 percent cobble and 5 percent gravel; very fine, fine and medium roots; moderately acid (pH 5.6); gradual wavy boundary. (2 to 6 inches thick)

C--10 to 23 inches; dark yellowish brown (10YR 4/4) silt loam and loam; weak fine subangular blocky structure; very friable, nonsticky and nonplastic; many medium distinct dark grayish brown (10YR 4/2) and dark yellowish brown (10YR 3/6) mottles; 5 percent gravel and 5 percent cobble; few very fine roots; moderately acid (pH 5.8); abrupt smooth boundary. (4 to 14 inches thick)

Eb--23 to 26 inches; grayish brown (10YR 5/2) silt loam; weak fine subangular blocky structure; very friable, nonsticky and nonplastic; common medium distinct dark yellowish brown (10YR 3/4) mottles; 5 percent gravel and 5 percent cobble; strongly acid (pH 5.2) abrupt smooth boundary. (0 to 3 inches thick)

Bsb--26 to 28 inches; dark brown (7.5YR 3/4) silt loam; massive; very friable, nonsticky and nonplastic; common medium faint dark yellowish brown (10YR 3/6) mottles; 5 percent gravel and 5 percent cobble; strongly acid (pH 5.2) abrupt smooth boundary. (0 to 6 inches thick)

C1--28 to 35 inches; dark yellowish brown (10YR 4/4) loam; massive; very friable, nonsticky and nonplastic; common medium distinct dark grayish brown (10YR 4/2) and dark yellowish brown (10YR 3/6) mottles; 5 percent gravel and 5 percent cobble; moderately acid (pH 5.6); clear smooth boundary. (0 to 14 inches thick)

2C2--35 to 60 inches; olive brown (2.5Y 4/4) very gravelly loam; friable, slightly sticky and slightly plastic; 35 percent gravel and 10 percent cobble; slightly acid (pH 6.2).

TYPE LOCATION: Matanuska Valley Area, Alaska: about 10 miles west of Wasilla; about 900 feet S. and 100 feet W. of the NW corner of section 35, T.18N., R.4W., Seward Meridian.

RANGE IN CHARACTERISTICS: MAST ranges from 33 to 36 degrees F. Some profiles may be bisequal. The upper solum ranges in thickness from 6 to 15 inches. The upper part of the particle-size control section is an admixture of loess and glacial outwash material 18 to 37 inches thick and averages 5 to 25 percent rock fragments. The lower part of the control section is loamy-skeletal and averages 35 to 50 percent rock fragments. Reaction ranges from strongly acid to moderately acid in the solum and moderately acid to neutral in the substratum.

The E and Eb horizons have moist value of 4 or 5 and moist chroma from 1 through 3.

The Bs and Bsb horizons have moist hue of 7.5YR or 10YR, moist value of 3 or 4 and moist chroma of 4 through 6. Textures include silt loam and loam with 0 to 10 percent cobble and 5 to 15 percent gravel.

The BC and C horizons have moist hue from 7.5YR to 2.5Y, moist value from 3 to 5 and moist chroma from 3 to 6. Textures include silt loam and loam with 0 to 10 percent cobble and 5 to 15 percent gravel.

The 2C horizons have moist hue of 10YR or 2.5YR, moist value of 3 or 4 and moist chroma from 2 through 4. Textures include sandy loam and loam. Rock fragment content ranges from 0 to 5 percent stone, 0 to 20 percent cobble and 25 to 45 percent gravel.

COMPETING SERIES: These are the Barlow, Flat Horn, Hartnit, Oso, Timberly and Yohn(T) series in the same family. Barlow soils have MAST greater than 40 degrees F. Flat Horn soils are dominated by amorphous material in the solum and are stratified in the substratum. Hartnit and Oso soils are 20 to 40 inches deep over bedrock. Timberly soils have A horizons. Yohn soils have strata of fine sand and silt.

GEOGRAPHIC SETTING: The Stainky soils occur on glacial till plains. Slopes range from 0 to 25 percent. These soils formed in an admixture of loess and silty glacial outwash material underlain by friable or firm glacial till material. Climate is transitional maritime - continental. Mean annual temperature ranges from 32 to 36 degrees F. Mean annual precipitation ranges from 16 to 22 inches

DRAINAGE AND PERMEABILITY: Well drained. Medium to rapid runoff. Moderate permeability in the upper part, moderately slow below.

USE AND VEGETATION: Wildlife habitat, agriculture and urban uses. Native vegetation includes paper birch, white spruce, quaking aspen, bluejoint grass and low shrubs.

DISTRIBUTION AND EXTENT: Southcentral Alaska. The series is of moderate extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA

SERIES ESTABLISHED: Matanuska-Susitna Area, Alaska, 1996.

REMARKS: Diagnostic features and horizons recognized in this profile include: albic horizons at depths of 0 to 1 inch and 23 to 26 inches; spodic horizons at depths of 26 to 28 inches; a layer from 0 to 35 inches consisting of and admixture of loess and glacial outwash with coarse-loamy particle size; glacial till material with loamy-skeletal particle size from 35 to 60 inches; cryic temperature regime.

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National Cooperative Soil Survey
U.S.A.