LOCATION TEKISON WAEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Ultic Palexerolls
TYPICAL PEDON: Tekison stony loam, forested. (Colors are for dry soil unless otherwise noted.)
0e--0 to 1 inch; partially decomposed forest litter.
A--1 to 8 inches; dark brown (10YR 3/3) stony loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common fine, medium, and coarse roots; common fine and many very fine tubular pores; 10 percent gravel and 5 percent stones over the surface; moderately acid (pH 5.8); abrupt smooth boundary. (4 to 16 inches thick)
AB--8 to 15 inches; dark yellowish brown (10YR 4/4) extremely cobbly clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few coarse and common medium and fine roots; few fine and many very fine tubular pores; 25 percent gravel, 35 percent cobbles, and 5 percent stones; moderately acid (pH 6.0); abrupt smooth boundary. (7 to 10 inches thick)
Bt1--15 to 27 inches; dark yellowish brown (10YR 4/4) extremely cobbly clay, brown (10YR 4/3) moist; strong medium angular blocky structure; very hard, very firm, moderately sticky and very plastic; common medium and fine roots and common very fine tubular pores; many prominent clay films on faces of peds; 45 percent gravel, 20 percent cobbles, and 5 percent stones; moderately acid (pH 5.8); abrupt smooth boundary. (7 to 15 inches thick)
Bt2--27 to 46 inches; yellowish brown (10YR 5/4) extremely gravelly clay, dark yellowish brown (10YR 4/4) moist; strong medium angular blocky structure; very hard, very firm, moderately sticky and very plastic;few fine and medium roots; common very fine tubular pores; continuous prominent clay films on faces of peds; 50 percent gravel, 20 percent cobbles, and 5 percent stones; moderately acid (pH 5.8); clear smooth boundary. (10 to 22 inches thick)
Bt3--46 to 61 inches; yellowish brown (10YR 5/4) extremely gravelly clay, dark brown (10YR 3/3) moist; strong medium angular blocky structure; very hard, very firm, moderately sticky and moderately plastic; few fine and medium roots; common very fine tubular pores; many prominent clay films on faces of peds; 50 percent gravel, 20 percent cobbles, and 5 percent stones; moderately acid (pH 6.0).
TYPE LOCATION: Kittitas County, Washington; about 10 miles north of Ellensburg; 200 feet south and 100 feet west of northeast corner, section 12, T.19N., R.E., WM.
RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry in the moisture control section for 75 to 90 consecutive days following summer solstice in most years. The mollic epipedon is 10 to 20 inches in thickness. Organic matter content is assumed to be less than 1 percent below a depth of 20 inches. The mean annual soil temperature is 47 to 49 degrees F. The particle-size control section is 40 to 55 clay in the fine-earth fraction and 40 to 70 percent rock fragments by volume.
The A horizon has hue of 10YR or 7.5YR, value of 3 to 5 dry, 2 or 3 moist and chroma of 2 or 3 moist and dry. Reaction is neutral to moderately acid.
The AB horizon has hue of 7.5YR or 10YR, value of 4 or 5 dry and chroma of 2 or 3 moist, 2 to 4 dry. Texture is gravelly loam, gravelly clay loam, very cobbly loam, extremely cobbly clay loam, or very cobbly clay loam with 20 to 35 percent clay. Reaction is slightly acid or moderately acid.
The Bt horizon has hue of 10YR, 7.5YR or 5YR, value of 4 or 5 dry, 3 or 4 moist and chroma of 2 to 4 moist, 3 or 4 dry. Texture is very cobbly clay, extremely gravelly clay, extremely cobbly clay, or very gravelly clay with 40 to 55 percent clay. Reaction is slightly acid or moderately acid.
Some pedons have a BC horizon below the Bt horizon with color similar to the Bt horizon. Texture is very cobbly clay loam, very gravelly clay loam, or very cobbly clay with 35 to 45 percent clay. Reaction is slightly acid or moderately acid.
COMPETING SERIES: This is the
Forestay series. The
Hudspeth series is in a similar family. Hudspeth soils have frigid soil temperature regimes.
Forestay soils MAST of 53 to 59 degrees F.; dry for less than 75 consecutive days following the summer solstice; have a 2Bw horizon with very gravelly coarse sandy loam textures.
Hudspeth soils 20 to 40 inches to a lithic contact (argillite); frigid soil temperature regime
GEOGRAPHIC SETTING: Tekison soils are on broad ridge tops, south-facing mountain side slopes, benches and smooth mountain summits, plateaus, hillslopes and canyon side slopes. Slopes range from 0 to 65 percent. The soils formed in residuum and colluvium from vesicular Yakima basalt mixed with loess. Elevation is 800 to 4,400 feet. These soils are in a climate with warm, dry summers and cool, moist winters. The mean annual precipitation is 15 to 25 inches. The average January temperature is about 25 degrees F. and the average July temperature is about 68 degrees F. The mean annual temperature is 46 to 50 degrees F. The frost-free season is 120 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Clint, Meystre and Rock Creek soils. Clint soils have bedrock at a depth of 20 to 40 inches and are on uplands. Meystre soils are fine-loamy and are on uplands. Rock Creek soils are 4 to 10 inches deep to bedrock and are on ridge tops and plateaus.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability above the argillic horizon and slow through the argillic horizon.
USE AND VEGETATION: These soils are used for commercial woodland, grazeable woodland, recreation, wildlife habitat, and watershed. Native vegetation is mainly ponderosa pine, scattered Douglas-fir, pinegrass, elk sedge, lupine spirea, common snowberry, ribes, creambush oceanspray, Oregon-grape, and scattered antelope bitterbrush.
DISTRIBUTION AND EXTENT: South-central Washington. MLRA 6. Series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Yakima County, Washington, 1979.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 1 to 15 inches
Argillic horizon - the zone from 15 to 61 inches that has more than 20 percent, absolute, more clay than the AB horizon and an abrupt boundary
Particle-size control section - the zone from 15 to 35 inches