LOCATION MAXHILL WATentative Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Vitrandic Argixerolls
TYPICAL PEDON: Maxhill ashy loam- irrigated pasture, is on a 3 percent slope at an elevation of 1,680 feet. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 7 inches; dark grayish brown (10YR 4/2) ashy loam; very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure parting to moderate medium granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular and many very fine irregular pores; 10 percent gravel; NaF pH 8.5; neutral (pH 7.2); abrupt smooth boundary. (5 to 8 inches thick)
A--7 to 10 inches; dark grayish brown (10YR 4/2) ashy loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular and many very fine irregular pores; 10 percent gravel; NaF pH 8.5; neutral (ph 7.2); clear wavy boundary. (2 to 6 inches thick)
AB--10 to 13 inches; brown (10YR 4/3) gravelly ashy loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular and many very fine irregular pores; 20 percent pebbles; NaF pH 8.6; neutral (pH 7.2); common wavy boundary; (3 to 9 inches thick)
Bt--13 to 48 inches; brown (10YR 4/3) very gravelly sandy clay, dark brown (7.5YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly sticky and moderately plastic; few very fine roots; common very fine tubular and many very fine irregular pores; many distinct brown (7.5YR 4/3) clay films lining pores and on faces of peds; 35 percent gravel and 10 percent cobbles; NaF pH 8.6; neutral (pH 7.2); abrupt wavy boundary. (30 to 40 inches thick)
2BC--48 to 60 inches; brown (10YR 4/3) extremely gravelly loamy coarse sand, very dark brown (10YR 2/2) moist; single grain; loose, loose, nonsticky and nonplastic; few very fine roots; 55 percent gravel and 35 percent cobbles; NaF pH 8.3; neutral (pH 7.2).
TYPE LOCATION: Kittitas County, Washington; about 1 miles northwest of Thorp; about 2,100 feet west and 2,200 feet south of the northeast corner of section 3, T. 18 N., R. 17 E.; USGS Thorp, Washington topographic quadrangle; Latitude 47 degrees, 04 minutes, 54 seconds N. and Longitude 120 degrees, 41 minutes, 42 seconds W.
RANGE IN CHARACTERISTICS: The mean average annual soil temperature at a depth of 20 inches ranges from 47 to 52 degrees F. These soils are usually moist but are dry in the moisture control section for 90 to 100 consecutive days following the summer solstice. Thickness of mollic is 25 to 50 inches and includes part or all of the argillic horizon. The upper 10 to 25 inches has an estimated bulk density of 1.15 to 1.40 g/cc, volcanic glass content of 15 to 25 percent, acid oxalate extractable aluminum plus one-half of acid oxalate extractable iron of 0.25 to 0.6 percent, and 15-bar water retention of 5 to 10 percent for air dried samples. The particle-size control section has 35 to 40 percent clay and 35 to 80 percent rock fragments by volume. Organic matter is estimated to range from 2 to 4 percent in the Ap or A horizon. Depth to the Bt horizon is 11 to 20 inches. Depth to the 2BC horizon is 40 and 60 inches. Reaction is slightly acid or neutral.
The Ap and A horizons have value of 3 or 4 dry, 2 or 3 moist, chroma of 1 or 2 dry or moist. Texture of the Ap horizon is ashy loam, cobbly ashy loam, or very cobbly ashy loam. Texture of the A horizon is ashy loam, gravelly ashy loam, or very gravelly ashy loam or cobbly ashy loam. It has 5 to 30 percent gravel, 0 to 30 percent cobbles, and 0 to 5 percent stones.
The AB horizon has value of 3 or 4 dry, 2 or 3 moist, chroma of 2 or 3 dry or moist. Texture is gravelly ashy loam, very gravelly ashy loam, or cobbly ashy loam with 18 to 23 percent clay. It has 5 to 35 percent gravel and 0 to 10 percent cobbles.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry, 2 or 3 moist and chroma of 2 or 3 moist or dry. Texture is extremely gravelly sandy clay, extremely cobbly sandy clay, very gravelly sandy clay or very cobbly sandy clay with 35 to 40 percent clay. It has 20 to 55 percent gravel, 5 to 25 percent cobbles, and 0 to 3 percent stones.
The 2BC horizon has value of 4 or 5 dry, 2 or 3 moist, chroma of 2 or 3 dry or moist. Texture is extremely gravelly loamy coarse sand, extremely cobbly loamy sand or extremely gravelly loamy sand with 0 to 15 percent clay. It has 35 to 60 percent gravel, 15 to 40 percent cobbles, and 0 to 3 percent stones.
COMPETING SERIES: These are the
Modsel (T) and
Tanksel series.
Modsel soils 30 to 48 inches to aquic conditions and redox concentrations; dry for 60 to 75 consecutive days; lacks a 2BC horizon of extremely gravelly loamy coarse sand or loamy sand.
Tanksel soils 20 to 40 inches to lithic contact.
GEOGRAPHIC SETTING: Millhouse soils are on alluvial fans and terraces and have slopes of 0 to 5 percent. These soils formed in alluvium or outwash deposits with an influence of loess mixed with volcanic ash in the surface. Elevation is 1,700 to 3,100 feet. Here soils are in a semiarid climate with warm dry summers and cool moist winters. The mean annual precipitation is 12 to 16 inches. The average January temperature is about 25 degrees F. and the average July temperature is about 69 degrees F. The mean annual temperature is 46 to 50 degrees F. The frost-free season is 130 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ackna, Kayak Metser, Millhouse, Reelow, Reeser, Sketter and Weirman soils. Ackna soils are on terraces and alluvial fans, have less than 15 percent rock fragments in the upper part of argillic horizon and have 25 to 30 percent clay in particle-size control section. Kayak soils are on flood plains, have less than 18 percent clay in the particle-size control section and are 20 to 40 inches to a 2BC horizon. Metser soils are on terraces and alluvial fans, have 40 to 55 percent clay and 15 to 35 percent rock fragments in the particle-size control section. Millhouse soils on alluvial fans and terraces, have 20 to 25 percent clay in the particle-size control section and are 20 to 40 inches to a 2C horizon. Reelow, Reeser, Lablue and Sketter soils are on old fan remnants, old terraces and old till plains and all have a duripan. Weirman soils are on flood plains and low terraces and are sandy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained, slow runoff; slow permeability.
USE AND VEGETATION: These soils are used for livestock grazing, limited crop production, and wildlife habitat. Native vegetation is bluebunch wheatgrass, Sandberg bluegrass, Wyoming sagebrush and bitterbrush. When irrigated, hay, oats and wheat are among the crops grown.
DISTRIBUTION AND EXTENT: Kittitas County, Washington; MLRA 8. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Kittitas County, Washington, l999. Name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Mollic epipedon (pachic) - 0 to 48 inches or more (A, AB and Bt horizons)
Argillic horizon - 13 to 48 inches (Bt horizon)
PSCS - the zone from 13 to 33 inches (part of Bt horizon)
Vitrandic feature - 0 to 10 inches (Ap and A horizons).
Xeric soil moisture regime.