124 Classification of the Soils – Steiger Series

Classification of the Soils
 Steiger Series

 Depth class: Very deep

Drainage class: Somewhat excessively drained

Permeability: Rapid

Position on landscape: Pumice- and ash-mantled lava plains and ridges

Parent material: Ash and pumice

Slope range: 2 to 25 percent

Elevation: 4,500 to 6,000 feet

Average annual precipitation: 20 to 50 inches

Average annual air temperature: 38 to 42 degrees F

Frost-free period: 10 to 50 days

 Taxonomic class: Ashy, glassy Xeric Vitricryands

 Typical Pedon

 A—0 to 4 inches; very dark brown (10YR 2/2) ashy loamy coarse sand, dark grayish brown (10YR 4/2) dry; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine pores; about 10 percent paragravel pumice fragments; moderately acid (pH 5.6); abrupt wavy boundary.

Bw1—4 to 10 inches; dark brown (10YR 3/3) paragravelly ashy loamy coarse sand, pale brown (10YR 6/3) dry; single grain; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine pores; very slightly compacted; about 20 percent yellowish brown paragravel pumice fragments; slightly acid (pH 6.2); clear wavy boundary.

Bw2—10 to 19 inches; dark yellowish brown (10YR 4/4) paragravelly ashy loamy coarse sand, pale brown (10YR 6/3) dry; single grain; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; many very fine pores; very slightly compacted; about 20 percent yellowish brown paragravel pumice fragments; neutral (pH 6.7); gradual wavy boundary.

BC—19 to 29 inches; yellowish brown (10YR 5/4) paragravelly ashy coarse sand, light yellowish brown (10YR 6/4) dry; single grain; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; many very fine pores; about 30 percent yellowish brown paragravel pumice fragments; pocket of dark yellowish brown Bw material extends from the upper boundary through the lower boundary; slightly acid (pH 6.4); clear wavy boundary.

C1—29 to 35 inches; yellowish red (5YR 5/6) paragravelly ashy coarse sand, light reddish brown (5YR 6/4) dry; single grain; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; many very fine pores; about 20 percent paragravel pumice fragments; slightly acid (pH 6.5); gradual wavy boundary.

C2—35 to 60 inches; yellowish red (5YR 4/6) paragravelly ashy coarse sand, light reddish brown (5YR 6/3) dry; single grain; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; many very fine pores; about 20 percent paragravel pumice fragments; neutral (pH 6.8).

 Typical Pedon Location

 Map unit in which located: Lapine-Steiger-Wuksi complex, high elevation, 2 to 25 percent slopes Location: Outside park about 11/2 miles west and 3 miles south of the northwest corner of the park, in Klamath County, Oregon; 2,400 feet north and 2,600 feet east of the southwest corner of sec. 14, T. 33 S., R. 71/2 E.

 Range in Characteristics

 Profile:

Depth to bedrock—more than 60 inches

Content of pumice paragravel—5 to 35 percent

Field estimated content of clay—0 to 5 percent

Some pedons have an O horizon that is as much as 3 inches thick.

A horizon:

Value—2 or 3 moist, 4 or 5 dry

Chroma—2 moist, 1 or 2 dry

Content of paragravel—0 to 15 percent

Bw horizon:

Hue—10YR to 5YR

Value—3 to 5 moist, 4 to 6 dry

Chroma—2 to 4 moist or dry

Chroma of pumice fragments—4 to 8

Texture—ashy loamy coarse sand or ashy coarse sand

Content of pumice paragravel—5 to 35 percent

BC and C horizons:

Value—3 to 6 moist, 6 or 7 dry

Chroma—4 to 8 moist, 2 to 6 dry

Texture—ashy loamy coarse sand or ashy coarse sand

Content of pumice paragravel—15 to 60 percent

Pumice fragments commonly have the higher chroma and value.

 

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