112 Classification of the Soils – Cleetwood Series

Classification of the Soils
 Cleetwood Series

Depth class: Very deep

Drainage class: Excessively drained

Permeability: Rapid

Position on landscape: Mountainsides, benches, and valleys

Parent material: Ash, and andesite and pumice fragments

Slope range: 0 to 30 percent

Elevation: 5,500 to 8,000 feet

Average annual precipitation: 40 to 80 inches

Average annual air temperature: 38 to 42 degrees F

Frost-free period: 0 to 30 days

 Taxonomic class: Ashy, glassy, nonacid Vitrandic Cryopsamments

 Typical Pedon

 A1—0 to 2 inches; very dark brown (10YR 2/2) very gravelly ashy loamy coarse sand, light brownish gray (10YR 6/2) dry; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine interstitial pores; 45 percent andesite and cinder gravel, 5 percent andesite and cinder cobbles, and 1 percent andesite stones; moderately acid (pH 6.0); clear wavy boundary.

A2—2 to 10 inches; very dark brown (10YR 2/2) ashy loamy sand, light brownish gray (10YR 6/2) dry; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots and few medium roots; many very fine interstitial pores; 10 percent andesite gravel; slightly acid (pH 6.2); clear wavy boundary.

C1—10 to 36 inches; dark brown (7.5YR 3/2) ashy sand, pinkish gray (7.5YR 6/2) dry; massive; slightly hard, firm, nonsticky and nonplastic; common very fine roots; many very fine interstitial pores; 5 percent andesite gravel; slightly acid (pH 6.2); abrupt wavy boundary.

C2—36 to 50 inches; dark reddish brown (5YR 3/3) ashy coarse sand, light reddish brown (5YR 6/4) dry; single grain; loose, nonsticky and nonplastic; many fine interstitial pores; 5 percent andesite gravel; slightly acid (pH 6.4); abrupt wavy boundary.

C3—50 to 60 inches; very dark grayish brown (10YR 3/2) gravelly ashy sand, light brownish gray (10YR 6/2) dry; single grain; loose, nonsticky and nonplastic; many fine interstitial pores; 15 percent andesite gravel; slightly acid (pH 6.4).

 Typical Pedon Location

 Map unit in which located: Cleetwood, thin surface-Cleetwood-Dyarock complex, 2 to 20 percent slopes

Location in park: Meadow about one-half mile north of Watchman Lookout and west of the caldera rim; 567553 meters easting and 4755091 meters northing, UTM Zone 10T, NAD 27; lat. 42o56’50.02″ N., long. 122o10’23.07″ W.

 Range in Characteristics

Profile:

Depth to bedrock—more than 60 inches

Thickness of solum—4 to 14 inches

Content of pumice—0 to 15 percent

Content of clay—0 to 5 percent

A1 horizon:

Hue—10YR or 7.5YR

Value—2 or 3 moist, 3 to 6 dry

Chroma—2 or 3 moist or dry

Texture—ashy loamy coarse sand, gravelly ashy loamy sand, gravelly ashy sandy loam, very gravelly ashy loamy sand, or very gravelly ashy loamy coarse sand

Content of rock fragments—0 to 55 percent

A2 horizon:

Hue—10YR or 7.5YR

Value—2 or 3 moist, 3 to 6 dry

Chroma—2 or 3 moist or dry

Texture—ashy loamy sand, ashy loamy coarse sand, or ashy sandy loam

Content of rock fragments—0 to 25 percent

C horizon:

Hue—10YR, 7.5YR, 5YR, or 2.5YR

Value—3 or 4 moist, 4 to 6 dry

Chroma—2 to 4 moist or dry

Texture—ashy sand, ashy loamy sand, ashy coarse sand, or ashy loamy coarse sand

Content of rock fragments—0 to 25 percent

Consistence when dry—loose to very firm

 

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