130 Classification of the Soils – Wuksi Series

Classification of the Soils
 Wuksi Series

Depth class: Very deep

Drainage class: Somewhat excessively drained

Permeability: Rapid

Position on landscape: Lava flows and volcanic buttes

Parent material: Ash mixed with colluvium derived from andesite

Slope range: 2 to 70 percent

Elevation: 4,500 to 6,500 feet

Average annual precipitation: 25 to 40 inches

Average annual air temperature: 38 to 42 degrees F

Frost-free period: 10 to 50 days

 Taxonomic class: Ashy-skeletal, glassy Xeric Vitricryands

 Typical Pedon

  Oi—0 to 1 inch; slightly decomposed needles; abrupt smooth boundary.

A—1 inch to 5 inches; dark yellowish brown (10YR 3/4) cobbly ashy loamy sand, dark yellowish brown (10YR 4/4) dry; weak fine granular structure; loose, nonsticky and nonplastic; many very fine, fine, and medium roots; many very fine irregular pores; 15 percent andesite gravel and 15 percent andesite cobbles; strongly acid (pH 5.4); clear wavy boundary.

 AB—5 to 14 inches; brown (7.5YR 4/4) very cobbly ashy loamy coarse sand, strong brown (7.5YR 4/6) dry; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots and common medium and coarse roots; many fine irregular pores; 15 percent andesite gravel, 30 percent andesite cobbles, and 5 percent andesite stones; moderately acid (pH 6.0); clear wavy boundary.

Bw1—14 to 29 inches; dark brown (7.5YR 3/4) very cobbly ashy loamy sand, strong brown (10YR 4/6) dry; weak very fine subangular blocky structure; soft, very friable , nonsticky and nonplastic; many very fine and fine roots and common medium roots; many fine and medium irregular pores; 15 percent andesite gravel, 35 percent andesite  cobbles, and 5 percent stones; moderately acid (pH 6.0); clear wavy boundary.

Bw2—29 to 37 inches; brown (7.5YR 4/3) very cobbly ashy sandy loam, yellowish brown (10YR 5/6) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and medium roots; many fine and medium irregular pores; 15 percent andesite gravel, 35 percent andesite cobbles, and 5 percent andesite stones; moderately acid (pH 6.0); clear irregular boundary.

Bw3—37 to 60 inches; brown (7.5YR 4/3) extremely cobbly ashy sandy loam, yellowish brown (7.5YR 5/6) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many fine irregular pores; 15 percent andesite gravel, 55 percent andesite cobbles, and 5 percent andesite stones; moderately acid (pH 6.0).

 Typical Pedon Location

 Map unit in which located: Lapine-Steiger-Wuksi complex, high elevation, 2 to 25 percent slopes

Location in park: Northeastern side of Crater Lake National Park, in the Sharp Peak area and on the eastern flank of Timber Crater; 580696 meters easting and 4766251 meters northing, UTM Zone 10T, NAD 27

 Range in Characteristics

 Profile:

Depth to bedrock—more than 60 inches

Content of clay—0 to 5 percent

A and AB horizons (where present):

Hue—10YR or 7.5YR

Value—3 or 4 moist, 4 to 6 dry

Chroma—2 to 4 moist or dry

Texture—cobbly ashy loamy sand, cobbly ashy loamy coarse sand, very cobbly ashy loamy sand, and very cobbly ashy loamy coarse sand

Content of gravel—10 to 30 percent

Content of cobbles—15 to 45 percent

Content of stones—0 to 5 percent

Bw horizon and C horizon (where present):

Hue—10YR or 7.5YR

Value—3 to 5 moist, 4 to 6 dry

Chroma—3 to 6 moist or dry

Content of gravel—15 to 25 percent

Content of cobbles—25 to 60 percent

Content of stones—0 to 5 percent

 

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