126 Classification of the Soils – Sunnotch Series

Classification of the Soils
Sunnotch Series

Depth class: Very deep

Drainage class: Somewhat excessively drained

Permeability: Rapid

Position on landscape: Debris flows on mountains

Parent material: Ash and cinders

Slope range: 0 to 45 percent

Elevation: 5,000 to 8,000 feet

Average annual precipitation: 40 to 70 inches

Average annual air temperature: 38 to 42 degrees F

Frost-free period: 0 to 50 days

 Taxonomic class: Ashy-skeletal, amorphic Typic Vitricryands

 Typical Pedon

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

A1—1 inch to 3 inches; very dark brown (10YR 2/2) gravelly ashy sandy loam, very dark grayish brown (10YR 3/2) dry; weak fine and medium granular structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; many very fine interstitial pores; 10 percent black cinder gravel, 10 percent andesite gravel, and 10 percent pumice paragravel; moderately acid (pH 5.9); abrupt smooth boundary.

A2—3 to 11 inches; very dark grayish brown (10YR 3/2) ashy loamy sand, brown (10YR 5/3) dry; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, and medium roots and few coarse roots; many very fine interstitial pores; 5 percent black cinder gravel, 5 percent andesite gravel, and 5 percent pumice paragravel; slightly acid (pH 6.3); clear wavy boundary.

Bw—11 to 25 inches; dark brown (10YR 3/3) very gravelly ashy loamy sand, brown (10YR 5/3) dry; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots and common medium roots; many very fine interstitial pores; 20 percent black cinder gravel, 10 percent red cinder gravel, 10 percent andesite gravel, and 10 percent pumice paragravel; slightly acid (pH 6.4); clear smooth boundary.

2C—25 to 61 inches; dark brown (7.5YR 3/4) very gravelly ashy sand, brown (7.5YR 5/4) dry; single grain; soft, very friable, nonsticky and nonplastic; few fine roots; many very fine interstitial pores; 20 percent black cinder gravel, 10 percent black cinder cobbles, 15 percent andesite gravel, 15 percent pumice paragravel, and 3 percent pumice paracobbles; slightly acid (pH 6.4)

 Typical Pedon Location

 Map unit in which located: Castlecrest gravelly ashy sandy loam, 2 to 10 percent slopes

Location in park: About 1 mile north of Red Cone Spring and about 350 feet west of Boundary Springs Trail; 565967 meters easting and 4762797 meters northing, UTM Zone 10T, NAD 27; lat. 43o1’0.37″, long. 122o11’29.83″

 Range in Characteristics

 Profile:

Depth to bedrock—more than 60 inches

Content of rock fragments—averages 35 to 50 percent

Content of pararock fragments—averages 5 to 20 percent

Some pedons may have stone- or boulder-sized cinders on the surface.

Cinders commonly are rounded or subrounded.

A horizon:

Hue—10YR or 7.5YR

Value—2 to 5 moist, 3 to 6 dry

Chroma—2 to 4 moist or dry

Texture—gravelly ashy sandy loam, gravelly ashy loamy sand, ashy sandy loam, and ashy loamy sand

Content of cinder gravel—5 to 20 percent

Content of andesite gravel—5 to 25 percent

Content of pumice paragravel—0 to 20 percent

Bw horizon:

Hue—10YR or 7.5YR

Value—3 or 4 moist, 4 to 6 dry

Chroma—2 to 6 moist or dry

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

Content of cinder gravel—5 to 35 percent

Content of andesite gravel—5 to 20 percent

Content of pumice paragravel—0 to 10 percent

Content of clay—0 to 7 percent

2C horizon:

Hue—10YR, 7.5YR, or 5YR

Value—3 or 4 moist, 5 or 6 dry

Chroma—3 to 6 moist or dry

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

Content of cinder gravel—15 to 40 percent

Content of cinder cobbles—0 to 15 percent

Content of cinders more than 10 inches in diameter—0 to 15 percent

Content of andesite gravel—15 to 60 percent

Content of pumice paragravel—0 to 10 percent

Content of pumice paracobbles—0 to 5 percent

Content of clay—0 to 5 percent

 

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