123 Classification of the Soils – Redcone Series

Classification of the Soils
Redcone Series

 Depth class: Moderately deep to a duripan

Drainage class: Somewhat excessively drained

Permeability: Rapid to the cemented duripan and moderate through it

Position on landscape: Cinder cones

Parent material: Colluvium derived from ash and cinders

Slope range: 30 to 60 percent

Elevation: 5,500 to 7,500 feet

Average annual precipitation: 50 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 Duricryands

 Typical Pedon

 Oi—0 to 1 inch; slightly decomposed needle litter; 15 percent cinder gravel, 5 percent cinder cobbles, and 3 percent cinder stones; abrupt smooth boundary.

A—1 inch to 7 inches; dark brown (7.5YR 3/2) very gravelly ashy sandy loam, brown (7.5YR 5/2) dry; weak very fine granular structure; loose, very friable, nonsticky and nonplastic; many fine and medium roots and common very fine and coarse roots; many fine interstitial pores; 30 percent cinder gravel and 5 percent andesitic gravel; moderately acid (pH 5.8); clear wavy boundary.

Bw1—7 to 24 inches; dark brown (7.5YR 3/4) very gravelly ashy coarse sandy loam, brown (7.5YR 5/4) dry; weak fine subangular blocky structure parting to single grain; soft, very friable, nonsticky and nonplastic; common very fine, fine, medium, and coarse roots and few very coarse roots; many fine interstitial pores; 30 percent cinder gravel and 5 percent andesitic gravel; moderately acid (pH 5.8); clear wavy boundary.

Bw2—24 to 27 inches; dark brown (7.5YR 3/4) very gravelly ashy loamy sand, brown (7.5YR 5/4) dry; weak very fine and fine subangular blocky structure parting to single grain; loose, nonsticky and nonplastic; many fine interstitial pores; 55 percent cinder gravel; moderately acid (pH 6.0); abrupt wavy boundary.

2Bqsm—27 to 38 inches; dark red (2.5YR 3/6) weakly cemented gravelly ashy loamy sand, strong brown (7.5YR 5/8) dry; massive; hard, firm, nonsticky and nonplastic; few fine and medium interstitial pores; 20 percent black (7.5YR 2/1) cinder gravel; moderately acid (pH 6.0) clear wavy boundary.

2BC—38 to 61 inches; red (2.5YR 4/8), dark red (2.5YR 3/6), and dark reddish brown (2.5YR 3/4) extremely gravelly ashy loamy sand; massive; slightly hard, friable, nonsticky and nonplastic; few fine and medium interstitial pores; 80 percent black (7.5YR 2/1) cinder gravel; slightly acid (pH 6.2).

 Typical Pedon Location

 Map unit in which located: Redcone-Rock outcrop complex, 30 to 60 percent north slopes Location in park: About 1.5 miles west and 500 feet north of Red Cone Springs Trailhead in Crater Lake National Park; 568360 meters easting and 4761328 meters northing, UTM Zone 10T, NAD 27

 Range in Characteristics

 Profile:

Depth to bedrock—more than 60 inches

Depth to weakly cemented duripan—20 to 40 inches

A horizon:

Hue—7.5YR or 10YR

Value—2 or 3 moist, 4 or 5 dry

Chroma—2 to 4 moist or dry

Content of andesite gravel—0 to 10 percent

Content of cinder gravel—10 to 30 percent

Content of cinder cobbles—0 to 5 percent

Bw horizon:

Hue—7.5YR or 10YR

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

Content of andesite gravel—0 to 5 percent

Content of cinder gravel—25 to 55 percent

Content of cinder cobbles—0 to 5 percent

2Bqsm horizon:

Hue—2.5YR, 5YR, or 7.5YR

Value—2.5 to 5 moist or dry

Chroma—0, 1, 4, 6, or 8 moist or dry

Texture—ashy loamy sand or ashy sand

Content of cinder gravel—15 to 35 percent

Cementation—weakly cemented or moderately cemented

2BC horizon:

Hue—2.5YR, 5YR, or 7.5YR

Value—2.5 to 5 moist or dry

Chroma—0, 1, 4, 6, or 8 moist or dry

Texture—ashy loamy sand or ashy sand

Content of cinders—65 to 90 percent

 

<< previousnext >>