LOCATION PROSPECTPEAK CAEstablished Series
TAXONOMIC CLASS: Fragmental, isotic, frigid Typic Vitrixerands
TYPICAL PEDON: Prospectpeak, ashy coarse sand, on an east facing (73 degrees) slope of 10 percent, under a cover of California red fir, Jeffrey pine, white fir, pinemat manzanita, bush chinquapin, whiteveined wintergreen, mountain monardella and western needlegrass at an elevation of 7057 feet, (2152 m). When described on 7/6/06, the soil was dry to 14 inches, (35 cm) and slightly moist from 14 to 50 inches, (35 to 127 cm). (Colors are for dry soil unless otherwise noted).
Oi--0 to 1 inches (0 to 3 cm); slightly decomposed cones, needle and twig litter; abrupt smooth boundary.
A--1 to 3 inches (2 to 7 cm); very dark gray (2.5Y 3/1) ashy coarse sand, black (2.5Y 2.5/1) moist; 0 percent clay; single grain; loose, nonsticky, nonplastic; many very fine roots; common very fine and fine interstitial pores; 10 percent angular fine gravel and 3 percent angular medium and coarse gravel; slightly acid, pH 6.4 by pH meter 1:1 water; NaF pH 9.1; abrupt smooth boundary. (2 to 5 inches (5 to 13 cm) thick)
C1--3 to 7 inches (7 to 17 cm); very dark gray (2.5Y 3/1) gravelly ashy coarse sand, black (2.5Y 2.5/1) moist; 0 percent clay; single grain; loose, nonsticky, nonplastic; common very fine and fine and few medium roots; common very fine and fine interstitial pores; 12 percent angular fine gravel and 3 percent angular medium and coarse gravel; neutral, pH 6.6 by pH meter 1:1 water; NaF pH 9.0; abrupt wavy boundary.
C2--7 to 9 inches (17 to 22 cm); grayish brown (2.5Y 5/2) extremely gravelly ashy coarse sand, very dark grayish brown (2.5Y 3/2) moist; 0 percent clay; single grain; loose, nonsticky, nonplastic; many very fine and fine and few medium roots; few very fine and fine interstitial and many medium interstitial pores; 35 percent angular fine gravel, 25 percent angular medium and coarse gravel and 5 percent subangular cobbles; neutral, pH 6.8 by pH meter 1:1 water; NaF pH 9.3; clear smooth boundary. (Combined thickness of the C horizon is 5 to 8 inches (13 to 20 cm) thick)
2Ab--9 to 14 inches (22 to 35 cm); very pale brown (10YR 7/3) extremely stony ashy coarse sand, brown (10YR 4/3) moist; 0 percent clay; single grain; loose, nonsticky, nonplastic; common very fine and medium, many fine and few coarse roots; common very fine to medium interstitial pores; 7 percent subangular fine gravel, 5 percent subangular medium and coarse gravel, 35 percent subangular cobbles, 30 percent angular stones and 12 percent angular boulders; neutral, pH 6.9 by pH meter 1:1 water; NaF pH 9.7; abrupt smooth boundary. (4 to 7 inches (10 to 18 cm) thick)
2Bwb1--14 to 22 inches (35 to 55 cm); pale brown (10YR 6/3) extremely stony ashy coarse sandy loam, dark yellowish brown (10YR 4/4) moist; 4 percent clay; single grain; loose, nonsticky, nonplastic; many very fine, common fine and medium and few coarse roots; common very fine and fine irregular pores; 5 percent subangular fine gravel, 5 percent subangular medium and coarse gravel, 35 percent subangular cobbles, 30 percent angular stones and 12 percent angular boulders; neutral, pH 6.6 by pH meter 1:1 water; NaF pH 10.1; abrupt smooth boundary.
2Bwb2--22 to 50 inches (55 to 127 cm); light yellowish brown (10YR 6/4) medial stones, dark yellowish brown (10YR 3/4) moist; 4 percent clay; weak very fine and fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; few very fine and common fine to coarse roots; 5 percent subangular fine gravel, 10 percent subangular medium and coarse gravel, 35 percent subangular cobbles, 30 percent angular stones and 12 percent angular boulders; neutral, pH 6.7 by pH meter 1:1 water; NaF pH 10.6; abrupt smooth boundary. (Combined thickness of the 2Bw horizon is 34 to 38 inches (86 to 97 cm) thick)
2R--50 to 66 inches (127 to 167 cm); indurated vesicular andesite
TYPE LOCATION: Shasta County, California, about 1 mile north-northwest of Cinder Cone, approximately 2300 feet south and 850 feet west of the northeast corner of sec 8, T. 31 N, R. 6 E, 40 degrees, 33 minutes, 51 seconds north latitude and 121 degrees, 19 minutes, 34 seconds west longitude, NAD83; USGS Quad: Prospect Peak, California.
RANGE IN CHARACTERISTICS:
Depth to restrictive feature: Lithic contact 40 to 60 inches (102 to 152 cm)
Mean annual soil temperature: 45 to 47 degrees F (7 to 8 degrees C)
Soil moisture control section is dry: July to October (about 90 days)
Particle-size control section (thickest part): 4 percent clay, and 92 percent rock fragments
Surface fragments: 3 to 8 percent gravel, 0 to 8 percent cobbles, 3 to 15 percent stones, and 2 to 20 percent boulders
A horizon:
Color dry: 10YR 3/1, 4/1, 2.5Y 2.5/1, 3/1, 4/1, 4/2, 5Y 2/1, 2.5/1, 3/2
Color moist: 10YR 2/1, 3/1, 2.5Y 2.5/1, 3/1, 5Y 2/1, 2.5/1
Texture: ashy sand, gravelly ashy sand, ashy loamy sand, ashy sandy loam, ashy coarse sand
Clay content: 0 to 2 percent
Rock fragments: 5 to 18 percent fine gravel, 3 to 8 percent medium and coarse gravel, 8 to 22 percent total gravel, 0 to 5 percent cobbles, 0 to 5 percent stones, 8 to 30 percent total rock fragments
Organic matter: 0.5 to 3.5 percent
Base saturation by ammonium acetate: 70 to 95 percent
Acid oxalate extractable Al plus 1/2 Fe: 0.05 to 0.15
P retention: 2 to 6 percent
Glass content: 40 to 50 percent
NaF pH: 9.0 to 9.4
Soil reaction: moderately acid to neutral
C horizon:
Color dry: N 3/, 4/, 5/, 10YR 3/1, 3/2, 4/1, 4/2, 4/4, 6/6, 7/2, 7/4, 2.5Y 3/1, 4/1, 4/2, 5/1, 5/2, 5/3, 5Y 2/1, 2.5/1, 3/1, 4/1, 5/2
Color moist: N 2.5/, 3/, 5B 4/1, 5/1, 6/1, 7.5YR 2.5/1, 10YR 2/1, 3/1, 3/4, 4/1, 4/2, 4/3, 5/6, 2.5Y 2.5/1, 3/1, 3/2, 4/2, 5Y 2/1, 2.5/1, 2.5/2, 4/3
Texture: gravelly sand, gravelly coarse sand, extremely gravelly ashy coarse sand, extremely gravelly ashy very coarse sand
Clay content: 0 to 1 percent
Rock fragments: 10 to 38 percent fine gravel, 2 to 28 percent medium and coarse gravel, 12 to 60 percent total gravel, 0 to 15 percent cobbles, 0 to 25 percent stones, 15 to 85 percent total rock fragments
Organic matter: 0 to 0.8 percent
Base saturation by ammonium acetate: 58 to 75 percent
Acid oxalate extractable Al plus 1/2 Fe: 0.05 to 0.25
P retention: 3 to 8 percent
Glass content: 3 to 8 percent
NaF pH: 9.7 to 10.2
Soil reaction: slightly acid or neutral
2Ab horizon:
Color dry: 10YR 6/3, 7/2, 7/3
Color moist: 10YR 4/2, 4/3
Texture: extremely stony ashy sand, extremely stony ashy coarse sand, extremely cobbly ashy coarse sand, extremely cobbly ashy loamy coarse sand
Clay content: 0 to 2 percent
Rock fragments: 3 to 10 percent fine gravel, 3 to 10 percent medium and coarse gravel, 8 to 18 percent total gravel, 10 to 35 percent cobbles, 10 to 30 percent stones, 5 to 15 percent boulders, 60 to 89 percent total rock fragments
Organic matter: 0.7 to 1.5 percent
Base saturation by ammonium acetate: 43 to 58 percent
Acid oxalate extractable Al plus 1/2 Fe: 0.30 to 0.85
P retention: 20 to 30 percent
Glass content: 25 to 31 percent
NaF pH: 9.8 to 10.1
Soil reaction: slightly acid or neutral
Upper 2Bwb horizon:
Color dry: 10YR 5/4, 6/3, 6/4
Color moist: 10YR 4/3, 4/4
Texture: extremely cobbly ashy loamy sand, extremely stony ashy loamy sand, extremely stony ashy sandy loam, extremely stony ashy coarse sandy loam
Clay content: 1 to 5 percent
Rock fragments: 5 to 15 percent fine gravel, 5 to 30 percent medium and coarse gravel, 10 to 40 percent total gravel, 18 to 40 percent cobbles, 15 to 30 percent stones, 0 to 15 percent boulders, 60 to 89 percent total rock fragments
Organic matter: 1.2 to 2.0 percent
Base saturation by ammonium acetate: 23 to 38 percent
Acid oxalate extractable Al plus 1/2 Fe: 2.25 to 3.75
P retention: 70 to 95 percent
Glass content: 30 to 40 percent
NaF pH: 10.0 to 10.3
Soil reaction: slightly acid or neutral
Lower 2Bwb horizon:
Color dry: 10YR 5/3, 6/3, 6/4
Color moist: 10YR 3/4, 4/3, 4/4
Texture: extremely gravelly medial sandy loam, extremely gravelly medial loamy sand, extremely cobbly medial loamy coarse sand, extremely cobbly medial coarse sandy loam, medial stones
Clay content: 2 to 8 percent
Rock fragments: 5 to 15 percent fine gravel, 8 to 50 percent medium and coarse gravel, 15 to 60 percent total gravel, 15 to 35 percent cobbles, 0 to 30 percent stones, 0 to 15 percent boulders, 60 to 95 percent total rock fragments
Organic matter: 0.7 to 1.5 percent
Base saturation by ammonium acetate: 23 to 38 percent
Acid oxalate extractable Al plus 1/2 Fe: 2.25 to 3.75
P retention: 70 to 95 percent
Glass content: 5 to 18 percent
NaF pH: 10.3 to 10.6
Soil reaction: slightly acid or neutral
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Prospectpeak soils are on shield volcanoes in the Southern Cascade mountains. Slopes are 10 to 30 percent. These soils formed in tephra from Cinder Cone over tephra from Chaos Crags mixed with residuum from andesite. Elevation is 6445 to 7990 feet (1965 to 2436 m). Mean annual precipitation is 31 to 43 inches (787 to 1092 mm). The mean annual temperature is 43 degrees F (6 degrees C). Frost free season is 50 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bearrubble, Buttelake and Badgerflat soils. The Bearrubble soils are very deep and have more stones and boulders at the surface and in the upper profile due to a thinner mantle of tephra on the surface. The Buttelake soils are deep to dense till and are on moraines that are covered with a mantle of tephra from Cinder Cone. The Badgerflat soils are moderately deep to dense till and are on moraines with a mantle of tephra from Chaos Crags.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; saturated hydraulic conductivity is high to very high in the A horizon, very high in the C and 2Ab horizons, high in the upper 2Bwb horizon and high to very high in the lower 2Bwb horizon.
USE AND VEGETATION: This soil is used for wildlife habitat, recreation, ecosystem management and watershed. Vegetation is California red fir, Jeffrey pine, pinemat manzanita and bush chinquapin.
DISTRIBUTION AND EXTENT: The soils are inextensive and are mapped in MLRA: 22B Southern Cascade mountains
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Shasta County, California. Source of name from Prospect Peak in Lassen Volcanic national Park.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 9 to 14 inches, (22 to 35 cm)
Cambic horizon: 14 to 22 inches, (35 to 55 cm)
Andic soil properties: 14 to 50 inches, (35 to 127 cm)
Particle-size control section: 1 to 41 inches, (2 to 104 cm)
Lithic contact: 50 inches, (127 cm)
Soil moisture control section: 27 to 50 inches, (69 to 127 cm)
ADDITIONAL DATA:
Characterization data from lab pedon number 07N0138 NSSL, Lincoln, NE. NASIS User Pedon ID in Davis MLRA Office: S06CA089001.