LOCATION DIAMONDPEAK CAEstablished Series
The Diamondpeak series consists of very deep, well drained soils that formed in tephra and colluvium over residuum from hydrothermally altered rocks. Diamondpeak soils are on mountain side slopes in hydrothermally altered areas in the Southern Cascade mountains. Slopes range from 10 to 80 percent. The mean annual precipitation is about 117 inches (2972 mm) and the mean annual temperature is about 39 degrees F (4 degrees C).
TAXONOMIC CLASS: Fine-loamy, isotic, frigid Typic Dystroxerepts
TYPICAL PEDON: Diamondpeak ashy loam, on a south facing (180 degrees) slope of 33 percent, under a cover of California red fir and lupine at an elevation of 7727 feet, (2356 m). When described on 9/20/06, the soil was dry throughout. (Colors are for dry soil unless otherwise noted).
Oi--0 to 1 inches (0 to 3 cm); needle and twig litter; abrupt smooth boundary. (0 to 1 inches, (0 to 3 cm) thick)
A--1 to 3 inches (3 to 7 cm); grayish brown (10YR 5/2) ashy loam, very dark grayish brown (10YR 3/2) moist; 25 percent clay; moderate very thick platy structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine and fine and few medium and coarse roots; common very fine interstitial and few fine and medium tubular pores; 3 percent subangular very strongly cemented fine gravel and 1 percent subangular very strongly cemented medium gravel; very strongly acid, pH 4.7 by pH meter 1:1 water; NaF pH 8.3; abrupt smooth boundary. (1 to 4 inches, (3.5 to 7 cm) thick)
2Bwb1--3 to 10 inches (7 to 26 cm); very pale brown (10YR 8/4) very paragravelly clay loam, brownish yellow (10YR 6/6) moist; 39 percent clay; moderate very fine and fine subangular blocky structure; slightly hard, friable, moderately sticky, moderately plastic; common very fine and few fine and medium roots; many very fine and fine irregular and common fine tubular pores; 30 percent subangular weakly cemented fine paragravel and 20 percent subangular weakly cemented medium paragravel; very strongly acid, pH 5.0 by pH meter 1:1 water; NaF pH 9.3; abrupt smooth boundary.
2Bwb2--10 to 31 inches (26 to 79 cm); 50 percent very pale brown (10YR 8/3) and 50 percent reddish yellow (7.5YR 8/6) very paragravelly sandy clay loam, reddish yellow (7.5YR 6/8) and yellow (10YR 7/6) moist; 27 percent clay; moderate fine to coarse subangular blocky structure; slightly hard, friable, moderately sticky, moderately plastic; few fine to very coarse roots; many very fine and fine irregular and common fine and medium tubular pores; 25 percent subangular weakly cemented fine paragravel and 30 percent subangular weakly cemented medium paragravel; strongly acid, pH 5.1 by pH meter 1:1 water; NaF pH 9.4; abrupt irregular boundary.
2Bwb3--31 to 49 inches (79 to 125 cm); 30 percent yellow (10YR 8/6) and 70 percent yellow (10YR 7/6) extremely paragravelly loam, brownish yellow (10YR 6/6) and yellow (10YR 7/6) moist; 21 percent clay; moderate fine and medium subangular blocky structure; slightly hard, friable, moderately sticky, moderately plastic; few fine and common medium roots; common very fine and fine irregular and common fine tubular pores; 30 percent angular very weakly cemented fine paragravel and 40 percent angular very weakly cemented medium paragravel; very strongly acid, pH 5.0 by pH meter 1:1 water; NaF pH 9.6; abrupt smooth boundary. (Combined thickness of the 2Bwb horizon is 37 to 47 inches, (94 to 119 cm) thick)
2Cr/2Bwb4--49 to 60 inches (125 to 152 cm); reddish yellow (7.5YR 6/8) extremely paragravelly loam, strong brown (7.5YR 5/8) moist; 18 percent clay; massive and moderate fine and medium subangular blocky structure; moderately hard, firm, moderately sticky, slightly plastic; few fine to very coarse roots; few fine tubular and common very fine and fine irregular pores; 30 percent angular very weakly cemented fine paragravel and 45 percent angular very weakly cemented medium paragravel; strongly acid, pH 5.1 by pH meter 1:1 water; NaF pH 9.6
TYPE LOCATION: Shasta County, California, about 0.7 miles north-northwest of Diamond Peak, approximately 1700 feet east and 1600 feet north of the southwest corner of sec 15, T. 30 N, R. 4 E, 40 degrees, 27 minutes, 28 seconds north latitude and 121 degrees, 31 minutes, 41 seconds west longitude, NAD83; USGS Quad: Lassen Peak, California.
RANGE IN CHARACTERISTICS:
Depth to restrictive feature: Paralithic contact greater than 60 inches (152 cm)
Mean annual soil temperature: 42 to 47 degrees F (6 to 8 degrees C).
Soil moisture control section is dry: July to October (about 90 days).
Particle-size control section (thickest part): 25 to 35 percent clay.
Surface fragments: 10 to 20 percent gravel, 0 to 5 percent cobbles, and 0 to 2 percent stones.
Some pedons have a Bw horizon above the 2Bwb horizon.
A horizon:
Color dry: 10YR 4/2, 4/3, 5/2, 5/3
Color moist: 10YR 3/2, 3/3
Texture: ashy loam, gravelly ashy loam
Clay content: 18 to 27 percent
Rock fragments: 3 to 12 percent fine gravel, 1 to 12 percent medium and coarse gravel, 4 to 24 percent total gravel
Organic matter: 14 to 18 percent
Base saturation by ammonium acetate: 35 to 45 percent
Acid oxalate extractable Al plus 1/2 Fe: 0.55 to 0.62
P retention: 48 to 55 percent
Glass content: 5 to 10 percent
NaF pH: 8.2 to 8.5
Soil reaction: very strongly acid to moderately acid
Upper 2Bwb horizon:
Color dry: variegated 10YR 5/8, 6/6, 7/2, 7/6, 8/1, 8/4, 8/8, 7.5YR 6/8
Color moist: variegated 10YR 5/4, 6/6, 8/3, 7.5YR 6/8, 7/3, 7/8, 8/3, 8/6
Texture: very paragravelly clay loam, paragravelly clay loam, very paragravelly sandy clay loam
Clay content: 25 to 40 percent
Rock fragments: 9 to 30 percent fine paragravel, 10 to 30 percent medium and coarse paragravel, 25 to 55 percent total paragravel, 0 to 10 percent paracobbles
Organic matter: 0.9 to 2.3 percent
Base saturation by ammonium acetate: 16 to 35 percent
Acid oxalate extractable Al plus 1/2 Fe: 0.58 to 0.82
P retention: 65 to 80 percent
Glass content: 0 to 1 percent
NaF pH: 9.1 to 10.0
Soil reaction: very strongly acid to moderately acid
Lower 2Bwb horizon:
Color dry: variegated 10YR 6/6, 7/6, 8/2, 7.5YR 5/8, 6/8, 7/3
Color moist: variegated 10YR 5/8, 7/6, 8/3, 8/6, 7.5YR 5/8, 6/8
Texture: very paragravelly loam, extremely paragravelly loam
Clay content: 18 to 25 percent
Rock fragments: 15 to 30 percent fine paragravel, 20 to 50 medium and coarse paragravel, 45 to 75 percent total paragravel, 0 to 5 percent paracobbles
Organic matter: 0.5 to 1.2 percent
Base saturation by ammonium acetate: 8 to 15 percent
Acid oxalate extractable Al plus 1/2 Fe: 0.95 to 1.10
P retention: 90 to 95 percent
Glass content: 0 to 1 percent
NaF pH: 9.1 to 9.6
Soil reaction: extremely acid to strongly acid
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Diamondpeak soils are on mountain side slopes in hydrothermally altered areas in the Southern Cascade mountains. Slopes are 10 to 80 percent. These soils formed in tephra and colluvium over residuum weathered from hydrothermally altered rocks. Elevation is 5674 to 7900 feet (1730 to 2407 m). Mean annual precipitation is 63 to 119 inches (1600 to 3023 mm). The mean annual temperature is 39 to 40 degrees F (4 to 5 degrees C). Frost free season is 60 to 85 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Brokeoff soil. The Brokeoff soils are moderately deep to lithic bedrock and occur on convex slopes in hydrothermally altered areas.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: well drained; saturated hydraulic conductivity is moderately high to high in the A horizon, and moderately low to high in the 2Bwb horizons.
USE AND VEGETATION: This soil is used for wildlife habitat, recreation, ecosystem management and watershed. Vegetation is California red fir, mountain hemlock, western white pine, lupine, western needlegrass, mountain monardella and squirreltail.
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: 2009 Shasta County, California. Source of name from Diamond Peak in Lassen Volcanic National Park.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 1 to 3 inches, (3 to 7 cm)
Cambic horizon: 3 to 49 inches, (7 to 125 cm)
Particle-size control section: 11 to 41 inches, (28 to 103 cm)
Soil moisture control section: 11 to 39 inches, (28 to 99 cm)
ADDITIONAL DATA:
Characterization data from lab pedon number 07N0140, NSSL, Lincoln, NE. NASIS User Pedon ID in Davis, MLRA Office: 789210.