LOCATION SHADOWLAKE CAEstablished Series
The Shadowlake series consists of deep, well drained soils that formed in tephra over or mixed with till from volcanic rocks. Shadowlake soils are on ground moraines and glacial-valley walls in the Southern Cascade mountains. Slopes range from 2 to 80 percent. The mean annual precipitation is about 83 inches (2108 mm) and the mean annual temperature is about 41 degrees F (5 degrees C).
TAXONOMIC CLASS: Ashy-skeletal, glassy Xeric Vitricryands
TYPICAL PEDON: Shadowlake gravelly ashy sandy loam, on a northwest facing (315 degrees) slope of 2 percent, under a cover of California red fir and lodgepole pine at an elevation of 7486 feet, (2282 m). When described on 8/8/2007, the soil was dry throughout. (Colors are for dry soil unless otherwise noted).
Oi--0 to 1 inches (0 to 2 cm); slightly decomposed cones, needles and twig litter; abrupt smooth boundary.
A--1 to 2 inches (2 to 6 cm); grayish brown (10YR 5/2) gravelly ashy sandy loam, very dark grayish brown (10YR 3/2) moist; 5 percent clay; weak thin platy parting to weak fine granular structure parting to single grain; common very fine roots; common very fine irregular pores; 22 percent subangular fine gravel, 10 percent subangular medium and coarse gravel; moderately acid, pH 6.0 by Hellige-Truog; NaF pH 9.5; abrupt wavy boundary. (1 to 7 inches (4 to 18 cm) thick)
Bw1--2 to 6 inches (6 to 16 cm); light gray (10YR 7/2) gravelly ashy sandy loam, brown (10YR 5/3) moist; 5 percent clay; weak very fine and fine subangular blocky structure parting to single grain; common very fine and fine and few medium roots; many very fine tubular and interstitial pores; 18 percent subangular fine gravel and 10 percent subangular medium and coarse gravel; slightly acid, pH 6.5 by Hellige-Truog; NaF pH 11.5; clear smooth boundary.
Bw2--6 to 13 inches (16 to 32 cm); very pale brown (10YR 7/3) gravelly ashy sandy loam, brown (10YR 4/3) moist; 6 percent clay; weak very fine and fine subangular blocky structure parting to single grain; common very fine and fine, many medium, and few coarse and very coarse roots; common very fine tubular and irregular pores; 23 percent subangular fine gravel and 10 percent subangular medium and coarse gravel; slightly acid, pH 6.3 by Hellige-Truog; NaF pH 11.5; clear wavy boundary.
Bw3--13 to 23 inches (32 to 58 cm); very pale brown (10YR 7/3) very gravelly ashy sandy loam, brown (10YR 5/3) moist; 5 percent clay; weak fine and medium subangular blocky structure parting to single grain; common very fine and fine, many medium, and common coarse and very coarse roots; common very fine irregular and tubular pores; 20 percent subangular fine gravel, 20 percent subangular medium and coarse gravel, and 5 percent subangular cobbles; neutral, pH 6.7 by Hellige-Truog; NaF pH 11.5; abrupt smooth boundary. (Combined thickness of the Bw horizon is 18 to 33 inches (46 to 84 cm) thick)
Bq--23 to 41 inches (58 to 104 cm); white (10YR 8/1) extremely gravelly ashy coarse sandy loam, grayish brown (2.5Y 5/2) moist; 5 percent clay; massive; very hard, extremely firm; few very fine, common fine and medium, and few coarse and very coarse roots; many very fine irregular and tubular pores; 20 percent silica masses in pores and around rock fragments; 31 percent subangular fine gravel and 30 percent subangular medium and coarse gravel; neutral, pH 7.2 by Hellige-Truog; NaF pH 11.3; abrupt smooth boundary. (15 to 20 inches (38 to 51 cm) thick)
Cdq--41 inches (104 to cm); white (2.5Y 8/1) loam, light olive brown (2.5Y 5/3) moist; 12 percent clay; massive; extremely hard, slightly rigid, slightly sticky; few very fine to very coarse roots matted at top of horizon; common very fine irregular and tubular pores; 10 percent silica masses in pores and around rock fragments; 12 percent subangular fine gravel and 2 percent subangular medium and coarse gravel; slightly acid, pH 6.5 by Hellige-Truog; NaF pH 11.2
TYPE LOCATION: Shasta County, California, about 0.5 miles east of Shadow Lake, approximately 700 feet south and 200 feet east of the northwest corner of sec 8, T. 30 N, R. 5 E, 40 degrees, 28 minutes, 50 seconds north latitude and 121 degrees, 27 minutes, 30 seconds west longitude, NAD83; USGS Quad: Reading Peak, California.
RANGE IN CHARACTERISTICS:
Depth to restrictive feature: Densic contact 40 to 60 inches (102 to 152 cm).
Mean annual soil temperature: 40 to 43 degrees F (4 to 6 degrees C).
Soil moisture control section is dry: July to October (about 90 days).
Particle-size control section (thickest part): 5 percent clay, and 45 to 61 percent rock fragments.
Surface fragments: 7 to 40 percent gravel, 3 to 5 percent cobbles, 1 to 10 percent stones, and 0 to 10 percent boulders.
A horizon:
Color dry: 10YR 5/2, 5/3, 6/3
Color moist: 10YR 2/2, 3/2, 4/2
Texture: gravelly ashy sandy loam
Clay content: 1 to 6 percent
Rock fragments: 10 to 22 percent fine gravel, 8 to 12 percent medium and coarse gravel, 18 to 34 percent total gravel
Organic matter: 4 to 12 percent
Acid oxalate extractable Al plus 1/2 Fe: 0.52 to 0.71
P retention: 25 to 55
Glass content: 30 to 40 percent
NaF pH: 9.5 to 12
Soil reaction: moderately acid to neutral
Bw horizon:
Color dry: 10YR 6/3, 6/4, 7/2, 7/3, 7/4, 8/3
Color moist: 7.5YR 4/4, 10YR 3/3, 3/4, 4/3, 4/6, 5/3, 5/4
Texture: gravelly ashy sandy loam, very gravelly ashy sandy loam, very bouldery ashy sandy loam
Clay content: 3 to 8 percent
Rock fragments: 5 to 23 percent fine gravel, 6 to 20 percent medium and coarse gravel, 11 to 33 percent total gravel, 0 to 15 percent cobbles, 0 to 10 percent stones, 0 to 10 percent boulders, 28 to 59 percent total rock fragments
Organic matter: 3.5 to 8.6 percent
Acid oxalate extractable Al plus 1/2 Fe: 2.0 to 2.5
P retention: 65 to 90
Glass content: 36 to 45 percent
NaF pH: 11.0 to 11.5
Soil reaction: moderately acid to neutral
Bq horizon:
Color dry: 10YR 7/4, 8/1, 2.5Y 7/4, 8/1
Color moist: 2.5Y 5/2, 5/3, 6/2, 10YR 4/4
Texture: extremely gravelly ashy coarse sandy loam
Clay content: 1 to 5 percent
Rock fragments: 28 to 32 percent fine gravel, 28 to 32 percent medium and coarse gravel, 60 to 64 percent total gravel, 0 to 15 percent cobbles, 0 to 10 percent stones, 0 to 10 percent boulders, 60 to 75 percent total rock fragments
Organic matter: 0.5 to 1.5 percent
Acid oxalate extractable Al plus 1/2 Fe: 1 to 1.5
P retention: 45 to 55
Glass content: 15 to 30 percent
NaF pH: 11.2 to 11.4
Rupture resistance: noncemented
Soil reaction: neutral
Cdq horizon:
Color dry: 7.5YR 8/2, 2.5Y 8/1, 10YR 7/2
Color moist: 7.5YR 4/4, 2.5Y 5/3, 10YR 4/2
Texture: loam, extremely bouldery loamy coarse sand, very gravelly sandy loam
Clay content: 1 to 12 percent
Rock fragments: 9 to 12 percent fine gravel, 2 to 14 percent medium and coarse gravel, 14 to 78 percent total gravel, 0 to 15 percent cobbles, 0 to 20 percent stones, 0 to 20 percent boulders, 14 to 78 percent total rock fragments
Organic matter: 0 to 0.3 percent
Acid oxalate extractable Al plus 1/2 Fe: 0.5 to 0.7
P retention: 25 to 35
Glass content: 15 to 30 percent
NaF pH: 10.0 to 11.2
Rupture resistance: slightly hard to extremely hard
Soil reaction: moderately acid or slightly acid
COMPETING SERIES: COMPETING SERIES: These are the Azwell, Bamber, Fears, Gurlidawg, Hallihan, Madrak, Terence, Tiptop, Wuksi, Terracelake, Emeraldlake, and Readingpeak soils. Azwell, Gurlidawg, Madrak, and Terracelake soils are moderately deep to bedrock. Bamber and Readingpeak soils are deep to bedrock. Fears, Hallihan, Terence, Tiptop, Wuksi, and Emeraldlake soils are very deep.
GEOGRAPHIC SETTING: Shadowlake soils are on ground moraines and glacial-valley walls in the Southern Cascade mountains. Slopes are 2 to 80 percent. These soils formed in tephra over or mixed with till from volcanic rocks. Elevation is 5720 to 8512 feet (1744 to 2595 m). Mean annual precipitation is 55 to 117 inches (1397 to 2972 mm). The mean annual temperature is 38 to 43 degrees F (3.6 to 6 degrees C). Frost free season is 50 to 85 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Acroph and Terracelake soils. The Acroph soils are shallow to bedrock and are on scoured convex areas in glacial valleys. The Terracelake soils are moderately deep to bedrock and are on scoured linear and convex areas in glacial valleys.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; saturated hydraulic conductivity is high in the A and Bw horizons, high to very high in the Bq horizon, and moderately low in the Cdq horizon.
USE AND VEGETATION: This soil is used for wildlife habitat, recreation, ecosystem management, and watershed. Vegetation is California red fir, lodgepole pine, mountain hemlock and western white pine.
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 Shadow Lake in Lassen Volcanic National Park.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 1 to 2 inches, (2 to 6 cm)
Cambic horizon: 2 to 23 inches, (6 to 58 cm)
Andic soil properties: 2 to 23 inches, (6 to 58 cm)
Densic contact: 41 inches, (104 cm)
Particle-size control section: 1 to 40 inches, (2 to 102 cm)
Soil moisture control section: 11.5 to 41 inches (29 to 104 cm)
ADDITIONAL DATA: Classification and properties inferred from lab data from lab pedon number 07N0143 NSSL, Lincoln, NE. NASIS User Pedon ID in Davis, MLRA Office: 789262.