LOCATION SKY CAEstablished Series
The Sky series consists of moderately deep, well drained soils that formed in colluvium over residuum weathered from andesitic tuff. The Sky soils are on the upper third of mountain slopes. Slopes range from 9 to 70 percent. The mean annual precipitation is about 1400 millimeters and the mean annual air temperature is about 5 degrees C.
TAXONOMIC CLASS: Medial-skeletal, amorphic Humic Xeric Vitricryands
TYPICAL PEDON: Sky gravelly medial sandy loam on a North facing (354 degree), 20 percent slope at an elevation of 2390 meters. When described on 06/19/2002 the soil was moist throughout. Colors are for moist soils unless otherwise noted.
Oi--0 to 3 cm; slightly decomposed plant material;
Oa--3 to 5 cm; highly decomposed plant material;
A--5 to 8 cm; gravelly medial sandy loam, very dark gray (7.5YR 3/1) broken face moist; massive; soft, friable, slightly sticky and slightly plastic; common fine and medium roots throughout; common very fine irregular pores; 5 percent cobbles and 15 percent nonflat subangular gravel; very strongly acid, pH 5.0 by pH meter 1:1 water; abrupt smooth bounday. (1 to 13 cm thick)
E--8 to 13 cm; gravelly medial sandy loam, dark grayish brown (10YR 4/2) broken face moist; weak medium subangular blocky and weak fine subangular blocky structure; soft, friable, nonsticky and nonplastic; common fine and many medium roots throughout; common very fine irregular pores; 20 percent gravel and 10 percent cobbles; strongly acid, pH 5.3 by pH meter 1:1 water; abrupt smooth bounday. (0 to 13 cm thick)
Bw1--13 to 38 cm; very stony medial sandy loam, dark brown (10YR 3/3) broken face moist; moderate medium subangular blocky and moderate fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common fine and medium roots throughout; 5 percent gravel and 20 percent cobbles and 25 percent stones; strongly acid, pH 5.3 by pH meter 1:1 water; gradual smooth bounday.
Bw2--38 to 61 cm; very stony medial sandy loam, dark yellowish brown (10YR 3/6) broken face moist; moderate fine subangular blocky and moderate medium subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common fine, medium and coarse roots throughout; 5 percent gravel, 20 percent cobbles, and 25 percent stones; strongly acid, pH 5.4 by pH meter 1:1 water; abrupt wavy bounday. (the combined thickness of the Bw horizons is 25 to 76 cm thick)
Cr--61 to 91 cm; dark brown (7.5YR 3/3) broken face moist; moderately cemented andesite.
TYPE LOCATION: Placer County, 39 degrees North latitude, 4 minutes, 20 seconds and 120 degrees, 13 minutes, 30 seconds West longitude, NAD27 - U.S.G.S Quad: Homewood, California.
RANGE IN CHARACTERISTICS:
Surface rock fragment content: 0 to 15 percent consisting of gravel, cobbles and stones.
Soil temperature: 3 to 6 degrees C.
Depth to paralithic contact: 50 to 100 centimeters
Reaction: very strongly to moderately acid.
Base saturation: commonly is 15 to 30 percent but varies from 3 to 50 percent.
Control section:
Rock fragments: average more than 35 percent throughout the control section but ranges from 15 to 70 percent in individual horizons.
Clay content: averages 2 to 10 percent clay
Mineralogy: amorphic
A horizon:
Hue: 10YR, 7.5YR
Value: 2 or 3 moist
Chroma: 1 through 3 moist
Organic matter: 7 to 34 percent
Texture of the fine earth fraction: course sandy loam or sandy loam
Content of rock fragments: 15 to 35 percent
5 to 30 percent gravel
0 to 20 percent cobbles
E horizon (where present):
Hue: 10YR
Value: 4 or 5 moist
Chroma: 2 through 4 moist
Organic matter: 1 to 8 percent
Texture of the fine earth fraction: course sandy loam or sandy loam
Content of rock fragments: 20 to 40 percent
10 to 30 percent gravel
5 to 25 percent cobbles
Bw horizons:
Hue: 10YR
Value: 3 or 4 moist
Chroma: 3 through 6 moist
Organic matter: 1 to 8 percent
Texture of the fine earth fraction: course sandy loam or sandy loam
Content of rock fragments: 35 to 60 percent
5 to 35 percent gravel
5 to 35 percent cobbles
5 to 35 percent stones
COMPETING SERIES: There are no other series in this family at this time.
GEOGRAPHIC SETTING: Sky soils are on the upper third of mountain slopes. Slopes are 9 to 50 percent. These soils formed in colluvium over residuum weathered from andesite. Elevation is 2105 to 2730 meters. The climate is humid to subhumid with warm dry summers and cold wet winters. Mean annual precipitation is 740 to 1700 millimeters, most of which occurs as snow. The mean annual temperature is 3 to 6 degrees C. Frost free season is 25 to 75 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Meiss, and Waca soils. The Meiss soils are shallow to bedrock and the Waca soils are lower on the mountainside and warmer (frigid).
DRAINAGE AND PERMEABILITY: well drained; high runoff class; moderately rapid permeability above the bedrock.
USE AND VEGETATION: Wildlife and recreation; native vegetation is mixed conifers. The principal species are California red fir and mountain hemlock.
DISTRIBUTION AND EXTENT: Lake Tahoe Basin of California in MLRA 22A. These soils are of minor extent. MLRA: 22
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Placer County, (Tahoe Basin Area), California, 2007. Source of name from "Lake of the Sky" in reference to Lake Tahoe.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle Size Control Section for this pedon: from the mineral soil surface to 100 cm below the starting point (the A1, A2 and Bw horizons)
Andic properties: 0 to 61 cm (the A, E, Bw1, and Bw2 horizons)
Umbric Epipedon: 5 to 38 cm (the A, E, Bw1 (after mixing the upper 18 cm the colors moist are 3/3 or darker))
Paralithic contact: 61 cm (Cr)
ADDITIONAL DATA:
Lab Pedon #: 03N1043