LOCATION CHRISTOPHER CA NVEstablished Series
The Christopher series consists of very deep, somewhat excessively drained soils that formed in glacial outwash derived from granodiorite. The Christopher soils are on glacial outwash terraces in the tahoe basin. Slopes range from 0 to 30 percent. The mean annual precipitation is about 660 millimeters and the mean annual air temperature is about 5 degrees C.
TAXONOMIC CLASS: Mixed, frigid Dystric Xeropsamments
TYPICAL PEDON: Christopher Loamy coarse sand on a southeast facing (136 degree), 3 percent slope at an elevation of 1981 meters. When described on 08/09/2002 the soil was dry throughout. Colors are for dry soils unless otherwise noted.
Oi--0 to 3 cm; Pine litter
A--3 to 20 cm; brown (10YR 5/3) loamy coarse sand, very dark grayish brown (10YR 3/2) moist; 85 percent sand; 14 percent silt; 1 percent clay; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; few very fine, fine and medium roots throughout; many very fine interstitial pores; 9 percent gravel; moderately acid, pH 6.0; abrupt smooth boundary. (8 to 25 cm thick)
Bw1--20 to 66 cm; yellowish brown (10YR 5/4) loamy coarse sand, brown (10YR 4/3) moist; 85 percent sand; 14 percent silt; 1 percent clay; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; few fine and common medium and very coarse roots throughout; many very fine interstitial pores; 2 percent cobbles 6 percent gravel; moderately acid, pH 5.7; clear smooth boundary.
Bw2--66 to 107 cm; yellowish brown (10YR 5/4) loamy coarse sand, dark yellowish brown (10YR 4/4) moist; 80 percent sand; 17 percent silt; 3 percent clay; moderate medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; few fine and medium roots throughout; many very fine interstitial pores; 2 percent cobbles 7 percent gravel; moderately acid, pH 5.9; clear wavy boundary.
Bw3--107 to 155 cm; yellowish brown (10YR 5/4) loamy coarse sand, dark yellowish brown (10YR 4/4) moist; 80 percent sand; 18 percent silt; 2 percent clay; moderate fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; few fine, very fine and very coarse roots throughout; many very fine interstitial pores; 9 percent gravel and 5 percent paracobbles; slightly acid, pH 6.1 (the combined thickness of the Bw horizons is 76 to 191 cm thick)
TYPE LOCATION: El Dorado County, California, 2418 feet south and 1849 feet west of Section 21, Township 12 N., Range 18 E., 38 degrees 52, minutes, 28.97 seconds north latitude and 119 degrees, 59 minutes, 37.41 seconds west longitude, NAD83 - U.S.G.S Quad: South Lake Tahoe, Calif. - Nev.
RANGE IN CHARACTERISTICS:
Soil moisture: usually moist between depths of about 12 and 35 inches but is dry in all parts from late June until mid-October
Soil temperature: 5 to 8 degrees C.
Control section:
Reaction: Strongly acid to Slightly acid.
Rock fragments: 1 to 15 percent, with 2 to 15 percent gravel, 0 to 10 percent cobbles and paracobbles, individual horizons more have more fragments.
Clay content: averages 0 to 7 percent clay
Mineralogy: mixed
A horizon(s):
Hue: 10YR
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 3 or 4 dry; 2 or 3 moist
Organic matter: 1 to 5 percent
Texture (less than 2 mm): Loamy coarse sand or loamy sand
Clay content: 0 to 5 percent
Content of rock fragments: 1 to 30 percent
0 to 5 percent cobbles
1 to 10 percent gravel
Bw horizons:
Hue: 10YR
Value: 4 through 6 dry; 4 or 5 moist
Chroma: 3 or 4 dry; 3 or 4 moist
Organic matter: 0.25 to 1.25 percent
Texture (less than 2 mm): Loamy coarse sand or Loamy sand
Clay content: 0 to 7 percent
Content of rock fragments: 1 to 30 percent
0 to 10 percent cobbles
1 to 10 percent gravel
C horizon where present:
Hue: 10YR
Value: 4 through 6 dry; 4 or 5 moist
Chroma: 3 or 4 dry; 3 or 4 moist
Organic matter: 0.25 to 1 percent
Texture (less than 2 mm): Loamy coarse sand
Clay content: 1 to 5 percent
Content of rock fragments: 10 to 55 percent
COMPETING SERIES: These are the Cagwin and Cassenai soils. Cagwin is 20 to 40 inches to soft bedrock. Cassenai is formed in colluvium on mountainslopes and has 15 to 35 percent fragments in the control section.
GEOGRAPHIC SETTING: Christopher soils are on glacial outwash terraces. Slopes are 0 to 30 percent. These soils formed in colluvium, alluvium and glacial outwash weathered from granodiorite. Elevation is 1895 to 2090 meters. The climate is subhumid with cool dry summers and cold moist winters. Mean annual precipitation is 530 to 990 millimeters. The mean annual temperature is 5 to 8 degrees C. Frost free season is 40 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gefo, Jabu, Marla and Oneidas soils. The Gefo soils have an umbric epipedon. Jabu and Oneidas soils have argillic horizons. Marla is somewhat poorly drained.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very low to medium runoff; rapid permeability. The soils are not flooded.
USE AND VEGETATION: This soil is used for wildflife, recreation, timber, and urban development. Vegetation is predominantly Jeffrey pine with an understory of green leaf manzanita, antelope bitter brush, mountain whitethorn, mahala mat, mules ear and lupin spp.
DISTRIBUTION AND EXTENT: These soils are of minor extent in the Tahoe Basin of California and Nevada in MLRA 22A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: El Dorado County, (Tahoe Basin area), California. The Source of the name is from a local lake.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle Size Control Section for this pedon: 28 to 103 cm, portions of the Bw1, Bw2, and Bw3