LOCATION SMOKEY CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Dystroxerepts
TYPICAL PEDON: Smokey gravelly sandy loam - on a south facing slope of 10 percent under mixed conifers at 6,400 feet elevation. (Colors are for dry soil unless otherwise stated. The soil was described on November 12, 1974).
01--1 to 0 inches; litter and duff. (1 to 3 inches thick)
A--0 to 4 inches; brown (10YR 4/3) gravelly sandy loam, dark brown (10YR 3/3) moist; moderate coarse granular structure; slightly hard, friable, nonsticky and slightly plastic; common very fine and fine roots; common very fine intrstitial pores; 18 percent pebbles; strongly acid (pH 5.2); clear smooth boundary. (3 to 6 inches thick)
Bt--4 to 14 inches; light yellowish brown (10YR 6/4) very gravelly loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, and coarse roots; common fine interstitial and tubular pores; common thin clay films lining pores; 40 percent pebbles; very strongly acid (pH 5.0); clear irregular boundary. (8 to 14 inches thick)
C--14 to 24 inches; yellow (10YR 7/6) very gravelly silt loam, brownish yellow (10YR 6/6) moist; massive, slightly hard, friable, sticky and plastic; common medium and coarse roots; few very fine and fine interstitial and tubular pores; 60 percent pebbles; very strongly acid (pH 4.5); abrupt wavy boundary. (9 to 20 inches thick)
Cr--24 to 36 inches; weathered metasedimentary rock, fractured with some roots in the cracks 7 to 10 inches apart.
TYPE LOCATION: Placer County, Tahoe National Forest, California; 2.4 miles east of the intersection of American Hill Road and Secret Ridge Road, near the center of section 5, T.15 N., R.13 E., MDB&M.
RANGE IN CHARACTERISTICS: The depth to a paralithic contact is 20 to 40 inches. Base saturation is less than 60 percent throughout the profile. The epipedon is ochric either because moist chromas are greater than 3.5 or it is too thin to be mollic or umbric. Stones and cobbles range from 0 to 20 percent and gravel ranges from 10 to 60 percent throughout the profile. Concentration of gravel increases with depth. The mean annual soil temperature is 43 to 46 degrees F. The soil is usually moist but is dry in all parts between depths of 10 to 24 inches from late July until early October. Reaction is medium acid to very strongly acid throughout.
The A horizon has color of 10YR 5/3, 4/3, 3/3; 7.5YR 5/4, 4/4, or 4/3 dry, and 10YR 3/3, 3/2; 7.5YR 5/4, 5/3; 5YR 5/4, or 4/4, 3/2, 3/4 moist. It is sandy loam silt loam or loam and may be gravelly or very gravelly.
The Bt horizon has color of 10YR 6/4, 6/6, 5/4, 5/6; 7.5YR 6/4, 5/4 or 4/4 dry and 10YR 5/6, 5/4; 7.5YR 4/4, 5/4; 5YR 4/6, or 5/6 moist. It is loam or silt loam and is gravelly or very gravelly.
The C horizon has color of 10YR 7/6, 6/6, 6/4, 6/3 or 7.5YR 4/4 dry and 10YR 6/6, 5/6, 6/4, or 6/3 moist. It is silt loam, sandy loam or loam modified by 40 to 60 percent gravel.
COMPETING SERIES: These are the Althouse, Icicle, Jayar, Jumpe, Kamela, Minaloosa, Treble and Umpa series. Althouse, Jumpe, and Treble soils are all deeper than 40 inches to bedrock. Icicle soils are neutral or slightly acid throughout. Jayar soils are slightly to medium acid and average 18 to 30 percent clay in the B horizon. Kamela soils have a lithic contact between 20 and 40 inches and have 20 to 27 percent clay in the B horizon. Minaloosa soils are deeper than 40 inches and are medium acid in the B horizon. Kamela soils have a lithic contact between 20 and 40 inches and have 20 to 27 percent clay in the B horizon. Minaloosa soils are deeper than 40 inches and are medium acid in the B horizon. Umpa soils average less than 18 percent clay in the control section.
GEOGRAPHIC SETTING: Smokey soils are on mountains. Slopes are 5 to 50 percent. The soils formed in material weathered from metasedimentary rocks. Elevations are 5,500 to 7,200 feet. The climate is subhumid, typified by warm dry summers and cold moist winters. The mean annual precipitation is 60 to 75 inches, most of which occurs as snow. Average annual January temperature is 33 degrees F, average annual July temperature is 64 degrees F and mean annual temperature is 42 to 47 degrees F. Frost-free season is about 75 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Hurlbut, Deadwood, Mariposa, Waca and Woodseye soils. Hurlbut, Deadwood and Mariposa soils have mean annual soil temperatures warmer than 4 degrees F. Waca soils have umbric epipedons and are dominated by amorphous materials. Woodseye soils are less than 20 inches to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: Used for watershed, timber production and wildlife habitat. Vegetation is primarily semi-open stands of mixed conifers and shrubs; Jeffrey pine, sugar pine, white fir, red fir, huckleberry oak, and pinemat manzanita.
DISTRIBUTION AND EXTENT: Mountainous areas of Northern California. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISED: Tahoe National Forest (Placer County), California, 1982.
REMARKS: CEC activity class estimated.