LOCATION MADDEN CAEstablished Series
TAXONOMIC CLASS: Fine, magnesic, mesic Mollic Haploxeralfs
TYPICAL PEDON: Madden clay loam - on a northwest facing convex slope of 25 percent under Douglas-fir, incense-cedar and ponderosa pine at 3,100 feet elevation. (Colors are for dry soil unless otherwise stated. When described on 5/25/77 the soil was moist throughout.)
01--1 to 0 inches; fresh and decomposing needle litter.
A1--0 to 8 inches; brown (7.5YR 5/4) clay loam, dark brown (7.5YR 3/2) moist; moderate very fine and fine subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine, few fine roots; common very fine interstitial and tubular pores; neutral (pH 6.8); clear smooth boundary. (3 to 10 inches thick)
B1t--8 to 15 inches; brown (7.5YR 5/4) clay loam, dark reddish brown (5YR 3/4) moist; moderate very fine and fine subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine and fine, common medium and coarse roots; common very fine interstitial and tubular pores; very few moderately thick clay films on peds, few thin clay films in pores; neutral (pH 7.0); gradual smooth boundary. (4 to 10 inches thick)
B21t--15 to 24 inches; dark brown (7.5YR 4/4) clay loam, dark reddish brown (5YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine and fine, common medium and coarse roots; common very fine interstitial and tubular pores; few moderately thick clay films on peds, few thin clay films in pores; 5 percent cobbles; neutral (pH 7.0); clear smooth boundary. (5 to 12 inches
B22t--24 to 31 inches; dark yellowish brown (10YR 4/4) clay, dark brown (7.5YR 4/4) moist; moderate fine and medium subangular blocky structure; very hard, firm, very sticky and plastic; few fine, common medium and coarse roots; common very fine and fine tubular pores; continuous thin clay films in pores; neutral (pH 7.2); clear wavy boundary. (3 to 8 inches thick)
B23t--31 to 37 inches; yellowish brown (10YR 5/4) clay, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; hard, firm, very sticky and very plastic; few fine and common medium roots; common very fine and fine tubular pores; common thin clay films in pores; mildly alkaline (pH 7.5); abrupt wavy boundary. (4 to 12 inches thick)
R--37 inches; strongly fractured serpentinitic bedrock; fractures less than 10cm apart.
TYPE LOCATION: Trinity County, California; roadcut on Old Hennessy Road, about .2km west of the junction of four roads on ridge top; middle of sec. 8, T.5N., R.6E., HBM.
RANGE IN CHARACTERISTICS: Depth to sedimentary or serpentinitic rock ranges from 20 to 40 inches. The mean annual soil temperature is estimated to be 50 to 59 degrees F. The soil between the depths of 4 and 12 inches is usually dry in all parts from mid-June to mid-October and moist in all parts from November to April. The base saturation is 75 to 95 percent throughout.
The A horizon is 5YR 5/4; 7.5YR 5/4, 6/4. Moist colors are 5YR 3/3, 3/4; 7.5YR 3/2. It is loam or clay loam with 5 to 15 percent gravel. It is neutral or slightly acid. Where dry values of 5 and moist values of 3 occur, the surface horizons are too thin to qualify for a mollic epipedon.
The B2t horizon is 7.5YR 4/4, 5/4; 10YR 4/4, 5/4. Moist colors are 5YR 3/4; 7.5YR 4/4; 10YR 3/3. It is heavy clay loam or clay. It has sufficient clay increase to qualify for an argillic horizon. It has 5 to 15 percent gravel, 0 to 5 percent cobbles. It is slightly acid to mildly alkaline.
COMPETING SERIES: See Remarks.
GEOGRAPHIC SETTING: Madden soils are on mountain sideslopes and ridges. Slopes are 15 to 50 percent. The soils formed in material weathered from serpentinite. Elevations are 1,000 to 4,800 feet. The climate is subhumid mesothermal with warm dry summers and cool wet winters. Mean annual precipitation varies from 50 to 60 inches. Mean January temperature is 43 degrees F., mean July temperature is 59 degrees F., and mean annual temperature is 54 degrees F. Frost-free season is estimated to be about 100 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: See Remarks.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for watershed values, wildlife habitat, and some timber production. Native vegetation is Douglas-fir, incense-cedar, ponderosa pine, with some madrone, black oak, canyon live oak, and beargrass.
DISTRIBUTION AND EXTENT: Northwestern California. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Trinity County, California, 1981. Source of name is Madden Creek.
REMARKS: The base saturation is assumed to be more than 75 percent throughout the soil. This series was established to identify and map a new family in a survey area that classified soil map unit components only to the family level.
ADDITIONAL DATA: Reference sample sent to the Lincoln Laboratory, 1979. Sample No. S79CA23-3. Resampling is needed due to large discrepancy between field and lab. clay percent.
OSED scanned by SSQA. Last revised by state on 5/81.