LOCATION WILDMAD CATentative Series
TAXONOMIC CLASS: Loamy-skeletal, magnesic, mesic Lithic Mollic Haploxeralfs
TYPICAL PEDON: WildMad very gravelly loam on a 18 percent northeast facing mountain side slope under a cover of Idaho fescue and scattered Jeffery Pine and incense cedar at an elevation of 3,800 feet. (Colors are for dry soil unless otherwise noted). When described on August 22, 1999 the soil was dry throughout.
Oi-0 to 1 inch; partially decomposed pine needles.
A-1 to 3 inches; brown (7.5YR 4/4), very gravelly loam, dark brown (7.5YR 3/3) moist; massive; soft, very friable, slightly sticky and nonplastic; very few very fine roots, few fine interstitial and very few fine tubular pores; 40 percent gravel, 8 percent cobbles, 3 percent stones; slightly acid (pH 6.4); abrupt smooth boundary.
AB-3 to 6 inches; strong brown (7.5YR 4/6) very gravelly loam, dark reddish brown (5YR 3/4) moist; weak, very fine, subangular blocky structure, slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; 30 percent gravel, 6 percent cobbles, 2 percent stones; neutral (pH 6.8); gradual, smooth boundary.
Bt-6 to 12 inches; yellowish red (5YR 5/6) very cobbly loam, reddish brown (5YR 4/4) moist; moderate, very fine, subangular blocky structure; slightly hard, friable, sticky and slightly plastic; few fine and medium roots; 10 percent gravel, 30 percent cobbles, 15 percent stones; neutral (pH 7.0); abrupt, irregular boundary.
R-12 inches; highly fractured, hard serpentinized peridotite.
TYPE LOCATION: Trinity County, California; about 2 miles south of Wildwood, CA, approximately 440 feet south and 20 feet east of the northwest corner of Section 11, T.29N., R.11W., MDB&M Latitude 40 degrees, 33 minutes, 55 seconds North; Longitude 128 degrees, 15 minutes, 18 seconds West. Dubakella Mountain, East Quadrangle (7.5 minute series).
RANGE IN CHARACTERISTICS:
Depth to lithic contact: 9 to 20 inches.
The mean annual soil temperature: 48 to 59 degrees F.
The soil moisture control section is dry in all parts from about July 1 to about September 30 (about 78 days).
The particle size control section: averages 20 to 34 percent clay and 40 to 80 percent rock fragments, mostly gravel.
Mineralogy: magnesic.
Organic matter: ranges from 3 to 6 percent to a depth of 6 inches.
Base saturation: ranges from 50 to 70 percent (by ammonium acetate).
Ca/Mg ratios: range from 0.20 to 0.23 in the top 6 inches.
Rock fragments on the surface: range from 15 to 50 percent gravel, 5 to 30 percent cobbles, and 0 to 10 percent stones.
A horizon:
Hue- 2.5YR to 7.5YR (dry or moist)
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 4 or 5 dry, 3 to 6 moist
Texture - gravelly silt loam, gravelly sandy loam, very gravelly loam, very cobbly loan, very stony loam, extremely gravelly loam or extremely cobbly loam
Clay content - 10 to 26 percent
Rock fragments - 15 to 40 percent gravel, 5 to 35 percent cobbles, 1 to 10 percent stones
Reaction - moderately acid to neutral
Bt horizon:
Hue- 2.5YR through 7.5YR (dry or moist)
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 5 or 6 dry, 4 or 6 moist
Texture - very gravelly sandy loam, very gravelly loam, very cobbly loam, very cobbly clay loam, very stony clay loam, extremely gravelly loam, extremely gravelly clay loam, extremely cobbly loam
Clay content - 20 to 35 percent
Rock fragments - 20 to 50 percent gravel, 10 to 40 percent cobbles, 2 to 15 percent stones
Reaction - neutral
COMPETING SERIES: There are no other series in this family at this time.
GEOGRAPHIC SETTING: WildMad soils are on mountainside slopes, ridges, and structural benches. Slopes are 5 to 60 percent. These soils formed in residuum weathered from serpentinized peridotites. Elevation is 3,450 to 5,250 feet. Mean annual precipitation is 39 to 59 inches. The mean annual temperature is 50 to 62 degrees F. Frost-free season is 90 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Dubakella soil. Dubakella soils are on convex and plane mountainsides. Dubakella soils are moderately deep and have clayey subsoils with greater than 35 percent rock fragments.
DRAINAGE AND PERMEABILITY: well drained; moderate to high runoff; moderate permeability.
USE AND VEGETATION: This soil is used for wildlife and watershed. Vegetation is open conifer forest of Jeffrey pine and incense cedar with shrubs and Idaho fescue.
DISTRIBUTION AND EXTENT: Trinity County, California and occurs in the M261B subsection of the M261Ba section. MLRA 5. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Trinity County, California 2001. Source of name from a local road.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Orchric epipedon - zone from 1 to 6 inches (A and AB horizons).
Argillic horizon - zone from 6 to 12 inches (Bt horizon).
Particle-size control section - zone from 1 to 12 inches (A, AB, Bt horizons).
The soil moisture control section - zone from 1 to 12 inches (A, AB, Bt horizons).
ADDITIONAL DATA: Lab analysis by DANR Analytical Laboratory work reference # 90S371.