LOCATION RACE CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, micaceous, frigid Typic Dystroxerepts
TYPICAL PEDON: Race gravelly loam - on a south facing a slope of 45 percent under white fir, incense-cedar, and ponderosa pine, with a few Douglas-fir, at 4590 feet elevation. (Colors are for dry soil unless otherwise stated. When described on 5/22/79 the soil was moist throughout).
O1--1.5 to 0 inches; fresh and decomposing leaf and needle litter.
A1--0 to 6 inches; light olive gray (5Y 6/2) gravelly loam, dark olive gray (5Y 3/2) moist; moderate and strong coarse and medium granular structure; soft, very friable, slightly sticky and slightly plastic; few very fine and fine, common medium roots; many very fine and fine interstitial and tubular pores; 20 percent pebbles; neutral (pH 6.6); clear wavy boundary. (5 to 10 inches thick)
B1--6 to 10 inches; light brownish gray (2.5Y 6/2) gravelly loam, olive gray (5Y 4/2) moist; moderate fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many fine and medium, few coarse roots; many very fine interstitial and tubular pores; 20 percent pebbles; slightly acid (pH 6.4); clear wavy boundary. (4 to 10 inches thick)
B21--10 to 16 inches; pale yellow (5Y 7/3) gravelly loam, olive (5Y 4/3) moist; moderate fine to medium subangular blocky structure; soft, friable, slightly sticky and plastic; common fine and medium, few coarse roots; many very fine tubular pores; 20 percent pebbles, 10 percent cobbles; slightly acid (pH 6.4); gradual wavy boundary. (6 to 13 inches thick)
B22--16 to 30 inches; light gray (5Y 7/2) cobbly clay loam, olive (5Y 5/3) moist; moderate fine and medium subangular blocky structure; common fine, medium, and coarse roots; many very fine tubular pores; 10 percent pebbles, 20 percent cobbles; moderately acid (pH 6.0); gradual wavy boundary. (10 to 15 inches thick)
B3--30 to 40 inches; pale yellow (5Y 8/3) gravelly loam, olive (5Y 5/4) moist; weak fine and coarse subangular blocky structure; soft, firm, slightly sticky and slightly plastic; few fine and medium roots; common very fine tubular pores; 20 percent pebbles, 10 percent cobbles; moderately acid (pH 5.8); clear wavy boundary. (10 to 28 inches thick)
C--40 to 60 inches; white (5Y 8/1) gravelly silt loam, pale olive (5Y 6/3) moist; massive; soft, very friable, nonsticky and slightly plastic; common very fine tubular pores; 30 percent pebbles; moderately acid (pH 5.8)
TYPE LOCATION: Trinity County, California; on South Fork Mountain, on Forest road 2S02, approximately 0.8 mile west of the Cedar Gap junction, pit is upslope from road about 20 feet; SE 1/4, SE 1/4, sec. 29, T.28N., R.12W., MDBM.
RANGE IN CHARACTERISTICS: Depth to micaceous schist ranges from 40 to more than 60 inches. The mean annual soil temperature is estimated to be less than 47 degrees F., mean summer soil temperature is estimated to be 48 degrees to 50 degrees F., and the difference between the mean summer and mean winter soil temperature is estimated to be more than 9 degrees F. The soil between the depths of 7 and 20 inches is usually dry in all parts from mid-June to mid-October and moist in all parts from November to April in most years. The rock fragment content of the 10 to 40 inch control section is 10 to 35 percent. Base saturation is less than 60 percent.
The A horizon is 10YR 6/3, 7/2; 2.5Y 6/2; 5Y 6/2. Moist colors are 10YR 4/3, 3/3; 2.5Y 3/2; 5Y 3/2. It is loam or silt loam with 20 to 26 percent clay, 0 to 15 percent cobbles, and with 5 to 35 percent gravel. It is neutral to medium acid.
The B2 horizon is 2.5Y 7/2, 7/4; 5Y 5/3, 6/3, 7/2, 7/3, 7/4, 7/6, 8/3. Moist colors are 2.5Y 4/2, 5/4; 5Y 4/2, 4/3, 5/3, 5/6 6/4. It is loam, silty loam, clay loam, or silty clay loam, with 20 to 32 percent clay. It has 10 to 35 percent gravel and 5 to 20 percent cobbles. It is slightly or medium acid.
The C horizon is 2.5Y 6/2, 8/2, 8/4; 5Y 8/1, 8/6. Moist colors are 2.5Y 4/2, 4/4, 6/4; 5Y 6/3, 6/6. It is silt loam or silty clay loam with 15 to 35 percent gravel and 0 to 10 percent cobbles. It is slightly or medium acid.
COMPETING SERIES: See Remarks
GEOGRAPHIC SETTING: Race soils are on mountain sideslopes. Slopes are 30 to 75 percent. The soils formed in material weathered from micaceous schist. Elevation is 4500 to 5800 feet. The climate is subhumid mesothermal with warm dry summers and cool wet winters. Mean annual precipitation varies from 54 to 60 inches with some snowfall. Mean January temperature is 35 degrees F., mean July temperature is 63 degrees F., and mean annual temperature is 48 degrees F. Frost-free season is estimated to be about 100 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: See Remarks.
DRAINAGE AND PERMEABILITY: Well or moderately well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for timber production wildlife habitat, and watershed. Native vegetation is white fir, sadler oak, incense-cedar, ponderosa pine, and Douglas-fir.
DISTRIBUTION AND EXTENT: Northwestern California. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Trinity County, California, 1981, Six Rivers National Forest. Source of name is Race Track Saddle on South Fork Mountain.
REMARKS: The classification was updated in February 2001 using the Eighth Edition to Soil Taxonomy. This series was formerly classified as fine-loamy, micaceous, frigid Dystric Xerochrepts. Competing series were not checked at that time.
The base saturation (by Hack Kit), is about 40 percent at a depth of about 70cm. All horizons contain visible flecks of mica and exhibit a greasy feel characteristic of that mineral. The micaceous mineralogy is assumed. Clay does not increase sufficiently to qualify for an argillic horizon. 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.
OSED scanned by SSQA. Last revised by state on 6/81.