LOCATION SHADELEAF CAEstablished Series
TAXONOMIC CLASS: Fine, magnesic, mesic Typic Argixerolls
TYPICAL PEDON: Shadeleaf gravelly clay loam--on an east facing slope of 30 percent at 4,300 feet elevation under a cover of mixed conifers and grass. (Colors are for dry soil unless otherwise stated. When described 6/7/78 the soil was moist throughout.)
0--1/2 inch to 0; loose duff and litter of conifer needles. (0 to 3 inches thick)
A--0 to 2 inches; dark grayish brown (10YR 4/2) gravelly clay loam, very dark brown (10YR 2/2) moist; moderate fine subangular blocky parting to moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many fine and very fine interstitial pores; 25 percent pebbles; neutral (pH 7.0); abrupt smooth boundary. (1 to 3 inches thick)
AB--2 to 4 inches; dark grayish brown (10YR 4/2) very gravelly clay loam, very dark brown (10YR 2/2) moist; strong fine subangular blocky structure; slightly hard, friable, slightly sticky and plastic; many very fine and few fine roots; few medium interstitial and common fine tubular pores; 35 percent pebbles, 5 percent cobbles and stones; mildly alkaline (pH 7.5); abrupt smooth boundary. (2 to 7 inches thick)
BAt--4 to 9 inches; brown (10YR 4/3) very gravelly clay, dark brown (7.5YR 3/2) moist; strong medium and fine subangular blocky structure; hard, firm, slightly sticky and plastic; common very fine, fine, medium and coarse roots; few coarse interstitial and common fine tubular pores; many moderately thick clay films on peds and in pores; 30 percent pebbles, 7 percent stones and cobbles; mildly alkaline (pH 7.5) abrupt wavy boundary. (3 to 7 inches thick)
Bt--9 to 18 inches; dark yellowish brown (10YR 4/4) gravelly clay, dark yellowish brown (10YR 3/4) moist; weak coarse and medium prismatic paring to moderate coarse subangular blocky structure; extremely hard, very firm, sticky and very plastic; few very fine, fine, medium and coarse roots; few very fine and fine tubular pores; continuous thick clay films on peds and in pores; 20 percent pebbles; mildly alkaline (pH 7.5); clear wavy boundary. (9 to 19 inches thick)
BCt--18 to 23 inches; pale brown (10YR 6/3) gravelly clay with yellowish brown (10YR 5/4) variegations, yellowish brown (10YR 5/4) moist; weak coarse subangular blocky and medium prismatic structure; extremely hard, very firm, sticky and very plastic; few very fine and fine roots; few very fine tubular pores; continuous thick clay films on peds and in pores; 30 percent pebbles; mildly alkaline; (pH 7.8); clear wavy boundary. (4 to 8 inches thick)
Cr--23 inches; highly fractured and weathered ultramafic rock.
TYPE LOCATION: Siskiyou County, California; 7 miles west of Weed; road cut on IP road 3 miles above Stewart Springs; 1/4 mile east of the SW corner Section 2, T.41N., R.6W.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 8 to 17 inches thick. Depth to bedrock ranges from 20 to 40 inches. Rock fragments average less than 35 percent throughout the soil. The soil from a depth of 6 to 16 inches is dry for 45 or more consecutive days between June 22 and November 1. It is moist in all parts for 45 or more consecutive days from December 22 to May 15. The mean annual soil temperature is 49 to 55 degrees F.
The A horizon has dry color of 10YR 4/2, 5/4, or 5/3 and moist color of 10YR 2/2, 3/3, 3/1; 7.5YR 3/2. It is clay loam with 30 to 40 percent clay modified by 20 to 40 percent rock fragments. It is slightly acid through mildly alkaline. Base saturation is 85 to 95 percent.
The Bt horizon has dry color of 10YR 6/3, 5/2, 5/4, 4/4, 4/3, or 4/2 and moist color of 10YR 5/4, 3/2, 3/3. 3/4, or 2/5Y 3/2. It is 45 to 60 percent clay modified by 15 to 35 percent rock fragments. It is neutral or mildly alkaline and the base saturation is 85 to 95 percent.
COMPETING SERIES: There are no other soils in this family.
GEOGRAPHIC SETTING: Shadeleaf soils are on mountainous uplands with slopes of 20 to 50 percent. These soils are formed in material weathered from ultramafic rocks. Elevation ranges from 3,000 to 5,500 feet. The climate is Mediterranean with warm, dry summers and cool, moist winters. The annual precipitation is 30 to 40 inches. The snow fall is 10 to 20 inches. The mean January temperature is 31 degrees F. The mean July temperature is 64 degrees F. The mean annual temperature is 46 degrees to 53 degrees F. The frost-free season is 100 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: See remarks.
DRAINAGE AND PERMEABILITY: Well drained; moderate to rapid runoff; slow permeability.
USE AND VEGETATION: Limited timber, wildlife habitat, and rangeland. Principal vegetation is Jeffrey pine, incense-cedar, Douglas-fir, wedgeleaf ceanothus and bunchgrass.
DISTRIBUTION AND EXTENT: Klamath Mountains of California and possibly southern Oregon, 1981. The soils are not extensive. Their total acreage is about 3,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Siskiyou County. California, Shasta-Trinity and Klamath National Forests, 1983.
REMARKS: This series was established to map a new family in a survey area that classified soil map unit components only to the family level.
ADDITIONAL DATA: Base saturation of mollic epipedon by Hach Kit.
OSED scanned by SSQA. Last revised by state on 5/83.