LOCATION SOULAJULE CAEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, active, mesic Ultic Haploxeralfs
TYPICAL PEDON: Soulajule clay loam, on a SW facing convex slope of 15 percent slopes under ryegrass, soft chess, ripgut brome, plantain, lupine, and clover at 180 feet elevation. (Colors are for dry soil unless otherwise stated. When described (1/21/76) the soil was moist throughout.)
Ap--0 to 7 inches; reddish brown (5YR 5/4) clay loam, reddish brown (5YR 4/4) moist; moderate fine subangular blocky structure; hard, friable, sticky and plastic; many very fine and fine roots; many very fine and fine interstitial pores; 5 percent pebbles; strongly acid (pH 5.5); clear wavy boundary. (5 to 9 inches thick)
A12--7 to 17 inches; reddish brown (5YR 5/4) clay loam, reddish brown (5YR 4/4) moist; moderate fine and medium granular structure; slightly hard, very friable, sticky and plastic; common very fine and fine roots; many very fine and fine interstitial and vesicular pores; 5 percent pebbles; moderately acid (pH 5.8); clear irregular boundary. (6 to 12 inches thick)
B21t--17 to 22 inches; reddish brown (5YR 5/4) gravelly clay, mixed colors of yellowish red and reddish brown (5YR 4/4, 4/6) moist; weak fine and medium subangular blocky structure parting to weak medium granular; hard, firm, very sticky and very plastic; common very fine and fine roots; many very fine interstitial and vesicular pores; common thin clay films in pores and on peds; 30 percent pebbles; slightly acid (pH 6.5); gradual irregular boundary. (3 to 11 inches thick)
B22t--22 to 28 inches; yellowish red (5YR 5/6) very gravelly clay, yellowish red (5YR 4/6) moist; moderate fine subangular blocky structure; hard, firm, very sticky, and very plastic; few very fine and fine roots; common very fine interstitial pores; common thin clay films in pores and on peds; 50 percent pebbles; slightly acid (pH 6.5); gradual irregular boundary. (5 to 11 inches thick)
Cr--28 to 36 inches; deeply weathered sandstone; clay occurs in fractures.
TYPE LOCATION: Marin County, California; 7.1 miles north of Pt. Reyes Station on Hwy 1 and 1/4 mile east of Hwy 1; 122 degrees 51' 55'' W latitude and 38 degrees 08' 05'' N longitude.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact of sandstone or shale is 20 to 40 inches. The mean annual soil temperature is about 52 degrees to 58 degrees F. The soil between the depths of 6 and 17 inches is usually dry in all parts from July until October and is moist in some or all parts the rest of the year. Base saturation is less than 50 percent but never below 35 percent above the paralithic contact. Clay content averages 35 to 50 percent in the particle-size control section.
The A horizon has dry color of 7.5YR 5/4, 5/6; 5YR 4/4; 5YR 3/4 or 4/4. Gravel ranges from 0 to 15 percent. This horizon is slightly acid to strongly acid.
The B2t horizon has dry color of 7.5YR 5/4, 6/6; 5YR 5/4, 5/6 or 7/8 and moist color of 5YR 3/3, 3/4, 4/4, 4/6 or 6/6. It is gravelly clay loam, gravelly clay, very gravelly clay loam or very gravelly clay. Rock fragments are mostly gravel and range from 25 to 60 percent. This horizon is slightly acid or moderately acid.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Soulajule soils are on hills. Slopes are 9 to 75 percent. The soils formed in material weathered from strongly fractured soft sandstone and shale. Elevations are from sea level to 1,300 feet. The climate is subhumid mesothermal with warm dry summers and cool moist winters. Mean annual precipitation is 25 to 35 inches. Mean January temperature is about 51 degrees F.; mean July temperature is about 67 degrees F.; mean annual temperature is about 56 degrees F. Frost-free season is 260 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Los Osos, Olompali and Yorkville soils. Los Osos soils have a mollic epipedon and have a fine particle-size control section. Olompali soils have an abrupt A/B horizon boundary and have a fine particle-size control section. Yorkville soils have a thermic soil temperature and have a fine particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; slow permeability.
USE AND VEGETATION: Used for range and wildlife habitat. Native vegetation is annual grasses and forbs.
DISTRIBUTION AND EXTENT: Central and northern coastal California. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Marin County, California, 1979.
REMARKS: The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET