LOCATION FONTANA CA
Established Series
Rev. GAW/WZB/LAB/ET
01/2023
FONTANA SERIES
The Fontana series is a member of the fine-loamy, mixed, thermic family of Calcic Haploxerolls. Typically, Fontana soils have dark grayish brown, slightly acid and mildly alkaline, clay loam A horizons and moderately alkaline, yellowish brown, shaly clay loam Cca horizons overlying shale at a depth of 28 inches.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Calcic Haploxerolls
TYPICAL PEDON: Fontana clay loam - annual grasses and forbs (Colors are for dry soil unless otherwise stated.)
A11--0 to 10 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky, plastic; many very fine, common fine and few medium roots; common very fine interstitial and few fine tubular pores; slightly acid (pH 6.5); clear smooth boundary. (8 to 11 inches thick)
A12--10 to 21 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky, plastic; common very fine and fine roots; many very fine interstitial and common tubular pores; about 10 to 15 percent by volume of soft weathered yellow (10YR 7/6) 1/4 to 1/2" shale fragments; few 3/8 to 1/2" pressure faces; matrix slightly effervescent with disseminated lime in lower half of the horizon; slightly alkaline (pH 7.5); clear wavy boundary. (9 to 13 inches thick)
C1ca--21 to 28 inches; yellowish brown (10YR 5/4) shaly clay loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky, plastic; common very fine and few fine roots; common fine interstitial and fine tubular pores; about 20 percent by volume weathered yellow (10YR 7/6) 1/2 to 1" shale fragments; matrix strongly effervescent with disseminated lime, common soft powdery threads, few small soft concretions, coatings on shale fragments; moderately alkaline (pH 8.0); abrupt wavy boundary. (4 to 17 inches thick)
C2--28 to 60 inches; yellow (10YR 7/6) platy shale; few very fine roots; in joints; weathered and fractured; easy to dig or cut with hand tools; strongly calcareous; moderately alkaline (pH 8.0).
TYPE LOCATION: San Bernardino County, California; 1 3/4 miles north of junction of Carbon Canyon Road and entrance to Western Hills Golf Course; NW1/4NW1/4SW1/4 sec. 19, T.2S., R.8W.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact ranges from 20 to 40 inches. Usually the soil between depths of 5 and 15 inches is moist in some part between early November and mid-May for an average of about 180 continuous days. It is dry all the rest of the year. The mean annual soil temperature at a depth of 20 inches is 63 degrees to 68 degrees F. and usually the minimum temperature in winter is not below 47 degrees F. A few vertical cracks 3/8 to 1/2 inch wide develop upon drying and extend to depths of 16 or 18 inches. Small pressure faces are present in some pedons. Organic matter content in the upper 10 inches of the A horizon ranges from 1.0 to 3.0 percent and decreases regularly to less than 1 percent between depths of 10 and 20 inches.
The A horizon is dark grayish brown, grayish brown or brown in 10YR or 2.5Y hue. It is slightly acid in the upper 10 inches and neutral or mildly alkaline in the lower part. In some pedons, a calcareous A13 horizon rests directly on the parent material.
The Cca horizon is yellowish brown, dark yellowish brown or brown. It is clay loam or silty clay loam with 5 to 20 percent shale fragments. Lime is disseminated and in threads, soft concretions, and coats some shale fragments. Calcium carbonate equivalent is less than 15 percent.
COMPETING SERIES: These are the
Gazos,
Linne,
Nacimiento,
San Benito, and
Sorrento series. Gazos soils lack free lime in all parts and have a mollic epipedon more than 20 inches thick. Linne soils are calcareous in all parts and have a chroma of less than 2. Nacimiento soils are calcareous throughout. San Benito soils have a paralithic contact 40 to 60 inches below the surface. Sorrento soils lack a paralithic contact.
GEOGRAPHIC SETTING: Fontana soils are on hilly, moderately steep to steep uplands with rounded tops at elevations of 900 to 1,600 feet. They formed in residuum weathered from calcareous shale and fine grained sandstone. The climate is dry subhumid mesothermal with cool moist winters and warm dry summers. The mean annual precipitation is 12 to 16 inches. Mean annual temperature is about 63 degrees F., average January temperature is about 51 degrees F., and average July temperature is about 76 degrees F. The average freeze-free season is 230 to 290 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Alo and
Gaviota soils and the competing
Nacimiento and
San Benito soils. Alo soils are fine textured, have deep cracks when dry, and intersecting slickenside faces. Gaviota soils have ochric epipedons and are less than 20 inches deep to hard sandstone.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Used mainly for grazing. Some areas are being used for homesites. Vegetation is annual grasses and forbs.
DISTRIBUTION AND EXTENT: Upland foothllls in southern California. The soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: San Bernardino County (Southwestern Part), California, 1972.
REMARKS: The Fontana soils would have been classified as Brunizems.
The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET
OSED scanned by SSQA. Last revised by state on 10/72
National Cooperative Soil Survey
U.S.A.