LOCATION FESTUS UTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Torrifluventic Haploxerolls
TYPICAL PEDON: Festus gravelly sandy loam on a 4 percent east facing slope--rangeland. (Colors are for air-dry soil unless otherwise stated).
The soil surface is covered with 50 percent gravel.
A1--0 to 7 inches; dark grayish brown (10YR 4/2) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium platy structure parting to weak fine subangular blocky; soft, friable, slightly sticky and slightly plastic; common medium, many fine and very fine roots; common medium, fine and very fine vesicular pores; 20 percent gravel; moderately alkaline (pH 8.0); clear smooth boundary. (4 to 10 inches thick)
A2--7 to 13 inches; dark brown (10YR 4/3) very gravelly loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common medium, many fine and very fine roots; common medium, fine and very fine tubular pores; 40 percent gravel; moderately alkaline (pH 8.0); clear wavy boundary. (5 to 10 inches thick)
C1--13 to 29 inches; brown (10YR 5/3) very gravelly coarse sandy loam, dark brown (10YR 4/3) moist; massive; soft, friable, nonsticky and nonplastic; common fine and very fine roots; few medium, common fine and very fine tubular and interstitial pores; 55 percent gravel; moderately alkaline (pH 8.1); gradual smooth boundary. (8 to 16 inches thick)
C2--29 to 37 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 4/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine and very fine roots; many fine and very fine tubular and interstitial pores; 25 percent gravel; slightly effervescent, carbonates are disseminated; moderately alkaline (pH 8.2); clear smooth boundary. (8 to 16 inches thick)
C3--37 to 60 inches; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 3/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; many fine and very fine tubular and interstitial pores; 10 percent gravel; slightly effervescent, carbonates are disseminated; moderately alkaline (pH 8.4)
TYPE LOCATION: Iron County, Utah; about 2.5 miles southeast of State Li ne Mine; 2,640 feet south and 100 feet east of the northwest corner of sec. 27, T. 32 S., R. 19 W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 47 to 52 degrees F., and the mean summer soil temperature is 65 to 71 degrees F. These soils are dry for 50 to 60 percent of the time the soil temperature at a depth of 20 inches is above 41 degrees F. They are usually dry in the moisture control section for 55 to 70 days during the 120 days following June 21. The soil moisture regime is xeric bordering on aridic.
The mollic epipedon is 10 to 20 inches thick. The particle size control section averages less than 18 percent clay and 35 to 50 percent gravel. Organic carbon content decreases irregularly with depth.
The A1 horizon has value of 4 or 5 dry and 2 or 3 moist, and chroma of 2 or 3. Texture is gravelly loam or gravelly sandy loam. It is slightly alkaline or moderately alkaline.
The A2 horizon has value of 4 or 5 dry and 2 or 3 moist, and chroma of 2 or 3. Texture is sandy loam, gravelly sandy loam, gravelly loam or very gravelly loam, It is slightly or moderately alkaline.
The C1 horizon has value of 3 or 4 moist and chroma of 3 or 4. Texture is gravelly sandy loam, very gravelly coarse sandy loam or very gravelly loamy coarse sand. It is slightly or moderately alkaline.
The C2 horizon has value of 5 or 6 dry and 3 or 4 moist, and chroma of 2 to 4. Texture is gravelly loam, very gravelly coarse sand, very gravelly sandy loam or very gravelly loamy coarse sand. It is slightly effervescent. It is slightly or moderately alkaline.
The C3 horizon has value of 5 or 6 dry and 3 or 4 moist, and chroma of 3 or 4. Texture is loam or very gravelly loam. It is slightly effervescent. It is slightly or moderately alkaline.
COMPETING SERIES: These are the Logy (WA) and Pelton (OR) series. Logy soils have a Bw horizon and have a sandy 2C horizon within 30 to 40 inches of the surface. Pelton soils have a particle size control section of 18 to 25 percent clay and a mean annual soil temperature of 52 to 54 degrees F.
GEOGRAPHIC SETTING: Festus soils are in drainageways on fan remnants at elevations of 6,100 to 6,650 feet. Slopes range from 2 to 8 percent. These soils formed in alluvium derived from mixed igneous rocks. The mean annual air temperature is 45 to 50 degrees F. Average annual precipitation is 10 to 12 inches. The freeze-free period is 100 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Wieland, Decathon and Buster series. All have argillic horizons and usually occur at slightly higher elevations on convex landscapes. Decathon soils have an indurated silica hardpan between a depth of 20 to 40 inches, and are fine-loamy in the particle size control section. Both the Wieland and Buster soils have strongly cemented silica layers between a depth of 20 to 40 inches. Wieland soils are fine textured in the particle size control section. Buster soils are fine-loamy in the particle size control section.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability.
USE AND VEGETATION: Used for rangeland and wildlife habitat. The native vegetation is mountain big sagebrush, Wyoming big sagebrush, bottlebrush squirreltail and Indian ricegrass.
DISTRIBUTION AND EXTENT: Southwestern Utah. MLRA 28A. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Iron County (Iron-Washington Area), Utah 1997. The series name is coined.
REMARKS: Diagnostic horizon and features recognized in this pedon are:
Mollic Epipedon - the zone from the soil surface to a depth of about 13 inches (A horizons).
Fluventic feature - an irregular decrease in organic carbon.
The classification is based on the "Keys to Soil Taxonomy, Eighth Edition, 1998". The cation exchange activity class is an estimate based on NASIS data.