LOCATION PAROWAN UTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Oxyaquic Torriorthents
TYPICAL PEDON: Parowan silt loam - rangeland. (Colors are for air-dry soil unless otherwise stated).
A1--0 to 3 inches; brown (7.5YR 5/4) silt loam, brown (7.5YR 4/4) moist; weak moderately thick platy structure parting to weak thin platy; slightly hard, friable, slightly sticky and slightly plastic; common medium, few fine and very fine roots; common fine and very fine vesicular pores; moderately effervescent (12 percent calcium carbonate equivalent), carbonates are disseminated; moderately alkaline (pH 8.2); clear wavy boundary (3 to 4 inches thick).
A2--3 to 7 inches; brown (7.5YR 5/4) silt loam, dark reddish brown (5YR 3/4) moist; weak coarse subangular blocky structure parting to weak medium and fine subangular blocky; hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; few medium and common very fine pores; strongly effervescent (18 percent calcium carbonate equivalent), carbonates are disseminated; strongly alkaline (pH 8.6); clear wavy boundary (4 to 6 inches thick).
C1--7 to 16 inches; light brown (7.5YR 6/4) silty clay loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure parting to moderate fine and very fine subangular blocky; very hard, firm, sticky and plastic; common fine and few very fine roots; few fine and very fine pores; strongly effervescent (37 percent calcium carbonate equivalent), carbonates are disseminated; strongly alkaline (pH 8.8); clear smooth boundary (7 to 9 inches thick).
C2--16 to 22 inches; light reddish brown (5YR 6/4) silty clay loam, yellowish red (5YR 4/6) moist; moderate coarse subangular blocky structure parting to moderate medium and fine subangular blocky; very hard, very firm, sticky and plastic; common fine and few very fine roots; few fine and common very fine pores; strongly effervescent (35 percent calcium carbonate equivalent), carbonates are disseminated; strongly alkaline (pH 8.8); clear wavy boundary (4 to 7 inches thick).
C3--22 to 27 inches; light brown (7.5YR 6/4) silty clay loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure parting to moderate fine and very fine subangular blocky; very hard, firm, sticky and plastic; few fine and very fine roots; few medium, common fine and very fine pores; strongly efferescent(27 percent calcium carbonate equivalent), carbonates are disseminated; strongly alkaline (pH 8.6); clear wavy boundary (5 to 12 inches thick).
C4-27 to 34 inches; pink (5YR 7/4) silt loam, yellowish red (5YR 5/6) moist; weak medium subangular blocky structure parting to weak fine and very fine subangular blocky; hard, firm, sticky and plastic; few fine roots; few fine and common very fine pores; strongly effervescent (32 percent calcium carbonate equivalent), carbonates are disseminated; strongly alkaline (pH 8.8); abrupt wavy boundary (6 to 7 inches thick).
C5--34 to 49 inches; light reddish brown (5YR 6/4) silty clay loam, yellowish red (5YR 4/6) moist; common medium distinct brown (10YR 5/3) mottles; weak coarse subangular blocky structure; very hard, firm, sticky and plastic; few fine and very fine roots; few medium, common fine and very fine pores; strongly effervescent (30 percent calcium carbonate equivalent), carbonates are disseminated; strongly alkaline (pH 8.6); gradual wavy boundary (7 to 16 inches thick).
C6--49 to 60 inches; pink (5YR 7/4) silt loam, yellowish red (5YR 4/6) moist; common medium distinct light brown (7.5YR 6/4) mottles; massive; hard, friable, slightly sticky and plastic; few fine and very fine roots; common fine and very fine pores; violenty effervescent (43 percent calcium carbonate equivalent), carbonates are disseminated; strongly alkaline (pH 8.6).
TYPE LOCATION: Iron County, Utah; about 3 miles west- northwest of Paragonah, about 2,500 feet north and 1,020 feet east of the southwest corner of sec. 25, T. 33 S., R. 9 W. Paragonah Quadrangle, 37 degrees, 54 minutes north latitude and 112 degrees, 49 minutes west longitude.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches ranges from 47 to 52 degrees F., and the mean summer soil temperature ranges from 65 to 71 degrees F. In more than 7 out of 10 years, the moisture control section is continually dry in all parts more than 50 percent of the time when the soil temperature at the 20 inch depth is above 41 degrees F.
Parowan soils have a seasonal high water table at a depth of 40 to 60 inches, and are saturated with water in one or more layers within 60 inches for 1 month or more per year.
The particle size control section averages 27 to 35 percent clay and less than 15 percent fine sand or coarser. The soil is strongly effervescent or effervescent below a depth of 20 inches. Calcium carbonate equivalent ranges 15 to 40 percent in the particle size control section.
The A horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, and chroma of 3 or 4. It is moderately alkaline or strongly alkaline. Electrical conductivity ranges from 0 to 4 millimohos/cm.
The C horizon has hue of 10YR to 5YR, value of 5 to 7 dry and 4 or 5 moist, and chroma of 3 to 8. Texture is silty clay loam or silt loam. Few to many, fine or medium distinct mottles are present in one or more of the C horizons. Electrical conductivity ranges from 0 to 8 millimhos/cm.
COMPETING SERIES: These are the Needle Peak (NV) and Prida (NV) series. Needle Peak soils have less than 10 percent carbonates in the particle size control section. Prida soils have horizons of silica accumulations and durinodes.
GEOGRAPHIC SETTING: Parowan soils are on alluvial flats at elevations of 5,650 to 5,800 feet. Slopes range from 0 to 2 percent. These soils formed in alluvium derived dominantly from igneous and sedimentary 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 120 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ashdown and Calcross (T) series. These soils are not saturated with water at any time during the year, and occur on slightly higher positions on the landscape. Ashdown soils also have greater than 15 percent coarser than very fine sand in the particle size control section.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium runoff; slow permeability.
USE AND VEGETATION: Used for rangeland and wildlife habitat. A few areas are used for irrigated cropland. The native vegetation is rubber rabbitbrush, black greasewood, Wyoming big sagebrush, alkali sacaton, saltgrass and wiregrass. Irrigated crops include alfalfa and small grains.
DISTRIBUTION AND EXTENT: Southwestern Utah. These soils are inextensive. MLRA 28A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Iron County (Iron-Washington Area), Utah 1997. The series is named after the nearby town of Parowan.
REMARKS: The diagnostic features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to a depth of 7 inches (A horizons).
Oxyaquic feature - saturated with water in one or more layers within 60 inches for 1 month or more per year in 6 or more out of 10 years.
Calcareous feature - The fine earth fraction effervesces with cold dilute hcl at a depth of 10 to 20 inches.
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.