LOCATION SPAA UT+IDEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, frigid Lithic Haploxerolls
TYPICAL PEDON: Spaa silt loam - irrigated (Colors are for dry soil unless otherwise noted.)
Ap--0 to 8 inches; brown (10YR 4/3) heavy silt loam, dark brown (10YR 3/3) moist; weak coarse blocky structure that parts to moderate medium and fine subangular blocky structure; slightly hard, friable, sticky, slightly plastic; many fine roots; noncalcareous in much of the soil mass with some seams of lime; mildly alkaline (pH 7.8) abrupt smooth boundary. (4 to 9 inches thick)
A12--8 to 15 inches; brown (10YR 4/3) silt loam, dark brown (10YR 3/3) moist; moderate coarse blocky structure that parts medium subangular blocky structure; hard, firm, sticky, slightly plastic; common fine roots; noncalcareous in much of the soil mass with some travertine fragments; moderately alkaline (pH 8.2); clear smooth boundary. (4 to 7 inches thick)
Cca--15 to 17 inches; brown (10YR 5/3) loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, firm, sticky, slightly plastic; common fine roots; strongly calcareous with segregated lime as veins and splotches; moderately alkaline (pH 8.5); abrupt wavy boundary. (2 to 6 inches thick)
R--17 to 18 inches; layer or irregular masses of travertine.
TYPE LOCATION: Wasatch County, Utah; 4,900 feet east of Midway Post Office, north of highway; 1,885 feet north and 1,260 feet west of the SE corner of sec. 35, T.35., R.4E.
RANGE IN CHARACTERISTICS: The soil is 10 to 20 inches deep over laminated travertine deposits. The mollic epipedon is 7 to 17 inches thick. The mean annual soil temperature is about 45F. and the mean summer temperature about 63 degrees F. The soils are usually moist but are dry in all parts of the 7 to 20 inch section or to the bedrock for more than 60 consecutive days in more than 7 out of 10 years.
The Al horizon has value of 4 or 5 dry, and chroma of 2 or 3. It has weak or moderate coarse blocky structure that parts to moderate medium and fine subangular blocky structure. This horizon is mildly or moderately alkaline and is slightly calcareous or noncalcareous.
The C horizon has hue of 5YR through 10YR, value of 4 through 7 dry, 3 and 4 moist, and chroma of 2 or 3. It is loam or silt loam and contains few to 20 percent gravel size travertine fragments, Weak accumulations of soft lime occur as veins and splotches. The travertine bedrock restrict roots and water penetration.
COMPETING SERIES: These are the Kuhl, Bakeoven, and Lickskillet series. These soils have a mean annual soil temperature of 47 degrees F. or more. Bakeoven and Lickskillet have more than 35 percent rock fragments in the control section.
GEOGRAPHIC SETTING: Spaa soils are on gently sloping to moderately steep terraces at elevations of 5,500 to 5,800 feet. They formed in residuum derived from travertine deposits. The climate is moist subhumid with an average precipitation of 16 to 20 inches falling mostly as snow. The mean annual temperature is 44 to 47 degrees F. and the mean summer temperature is about 63 degrees F. The frost free period is 70 to 90 days
PRINCIPAL ASSOCIATED SOILS: These are the Kovich soils and Rockland. Kovich soils have characteristics of wetness within 20 inches and are more than 40 inches deep to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability above the travertine.
USE AND VEGETATION: These soils are used for small irrigated gardens, some pastures, alfalfa, and small grain, and for rangeland. Several localized areas are used for warm spring recreational resorts. Native plants are native bluegrasses, Indian ricegrass, squirreltail, slender wheatgrass, needle-and-thread grass, phlox, sego lily, big sagebrush, bitterbrush, serviceberry, and yellowbrush.
DISTRIBUTION AND EXTENT: Cool mountain valleys in north-central Utah and possibly south-central Idaho where travertine deposits occur. This series is inextensive,
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Heber Valley Area, Utah, 1972.
REMARKS: Spaa soils were previously classified as Rendzinas.
OSED scanned by NSSQA. Last revised by state 6/72.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Lakewood MLRA office, without review of the soil series property data. The remainder of this document has not been updated.