LOCATION CRESTVALE COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Gypsic Aquisalids
TYPICAL PEDON: Crestvale loam, rangeland. (Colors are for dry soil unless otherwise noted.)
Ayz--0 to 21 inches; very pale brown (10YR 7/3) loam, pale brown (10YR 6/3) moist; moderate fine granular structure; soft, very friable; many fine and very fine crystals of calcium sulfate disseminated and in small spots; 12 percent calcium sulfate; strongly effervescent; moderately alkaline; gradual smooth boundary. (10 to 24 inches thick)
Byz--21 to 30 inches; very pale brown (10YR 7/3) heavy loam, brown (10YR 5/3) moist; weak medium subangular blocky structure parting to weak fine granular; slightly hard, very friable; common fine spots of calcium sulfate; 2 percent calcium sulfate; strongly effervescent; moderately alkaline; clear smooth boundary. (3 to 12 inches thick)
Ckg--30 to 42 inches; light brownish gray (10YR 6/2) clay loam; grayish brown (10YR 5/2) moist; few fine faint yellowish brown (10YR 5/6) redox features; weak medium subangular blocky structure parting to weak fine subangular blocky; hard, friable, sticky and plastic; many fine pores; calcium carbonate visible in small spots and streaks; violently effervescent; moderately alkaline; clear smooth boundary. (7 to 24 inches thick)
Cg--42 to 60 inches; grayish brown (10YR 5/2) sandy loam, dark grayish brown (10YR 4/2) moist; few fine faint yellowish brown (10YR 5/6) redox features; massive; slightly hard, friable; strongly effervescent; moderately alkaline.
TYPE LOCATION: Saguache County, Colorado; about 4 miles north and 1 mile west of Moffat; 50 feet north and 1,750 feet west of the SE corner of Sec. 12, T. 44 N., R. 9 E. U.S.G.S. Moffat North quad.; Lat. 38 degrees, 04 minutes, 16 seconds N., and Long. 105 degrees, 55 minutes, 39 seconds W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 42 degrees to 46 degrees F., and the mean summer temperature at a depth of 20 inches ranges from 60 degrees to 64 degrees F. Calcium sulfate in the salic and gypsic horizons ranges from 10 to about 20 percent more than the underlying material. Soluble salts in the salic horizon range from 2 to 8 percent. Clay content in the particle-size control section ranges from 18 to 35 percent, and sand coarser than very fine sand ranges from 15 to 50 percent. Rock fragments range from 0 to 15 percent throughout the profile.
The Ayz horizon has hue of 10YR through 7.5YR, value of 5 through 7, 4 through 6 moist, and chroma of 3 or 4. It commonly is loam or light clay loam.
The Byz horizon has hue of 10YR or 7.5YR, value of 5 through 7, 4 through 6 moist, and chroma of 3 or 4. It is usually loam or clay loam.
The Ckg and Cg horizons have hue of 10YR through 7.5YR, value of 4 through 6, 4 or 5 moist, and chroma of 2 through 4. It commonly is clay loam to a depth of about 40 inches and sandy loam or light sandy loam below depths of 40 inches.
COMPETING SERIES: There are no other known series in this family.
GEOGRAPHIC SETTING: Crestvale soils are on low alluvial fans and terraces. Slopes are 0 to 2 percent. The soils formed in mixed alluvium. Elevation ranges from 7,700 to 8,000 feet. The mean annual temperature ranges from 40 to 42 degrees F., and the mean annual precipitation ranges from 8 to 10 inches. The frost-free period ranges from 90 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Harlem and Laney soils, both of which lack a salic or gypsic horizon.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; moderate permeability. The depth to the water table is normally between 2.5 and 3.5 feet during the growing season.
USE AND VEGETATION: Crestvale soils are used for native range. Some areas are irrigated successfully. Vegetation is dominated by alkali sacaton, inland saltgrass, and rabbitbrush.
DISTRIBUTION AND EXTENT: The San Luis Valley of south-central Colorado. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Saguache County Area, Colorado, 1981.
REMARKS: This revision updates the classification from a Cambic Gypsiorthid to be compatible with the 1994 revisions to National Soil Taxonomy. Diagnostic horizons and features recognized are: an ochric epipedon; a salic horizon from 0 to 21 inches; a gypsic horizon from 0 to 21 inches; watertable at 2.5 to 3.5 feet during the growing season; redox features from 30 to 60 inches; visible gypsum as crystals in the Ayz and Byz horizons; visible carbonates in the Ck horizon; an aquic moisture regime; and a frigid temperature regime. Last updated by the state 6/95.
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.