LOCATION PIEZON COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Ustic Haplocalcids
TYPICAL PEDON: Piezon loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A--O to 4 inches; brown (10YR 5/3) loam, dark brown (10YR 4/3) moist; weak fine granular structure; soft, very friable, sticky and plastic; 7 percent calcium carbonate equivalent; strongly effervescent; moderately alkaline (pH 8.4): abrupt smooth boundary. (2 to 4 inches thick)
Bw--4 to 13 inches; pale brown (10YR 6/3) loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure parting to moderate fine subangular blocky; slightly hard, friable, sticky and plastic; 15 percent calcium carbonate equivalent; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (4 to 10 inches thick)
Bk1--13 to 24 inches; very pale brown (10YR 7/3) loam, light yellowish brown (10YR 6/4) moist; moderate medium subangular blocky structure parting to moderate fine subangular blocky; slightly hard, friable, sticky and plastic; 5 percent channery fragments, 20 percent calcium carbonate equivalent; calcium carbonate disseminated and as common fine threads, violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (6 to 12 inches thick)
Bk2--24 to 30 inches; very pale brown (10YR 7/3) loam, light yellowish brown (10YR 6/4) moist; weak medium subangular blocky structure parting to weak fine subangular blocky; slightly hard, friable, sticky and plastic; 5 percent channery fragments; 20 percent calcium carbonate equivalent; calcium carbonate disseminated and as common fine threads, violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (5 to 16 inches thick)
Cr--30 inches; weakly consolidated, highly fractured thinly bedded sandstone.
TYPE LOCATION: Moffat County, Colorado; approximately 10 miles southwest of Powderwash, about 1,700 feet east and 1,900 feet north of the southwest corner of Sec. 1, T. 10 N., R. 99 W.; latitude: 40 degrees, 45 minutes, 11 seconds north; longitude: 108 degrees, 28 minutes, 13 seconds west.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 44 to 46 degrees F., and the mean summer soil temperature is 62 to 64 degrees F. Depth to the paralithic contact ranges from 20 to 40 inches. Depth to the calcic horizon ranges from 6 to 16 inches. The calcic horizon contains 15 to 25 percent calcium carbonate. The soil is commonly calcareous throughout. The particle-size control section is a loam, silt loam, or channery loam and averages 18 to 27 percent clay, 30 to 55 percent silt and 25 to 50 percent sand with less than 35 percent fine and coarser sand. Content of channery fragments averages 0 to 20 percent.
The A horizon has hue ot 2.5Y through 7.5YR, value of 5 or 6 dry, 3 or 4 moist, and a chroma of 2 or 3. Reaction is mildly alkaline or moderately alkaline.
The Bw horizon has hue of 2.5Y through 7.5YR, value of 5 or 6 dry, 4 or 5 moist, and a chroma of 3 or 4.
The Bk horizons have hue of 2.5Y through 7.5YR, value of 6 through 8 dry, 5 through 7 moist, and a chroma of 3 or 4.
COMPETING SERIES: These are the Luhon (CO), Rockinchair (WY), and Rootel (MT) series. The Luhon series lacks bedrock above 40 inches. The Rockinchair series has greater than 35 percent fine and coarser sand in the particle-size control section. The Rootel series has a lithic contact above 40 inches.
GEOGRAPHIC SETTINGS: Piezon soils are on hillslopes and plateaus. Slopes range from 0 to 15 percent. The soils formed in residuum derived from siltstone and fine grained sandstone. Elevation is 6,100 to 7,700 feet. The mean annual precipitation ranges from 9 to 15 inches. In areas where the mean annual precipitation is less than 11 inches, the soil receives additional moisture due to snow drift accumulations on the soil. The mean annual temperature ranges from 42 to 45 degrees F. The frost-free season is 75 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brownsto, Castello, and Yellowwash soils. Brownsto and Castello soils are deep. Yellowwash soil is shallow to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained: medium runoff: moderate permeability.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. The native vegetation is western wheatgrass, needleandthread, Indian ricegrass, Nevada bluegrass, prairie junegrass, bottlebrush squirreltail, and Wyoming big sagebrush.
DISTRIBUTION AND EXTENT: These soils occur in northwestern Colorado and southern Wyoming. The series is of small extent. Total area is about 7,500 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Moffat County (Moffat County Area), Colorado, 1992.
REMARKS: Diagnostic horizons recognized in this pedon are: the ochric epipedon - the zone from O to 4 inches; the calcic horizon - the zone from 13 to 30 inches; and the paralithic contact at 30 inches. Last updated by the state 11/93.