LOCATION CORTYZACK CO UTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Calcidic Argiustolls
TYPICAL PEDON: Cortyzack fine sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 2 inches; brown (7.5YR 4/4) fine sandy loam, dark brown (7.5YR 3/2) moist; weak fine subangular blocky structure parting to moderate medium granular; soft, very friable, slightly sticky and slightly plastic; neutral (pH 7.0); clear smooth boundary. (2 to 6 inches thick)
A2--2 to 9 inches; brown (7.5YR 4/4) fine sandy loam, dark brown (7.5YR 3/2) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; neutral (pH 7.2); clear smooth boundary. (4 to 8 inches thick)
Bt--9 to 21 inches; reddish brown (5YR 5/4) sandy clay loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure parting to moderate fine subangular blocky; hard, friable, sticky and slightly plastic; common faint clay films on faces of peds; slightly alkaline (pH 7.6); clear wavy boundary. (10 to 20 inches thick)
Btk--21 to 24 inches; light reddish brown (5YR 6/4) sandy clay loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure parting to moderate fine subangular blocky; slightly hard, friable, sticky and slightly plastic; few faint clay films on faces of peds; few fine threads of calcium carbonate; slightly effervescent; slightly alkaline (pH 7.8); abrupt wavy boundary. (0 to 7 inches thick)
Bk1--24 to 45 inches; pink (5YR 7/4) sandy clay loam, light reddish brown (7.5YR 6/4) moist; weak medium subangular block structure; slightly hard, friable, sticky and slightly plastic; 25 percent calcium carbonate equivalent; calcium carbonate is disseminated and segregated as common fine threads; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (15 to 25 inches thick)
Bk2--45 to 60 inches; light reddish brown (5YR 6/4) sandy clay loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure; soft, very friable, sticky and slightly plastic; 10 percent calcium carbonate equivalent; common fine filaments of calcium carbonate; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Moffat County, Colorado; about 32 miles west of Maybell; about 1,320 feet north and 2,400 feet west of the southeast corner of Sec. 19, T. 7 N. R. 100 W., 40 degrees, 32 minutes, 26 seconds north latitude; 108 degrees, 40 minutes, 19 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil moisture regime: ustic bordering on aridic
Mean annual soil temperature: 42 to 45 degrees F
Mean summer soil temperature: 61 to 63 degrees F
Particle-size control section: 18 to 32 percent clay
Depth to the calcic horizon: 20 to 40 inches and has 15 to 30 percent calcium carbonate equivalent
Thickness of the mollic epipedon: 8 to 14 inches
A horizon:
Hue: 5YR to 10YR
Value: 3 to 5 dry, 2 to 4 moist
Chroma: 1 to 3 dry or moist
Reaction: neutral to moderately alkaline
Bt horizon:
Hue: 5YR or 7.5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 1 to 6 dry or moist
Texture: L, SCL, or CL
Reaction: neutral to moderately alkaline
Bk horizon:
Hue: 2.5YR to 7.5YR
Value: 5 to 8 dry, 4 to 7 moist
Chroma: 2 to 4 dry or moist
Texture: sandy clay loam, fine sandy loam, clay loam, or loam
Reaction: moderately alkaline or strongly alkaline
Some pedons may have C horizons below 60 inches.
COMPETING SERIES: Current competitors are the Absarook, Beartooth, Bielenberg, Dooley, Fairfield, Farnuf, Felor, Hoppers, Hyalite, Livona, Martinsdale, Meagher, Pianohill, Reeder, Reedwest, Snakejohn, Trazuni, Vida, and Williams soils.
Competitors prior to the Seventh Edition, 1996 version of the Keys to Soil Taxonomy are the Beeno, Bookcliff, Bullflat, Burtoner, Clancy, Empredrado, Greenway, Gurney, Hangdo, Jeffcity, Lininger, Maudlin, Moen, Placerton, Sponseller, Trag, Tschicoma, Ulrant, Watrous, and Yegen soils.
Absarook, Burtoner, Gurney, Hoppers, Jeffcity, Maudlin, Moen, Pianohill, Watrous--moderately deep to a lithic contact
Beeno, Lininger, Placerton, Reeder, Reedwest--moderately deep to a paralithic contact
Beartooth, Dooley, Greenway, Livona, Meagher, Vida, Yegen--have hue 10YR or yellower throughout the soil
Bielenberg, Snakejohn--have a paralithic and/or lithic contact above 60 inches
Bookcliff, Clancy, Ulrant--deep to a lithic contact
Bullflat, Empredrado, Farnuf, Felor, Hangdo, Hyalite, Sponseller, Trag, Trazuni, Tschicoma, Williams--lack a calcic horizon
Fairfield--calcic horizon occurs above 20 inches
Martinsdale--has hue 10YR or yellower in the Btk and Bk horizons
GEOGRAPHIC SETTING: Cortyzack soils are on hills. The soils formed in eolian deposits and slope alluvium derived from sandstone. Slopes range from 1 to 25 percent. Elevation ranges from 6,800 to 8,200 feet. The mean annual precipitation ranges from 15 to 20 inches and is evenly distributed throughout the year. The mean annual temperature ranges from 40 to 45 degrees F. The frost-free period is 70 to 95 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Detra and Emlin soils. The Detra soils lack a calcic horizon and have mollic epipedons that are more than 16 inches thick. The Emlin soils have hues of 10YR or yellower in the mollic epipedon and in the argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; very low to medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. Native vegetation consists of needleandthread, western wheatgrass, muttongrass, prairie junegrass, Wyoming big sagebrush, and mountain snowberry.
DISTRIBUTION AND EXTENT: These soils occur in northwestern Colorado and northeastern Utah. LRR E, MLRA 47 and 48A. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Moffat County (Moffat County Area), Colorado, 1991.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: The zone from 0 to 9 inches. (A1 and A2 horizons)
Argillic horizon: The zone from 9 to 24 inches. (Bt and Btk horizons)
Calcic horizon: The zone from 24 to 45 inches. (Bk1 horizons)
These soils have an aridic ustic soil moisture regime. The color range for the dry values in the top 6 inches is 3 to 5, which overlaps with Aridic Argiborolls and Typic Argiborolls. This pedon has color values dry of 4 in the top 6 inches and thus is classified as a Typic Argiboroll.
The classification was changed from Typic Argiborolls to frigid Calcidic Argiustolls 12/98.
Taxonomic Version: Eighth Edition, 1998.