LOCATION ZWICKER COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Chromic Haplotorrerts
TYPICAL PEDON: Zwicker stony clay loam, in rangeland. (Colors are for dry soil unless otherwise noted.) The surface is covered by 10 percent cobbles and 5 percent stones.
A1--0 to 1 inch; light brown (7.5YR 6/4) stony clay loam, brown (7.5YR 5/4) moist; moderate very fine granular structure; soft, very friable, moderately sticky and moderately plastic; slightly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (1 to 4 inches thick)
A2--1 to 4 inches; light brown (7.5YR 6/4) clay loam, brown (7.5YR 5/4) moist; weak medium platy structure parting to moderate fine granular; soft, very friable, moderately sticky and moderately plastic; slightly effervescent; strongly alkaline (pH 8.8); clear smooth boundary. (0 to 5 inches thick)
Bss--4 to 10 inches; light brown (7.5YR 6/4) clay, brown (7.5YR 5/4) moist; weak coarse prismatic structure parting to moderate medium subangular blocky with slickensides; hard, firm, moderately sticky and moderately plastic; slightly effervescent; strongly alkaline (pH 8.6); gradual wavy boundary. (4 to 15 inches thick)
Bssky--10 to 17 inches; light brown (7.5YR 6/4) clay, brown (7.5YR 5/4) moist; weak coarse prismatic structure parting to moderate medium subangular blocky with slickensides; very hard, firm, moderately sticky and moderately plastic; few fine irregular seams and soft masses of calcium carbonate; many fine gypsum crystals; violently effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (3 to 15 inches thick)
Bky--17 to 32 inches; light brown (7.5YR 6/4) clay, brown (7.5YR 5/4) moist; massive; extremely hard, very firm, moderately sticky and moderately plastic; vertical cracks from the surface terminate in this horizon; many fine irregular seams and soft masses of calcium carbonate; many fine gypsum crystals; violently effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (0 to 20 inches thick)
Cr--32 inches; soft, fissile shale.
TYPE LOCATION: Montezuma County, Colorado; about 6 miles northeast of the Ismay Trading Post; located about 300 feet west and 900 feet south of the northeast corner of sec. 28, T. 36 N., R. 19 W.; Bowdish Canyon, Colorado USGS quad; lat. 37 degrees 21 minutes 16 seconds N. and long. 108 degrees 56 minutes 18 seconds W., NAD27
RANGE IN CHARACTERISTICS:
Soil moisture regime: typic aridic
Soil temperature regime: mesic
Mean annual soil temperature: 52 to 59 degrees F
Surface rock fragments: 0 to 60 percent
Particle-size control section: 35 to 60 percent clay
Depth to paralithic contact: 20 to 40 inches to soft shale
Depth to secondary calcium carbonate: 3 to 6 inches
Vertic features: cracks and slickensides
A horizon:
Hue: 5YR to 10YR
Value: 5 to 7 (3 to 6 moist)
Chroma: 3 or 4
Texture: clay loam or clay
Rock fragments: 0 to 35 percent
Calcium carbonate equivalent: 1 to 5 percent
Reaction: slightly to strongly alkaline
Bss (Bky when present) horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7 (3 to 6 moist)
Chroma: 3 or 4
Texture: clay or clay loam
Rock fragments: 0 to 15 percent
Calcium carbonate equivalent: 5 to 10 percent
Reaction: slightly to strongly alkaline
COMPETING SERIES: These are the Colona, Puerco and Unkee series. Colona, Puerco, and Unkee soils are very deep.
GEOGRAPHIC SETTING:
Parent material: alluvium and colluvium derived from calcareous shale
Landform: knobs, ridges, and hills
Slopes: 3 to 12 percent
Elevation: 5,000 to 5,700 feet
Mean annual temperature: 52 to 56 degrees F
Mean annual precipitation: 8 to 10 inches
Precipitation is fairly evenly distributed throughout the year with July and August being slightly wetter and June being slightly dryer.
Frost-free period: 135 to 160 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Claysprings and Mack soils. Claysprings soils have a paralithic contact at less than 20 inches. Mack soils are very deep.
DRAINAGE AND PERMEABILITY: well drained, medium to very high runoff, slow permeability
USE AND VEGETATION: These soils are used for grazing. Native vegetation is mainly shadscale, galleta, alkali sacaton, and saline wildrye.
DISTRIBUTION AND EXTENT: Southwest Colorado. LRR D, MLRA 35. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Cortez Area, Colorado, Parts of Dolores and Montezuma Counties 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: The zone from 0 to 4 inches. (A1 and A2)
Vertic feature: The zone from 1 to 17 inches. (A2, Bss, and Bssky).
Vertic features: intersecting slickensides, more than 30 percent clay in the control section, and 24 inch deep cracks.
Particle size control section: The zone from 10 to 32 inches. (Bssky, Cky)
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003