LOCATION COJAM COTentative Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, mesic Aquic Torriorthents
TYPICAL PEDON: Cojam loam, on a north facing, concave, 1 percent slope in pastureland at an elevation of 4540 feet. (Colors are for dry soil unless otherwise noted.) When described on March 31, 1993 the soil was saturated from the surface to 60 inches or more.
A--0 to 4 inches; light brownish gray (2.5Y 6/2) loam, light olive brown (2.5Y 5/3) moist; massive; soft, very friable, slightly sticky and slightly plastic; many fine to coarse roots throughout; strongly effervescent; moderately alkaline; abrupt smooth boundary. (3 to 8 inches thick)
C--4 to 12 inches; light gray (2.5Y 7/2 silt loam, light yellowish brown (2.5Y 6/3) moist; massive; soft, friable, slightly sticky and slightly plastic; common fine roots throughout; strongly effervescent; moderately alkaline; clear smooth boundary. (4 to 16 inches thick)
Cg1--12 to 24 inches; very pale brown (10YR 7/3) silty clay loam, brown (10YR 5/3) moist; many fine distinct dark yellowish brown (10YR 4/6) and yellowish brown (10YR 5/6) redox concentrations and common gray (5Y 5/1) redox depletions; massive; slightly hard, friable, slightly sticky and slightly plastic; common fine roots throughout; strongly effervescent throughout; moderately alkaline; gradual wavy boundary. (10 to 20 inches thick)
Cg2--24 to 36 inches; very pale brown (10YR 7/3) silty clay loam, brown (10YR 5/3) moist; many fine distinct brownish yellow (10YR 6/6) redox concentrations and common gray (5Y 5/1) redox depletions; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots throughout; 10 percent fine gravel; strongly effervescent; moderately alkaline; gradual wavy boundary. (10 to 20 inches thick)
Cg3--36 to 60 inches; very pale brown (10YR 7/3) silty clay loam, brown (10YR 5/3) moist; many fine distinct brownish yellow (10YR 6/6) redox concentrations and common gray (5Y 5/1) redox depletions; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots throughout; strongly effervescent; moderately alkaline. (12 to 36 inches thick)
TYPE LOCATION: Mesa County, Colorado; about 1/4 miles east of Mack, Colorado along the railroad right-away; located about 1450 feet east and 330 feet south of the northwest corner of sec. 30, T. 10 S., R. 3 W.; Mack, Colorado USGS quad; lat. 39 degrees 13 minutes 14 seconds N. and long. 108 degrees 51 minutes 44 seconds W., NAD 1927
RANGE IN CHARACTERISTICS:
Soil moisture regime: Aquic moisture regime. It is saturated to the surface with water for a period of at least 2 weeks during the time the soil temperature is above 40 degrees F.
Soil temperature regime: Mesic
Mean annual soil temperature: 48 to 52 degrees F
Mean annual summer soil temperature: 70 to 75 degrees F
Particle-size control section: 18 to 35 percent clay
Depth to redox concentrations: 0 to 15 inches
Depth to redox depletions: 0 to 15 inches
Water table: depth varies from 0 to 2 feet, kind is apparent, months are March through September.
A horizon:
Hue: 7.5YR to 2.5Y
Value: 5 to 7 dry, 4 to 6
Chroma: 1 to 3
Reaction: Slightly alkaline to moderately alkaline
C horizon:
Hue: 7.5YR to 2.5Y
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 1 to 4
Texture: SICL, L, CL, SCL, SIL with thin strata of SL and FSL in some pedons.
Rock fragments: 0 to 15 percent fine gravels
Reaction: Slightly alkaline to moderately alkaline
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Cojam soils.
Parent material: Alluvium derived from shale.
Landform: Footslopes, terraces, swales, alluvial fans.
Slopes: 0 to 3 percent
Elevation: 4400 to 5000 feet
Mean annual air temperature: 50 to 54 degrees F
Mean annual precipitation: 7 to 10 inches.
Frost-free period: 135 to 190 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sagers and Killpack series. Sagers soils occur on the same landscape and are well drained soils. Killpack soils are well drained and are moderately deep to weathered shale.
DRAINAGE AND PERMEABILITY: Poorly drained, slow runoff, moderately slow permeability.
USE AND VEGETATION: The major uses are for wildlife habitat and limited livestock grazing. Some of the native plants that occur are sedges, cattails, and wheatgrass.
DISTRIBUTION AND EXTENT: Western Colorado. LRR D, MLRA 34. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES PROPOSED: Mesa county, Colorado. 1997. The name was coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: The zone from 0 to 4 inches. (A horizon)
Redoximorphic features: High chroma redox concentrations and redox depletions.
Water table: The presence of an apparent water table from 0 to 2 feet during the months of March through September.
Taxonomy Version: Seventh Edition, 1996.
ADDITIONAL DATA: This soil was previously mapped as a wet phase of the Sagers series.