LOCATION COALIAMS WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Torrifluventic Haplustolls
TYPICAL PEDON: Coaliams loam-rangeland. (Colors are for dry soil unless otherwise stated)
Ap--0 to 8 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; weak medium granular structure; slightly hard, very friable; many fine and very fine roots; slightly effervescent; slightly alkaline (pH 7.6); abrupt wavy boundary. (4 to 8 inches thick)
Bw--8 to 24 inches; brown (10YR 5/3) loam stratified with sandy loam and clay loam, brown (10YR 4/3) moist; weak medium prismatic structure; hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; strongly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (7 to 18 inches thick)
Bk--24 to 60 inches; grayish brown (2.5Y 5/2) loam stratified with sandy loam and clay loam, very dark grayish brown (2.5Y 3/2) moist; common fine and medium distinct dark yellowish brown (10YR 4/6) moist, relict mottles; massive; hard, friable, slightly sticky and slightly plastic; few fine roots; common fine seams and masses of calcium carbonate; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Sheridan County, Wyoming; Murphy Gulch area; 1020 feet north and 980 feet west of the southeast corner of sec. 3, T. 54 N., R. 83 W. Buffalo Run Creek, Wyo. Quadrangle, 44 degrees 40 minutes 34 seconds north latitude and 106 degrees 50 minutes 49 seconds west longitude.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 7 to 20 inches thick. The mean annual soil temperature ranges from 47 to 53 degrees F. The soil temperature at a depth of 20 inches is 41 degrees or more for 145 to 192 days. The soils are moist in some or all parts of the moisture control section from April 15 to June 15 but are dry in all parts for 60 consecutive days following July 15 and 90 cumulative days from July 15 to October 25. The particle-size control section is loam or clay loam stratified with textures of loamy sand to silty clay loam. Clay ranges from 18 to 35 percent. Rock fragments average from 0 to 15 percent above 40 inches and are mainly pebbles. EC is less than 4 mmhos/cm throughout in the nonsaline phase. It ranges to 16 mmhos/cm in the saline phase.
The A horizon has hue of 10YR or 2.5Y, value of 3 to 5 dry, 2 or 3 moist, and chroma of 1 to 3. It is slightly alkaline or moderately alkaline.
The Bw and Bk horizons have hue of 10YR or 2.5Y, value of 3 to 6 dry, 3 to 5 moist, and chroma of 1 to 4. The Bw horizon is part of the mollic epipedon in some pedons. Calcium carbonate equivalent ranges from 4 to 15 percent. The horizons are slightly alkaline to strongly alkaline. The saline phase has visible salts or gypsum.
COMPETING SERIES: These are the Colombo and Nyswonger series (It is assumed these series are competing pending an update of the classification). These soils lack cambic horizons and have soil temperatures of 41 degrees F. or warmer for more than 192 days in most years. They also lack a consistent horizon of carbonate accumulation.
GEOGRAPHIC SETTING: Coaliams soils are on flood plains and low stream terraces. They formed in medium textured alluvium from mixed sources. Slopes are 0 to 6 percent. Elevations are 3,500 to 5,400 feet. The mean annual precipitation is about 17 inches but ranges from 10 to 19 inches of which about half falls as rain or snow in April, May and early June. The frost-free season is estimated to range from 105 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boruff, Haverdad, Rockypoint and Worthenton series. Boruff soils are poorly and somewhat poorly drained. Haverdad and Rockypoint soils do not have a mollic epipedon. Worthenton soils have an argillic horizon with over 35 percent clay in the particle-size control section.
DRAINAGE AND PERMEABILITY: Well and moderately well drained; slow to medium runoff; moderate permeability. A fluctuating water table is common below 40 inches in the spring and early summer. In some places it remains through October due to irrigation. These soils are subject to rare to frequent flooding for very brief or brief periods during spring runoff and prolonged high intensity storms in the spring and early summer. Depth to a wet soil moisture state in the moderately well drained phase is 3 to 6 feet at some time during the period of April through October.
USE AND VEGETATION: Rangeland, wildlife habitat, and some irrigated pasture. Native vegetation is basin wildrye, green needlegrass, and rhizomatous wheatgrass with an overstory of cottonwood.
DISTRIBUTION AND EXTENT: North central and eastern Wyoming. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Sheridan County, Wyoming; 1987.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 8 inches (Ap)
Torrifluventic subgroup - irregular decrease in organic carbon with depth.
MLRR- G
SIR's- WY0757, WY0979, WY1272