LOCATION MONOGRAM COEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Ustic Calciargids
TYPICAL PEDON: Monogram loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 1 inch; reddish brown (5YR 5/4) loam, reddish brown (5YR 4/3) moist; weak fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; neutral (pH 7.0); clear smooth boundary. (0 to 2 inches thick)
A2--1 to 3 inches; reddish brown (5YR 5/4) loam, dark reddish brown (5YR 3/4) moist; moderate fine granular structure; slightly hard, very friable, plastic; neutral (pH 7.2); clear smooth boundary. (2 to 6 inches thick)
BA--3 to 7 inches; light reddish brown (5YR 6/4) loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; mildly alkaline (pH 7.4); clear smooth boundary. (3 to 6 inches thick)
Bt--7 to 14 inches; reddish brown (5YR 5/4) loam, reddish brown (5YR 4/4) moist; strong medium subangular blocky structure; extremely hard, firm, sticky and plastic; mildly alkaline (pH 7.4); clear wavy boundary. (6 to 10 inches thick)
Btk--14 to 20 inches; reddish brown (5YR 5/4) clay loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; extremely hard, firm, slightly sticky and plastic; lime segregated in common irregular medium sized concretions; strongly effervescent (4 percent calcium carbonate); moderately alkaline (pH 8.0); clear wavy boundary. (4 to 8 inches thick)
Bk1--20 to 28 inches; pink (5YR 7/3) loam, reddish brown (5YR 5/4) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and plastic; many cicada casts; lime disseminated; violently effervescent (44 percent calcium carbonate); moderately alkaline (pH 8.0); clear wavy boundary. (6 to 10 inches thick)
2Bk2--28 to 42 inches; pinkish white (5YR 8/2) sandy clay loam, pink (5YR 7/4) moist; massive; hard, friable, slightly sticky and slightly plastic; lime disseminated; violently effervescent (70 percent calcium carbonate equivalent); moderately alkaline (pH 8.2); clear wavy boundary.
2Bk3--42 to 52 inches; pink (7.5YR 7/4) clay loam, light brown (7.5YR 6/4) moist; massive; hard, friable, slightly sticky and slightly plastic; lime disseminated; violently effervescent (44 percent calcium carbonate); moderately alkaline (pH 8.2); clear wavy boundary.
2Bk4--52 to 66 inches; light brown (7.5YR 6/4) sandy clay loam, brown (7.5YR 5/4) moist; massive; hard, friable, slightly sticky and plastic; lime disseminated; strongly effervescent (23 percent calcium carbonate); moderately alkaline (pH 8.4); abrupt wavy boundary.
R--66 inches; hard sandstone.
TYPE LOCATION: Montrose County, Colorado; 9 miles east, 10 miles south of Paradox, Colorado; 1,624 feet east and 1,624 feet south of the northwest corner, sec. 30, T. 46 N., R. 17 W.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 47 to 51 degrees F, and mean summer soil temperature ranges from 62 to 64 degrees F. Depth to calcareous material ranges from 6 to 26 inches. Coarse fragments range from 0 to 10 percent by volume throughout the particle-size control section and upper part of the C horizon and are small pebbles. Depth to the base of the argillic horizon ranges from 15 to 30 inches. The solum with the Bk horizon ranges from 22 to 40 inches thick.
The A horizon has hue of 5YR or 7.5YR, value of 4 and 5 dry, 3 or 4 moist, and chroma of 3 or 4.
The BA horizon has hue of 5YR through 7.5YR, value of 4 to 6 dry, 3 or 4 moist, and chroma of 4 to 6.
The Bt horizon has hue of 2.5YR through 7.5YR, value of 4 to 6 dry, 3 or 4 moist, and chroma of 4 to 6. Clay ranges from 18 to 35 percent and silt from 40 to 75 percent with a high fraction of coarse silt or very fine sand. It has less than 15 percent fine sand and coarser.
The Bk and 2Bk horizons have hue of 5YR or 7.5YR, value of 5 to 8 dry, 5 to 7 moist, and chroma of 2 to 6. They are clay loam or sandy clay loam with more than 15 percent coarser than very fine sand. The calcium carbonate equivalent of the calcic horizon ranges from 40 to 70 percent.
COMPETING SERIES: These are the Buick, Cahona, Keiser, Nepesta, Pulpit, Roubideau, Sharps, Tensleep, Verde, Villegreen, Wiley, and Witt soils. Pulpit, Roubideau, Sharps, Verde, and Villegreen soils have a lithic or paralithic contact above 40 inches. Buick soils have polygenetic profiles and lack a calcic horizon. Nepesta soils have 10 to 20 inches thick Ap horizons high in phosphate and nitrogen and border anthrorpic and mollic epipedons. Witt soils have a solum 30 inches or more thick. Cahona, Keiser, Tensleep, and Wiley soils lack a calcic horizon.
GEOGRAPHIC SETTING: Monogram soils are on mesas and benches. Elevation ranges from 6,800 to 7,300 feet. Slopes range from 1 to 8 percent. The soils formed in eolian material over sandstone. The mean annual precipitation ranges from 13 to 15 inches with nearly equal monthly distribution throughout the year. The mean annual temperature ranges from 45 to 49 degrees F. The frost-free season is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bond and Progresso soils. Bond soils have a lithic contact above 20 inches and are on warmer slopes and/or lower positions. Progresso soils have more than 15 percent sand coarser than very fine sand in their particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used principally as rangeland. Native vegetation is mainly big sagebrush and native grasses.
DISTRIBUTION AND EXTENT: Plateau areas in the San Miguel Basin area of southwestern Colorado. The soils of this series are of moderate extent with over 11,000 acres in this soil survey area.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Montrose County (San Miguel Area), Colorado, 1987.
REMARKS: This soil was sampled by the NSSL in 1980 for characterizations. Laboratory sample no. is S80CO-085-001.