LOCATION DES MOINES NM+UTEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Pachic Argiustolls
TYPICAL PEDON: Des Moines cobbly silt loam, forested. (Colors are for air dry soil unless otherwise noted.)
A--0 to 4 inches; very dark grayish brown (10YR 3/2) cobbly silt loam, black (10YR 2/1) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many fine roots; 15 percent cobbles and gravel, 5 percent stones; neutral; clear smooth boundary. (4 to 18 inches thick)
BA--4 to 18 inches; very dark grayish brown (10YR 3/2) very cobbly silty clay loam, very dark gray (10YR 3/1) moist; moderate fine subangular blocky structure; hard, very friable, sticky and plastic; many fine and very fine roots; 50 percent cobbles and gravel, 10 percent stones; neutral; abrupt irregular boundary. (4 to 16 inches thick)
Bt--18 to 36 inches; dark grayish brown (10YR 4/2) very stony silty clay, very dark grayish brown (10YR 3/2) moist; strong fine subangular and angular blocky structure; very hard, firm, sticky and plastic; few fine and very fine roots; many prominent clay films on faces of peds; 30 percent cobbles and gravel and 30 percent stones; neutral; abrupt irregular boundary. (13 to 40 inches thick)
BC--36 to 60 inches; light yellowish brown (10YR 6/4) extremely stony sandy clay loam, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; 50 percent stones and boulders and 40 percent cobbles and gravel; slightly effervescent; slightly alkaline.
TYPE LOCATION: Union County, New Mexico; 2,300 feet north and 700 feet east of the SW corner of sec. 30, T.29N., R.29E.
RANGE IN CHARACTERISTICS:
Soil moisture: ustic moisture regime bordering on aridic. Moist intermittently April through August. Driest December through February.
Mean annual soil temperature; 42 to 47 degrees F.
Mean summer soil temperature: 59 to 64 degrees F.
Thickness of the A and Bt horizons: 24 to 60 inches thick
Depth to lithic contact: 40 to 80 inches.
The surface has 15 to 75 percent igneous cobbles, stones or boulders.
Depth to free calcium carbonate: 30 to 60 inches and is slightly effervescent
Reaction: neutral or slightly alkaline.
Some pedons have an organic surface horizon up to 3 inches thick.
A horizon
Hue: 7.5YR or 10YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 or 2
Texture of the fine earth fraction: silt loam or silty clay loam
Rock fragment content: 15 to 75 percent that range in size from gravel to boulders. About 10 to 40 percent of the rock fragments are gravel.
The Bt horizon
Hue: 7.5YR or 10YR
Value: 3 to 6 dry, 2 to 4 moist
Chroma: 1 to 4
Texture of the fine earth fraction: silty clay loam, silty clay or clay
Rock fragment content: 35 to 80 percent ranging from gravel to stones or boulders. About 10 to 40 percent of the rock fragments are gravel. Some of the rock fragments are partially decomposed and have clay films within the rock structure.
The BC horizon (or C horizon, where present)
Rock fragment content: 70 to 95 percent
Texture of the fine earth fraction: sandy loam or sandy clay loam.
COMPETING SERIES: These are the
Dalcan (UT),
Godding (CO),
Golime (CO), and
Gordonpoint (UT).
Dalcan soils: have a lithic contact at depths of 20 to 40 inches.
Godding soils: are dry June 1 to July 15.
Golime soils: have identifiable secondary carbonates in the solum at depths of 24 to 40 inches. In addition, Golime soils have a calcic horizon.
Gordonpoint soils: have a combined thickness of A and Bt horizons of greater than 60 inches.
GEOGRAPHIC SETTING:
Landform: moderately steep to very steep mountain sideslopes
Elevation: 7,000 to 8,200 feet
Slope: 0 to 70 percent
Parent material: colluvium and alluvium over bedrock with solid rock at depths of 40 to 80 inches.
Mean annual temperature: 42 to 46 degrees F.
Mean annual precipitation: 18 to 22 inches, most of which occurs from April through August.
Frost-free period: 70 to 140 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Dalcan soils and the
Fallsam and
Sinnigam series.
Fallsam soils: have mesic temperature regime.
Sinnigam soils: have a lithic contact at depths of 10 to 20 inches.
DRAINAGE AND PERMEABILITY: Well-drained; runoff is medium on slopes less than 1 percent, high on 1 to 5 percent slopes, and very high on slopes greater than 5 percent. slow permeability.
USE AND VEGETATION: These soils are used for rangeland with most grazing during the summer months. The soils are also a wildlife habitat for deer and turkey. The vegetation is mountain muhly, Arizona fescue, little bluestem, bluegrass, blue grama with an overstory of juniper, pinyon, ponderosa pine, Gambel's oak, and some scattered spruce and fir.
DISTRIBUTION AND EXTENT: Northeastern New Mexico. LRR E and G, MLRA70. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Union County, New Mexico, 1972.
REMARKS: This revision reclassifies the series from Pachic Argiboraolls frigid Pachic Argiustolls.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 36 inches. (A, BA, and Bt horizons)
Argillic horizon: 18 to 36 inches. (Bt horizon)
Taxonomic Version: Second Edition, 1999
ADDITIONAL DATA: None