LOCATION SMILO NMEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, frigid Aridic Argiustolls
TYPICAL PEDON: Smilo cobbly sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; brown (10YR 4/3) cobbly sandy loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; common fine and very fine roots; few fine vesicular pores; 10 percent pebbles, 15 percent cobbles; moderately acid (pH 6.0); clear smooth boundary. (2 to 4 inches thick)
Bt1--2 to 8 inches; brown (10YR 4/3) loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; few fine tubular pores; few thin clay films lining pores and on faces of peds; neutral (pH 7.0); clear smooth boundary. (5 to 9 inches thick)
Bt2--8 to 15 inches; dark yellowish brown (10YR 3/4) cobbly clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine blocky structure; very hard, firm, sticky and plastic; few fine and common very fine roots; common fine tubular pores; moderately thick clay films lining pores and on faces of peds; 10 percent pebbles, 15 percent cobbles, 5 percent stones; neutral (pH 6.6); clear smooth boundary. (5 to 10 inches thick)
Bt3--15 to 25 inches; brown (7.5YR 4/4) very cobbly clay, brown (7.5YR 4/2) moist; moderate medium blocky structure; very hard, firm, sticky and plastic; few fine and common very fine roots; moderately thick clay films lining pores and on faces of peds; 10 percent pebbles, 20 percent cobbles, 5 percent stones; neutral (pH 6.8); clear smooth boundary. (8 to 13 inches thick)
C--25 to 32 inches; brown (7.5YR 4/4) gravelly clay, brown (7.5YR 4/2) moist; massive; very hard, firm, sticky and plastic; few very fine roots; 15 percent pebbles; neutral (pH 7.0); abrupt irregular boundary. (0 to 10 inches thick)
R--32 inches; basalt, lava flow.
TYPE LOCATION: Northern Catron County, New Mexico; southeast 1/2 southwest 1/4, sec. 10, T. 3 S., R. 13 W.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section December through April and July through September. The soil is driest during May and June. Aridic ustic moisture regime.
Soil Temperature: 44 to 47 degrees F.
Depth to bedrock: 20 to 40 inches
Particle-size control section:
Rock fragments - 10 to 30, dominantly, cobbles on a weighted average
Clay: 35 to 55 on a weighted average
Sand: less than 35 percent
A horizon:
Hue - 5YR, 7.5YR or 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 to 3
Bt horizon:
Hue - 5YR, 7.5YR or 10YR
Value: 3 to 5 dry, 3 to 7 moist
Chroma: 1 to 6
C horizon:
Hue - 5YR, 7.5YR or 10YR
Value: 4 to 8 dry, 2 to 7 moist
Chroma: 2 to 6
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: These soils formed from local alluvium derived dominantly from basalt flows. Elevations are 7,400 to 8,700 feet. Slopes range from 0 to 15 percent. The average annual precipitation is about 14 to 18 inches, and the mean annual temperature is about 43 to 45 degrees F. The frost-free period is about 80 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These soils are Adobe, Barela and Raton. The Adobe and Raton soils are less than 20 inches to a lithic contact. Barela soils are greater than 40 inches to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff. Slowly permeable.
USE AND VEGETATION: Areas of this soil are used mainly for grazing. Present vegetation includes blue grama, muhly species, muttongrass, threeawn, bottlebrush squirreltail, and trailing daisy, Apache plume, and rubber rabbitbrush. Scattered oneseed juniper and a few pinyon pine are on the steeper slopes.
DISTRIBUTION AND EXTENT: Western New Mexico, Catron County. These soils are moderately extensive. MLRA 39.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Catron County, New Mexico, 1982.
REMARKS: In October 2000, taxonomic classification was converted to the closest match found in Soil Taxonomy, Second Edition 1999. Some update was made to horizon nomenclature, competing series section, etc. Other placements may be more appropriate after a complete update.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: The zone from 0 to 8 inches.
Argillic horizon: The zone from 2 to 25 inches.