LOCATION RATON NM COEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Lithic Argiustolls
TYPICAL PEDON: Raton stony silt loam, rangeland. (Colors are for dry soil unless otherwise noted.)
Al--0 to 5 inches; very dark grayish brown (10YR 3/2) very stony silt loam, very dark brown (10YR 2/2) moist; moderate very fine granular structure; soft, friable, slightly sticky and slightly plastic; many fine and very fine roots; 40 percent basalt stones, cobbles and boulders and 5 percent gravel; neutral (pH 6.6); abrupt smooth boundary.
A2--5 to 9 inches; very dark grayish brown (10YR 3/2) very stony silt loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure parting to moderate very fine granules; slightly hard friable, slightly sticky and slightly plastic; common fine and very fine roots; few fine tubular pores; 45 percent basalt stones, cobbles and boulders and 5 percent gravel; neutral (pH 6.6); clear smooth boundary. (Combined thickness of the A1 and A2 horizons is 4 to 12 inches)
Bt--9 to 15 inches; brown (7.5YR 4/2) extremely stony clay, dark brown (7.5YR 3/2) moist; moderate medium subangular blocky structure; very hard, very firm, stocky and very plastic; few fine and very fine roots; few fine tubular pores; many moderately thick clay films on faces of peds; 55 percent basalt stones, cobbles and boulders and 10 percent gravel; neutral (pH 7.0); abrupt wavy boundary. (2 to 11 inches thick)
R--15 inches; hard basalt.
TYPE LOCATION: Colfax County, New Mexico; about 9 miles northwest of Capulin; 310 feet north, 465 feet west of SE corner of section 26, T.30N., R.26E. Johnson Park USGS quad; approximate lat. 36 degrees 47 minutes 59 seconds N. and long. 104 degrees 8 minutes 8 seconds W., NAD 83
RANGE IN CHARACTERISTICS:
Soil moisture: The SMCS is usually moist, in some part, for more than 90 cumulative days from May through October. It is usually dry, in all parts, for less than 90 cumulative days during the same period. It is continuously moist in some part November through April. The period of maximum precipitation is July through October. Typic ustic moisture regime.
Mean annual soil temperature - 42 to 44 degrees.
Reaction - neutral
Depth to bedrock, and thickness of the mollic epipedon - 6 to 20 inches.
Rock fragments - 5 to 15 percent gravel
35 to 65 percent stones, cobbles, boulders.
A horizon:
Hue: 7.5YR or 10YR
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 1 through 3 dry and 1 or 2 moist.
Texture of the fine earth fraction: silt loam, clay loam or loam
Rock fragment content: 25 to 50 percent
AB horizon is present in some pedons.
Bt horizon:
Hue: 10YR, 7.5YR, or 5YR.
Value: 4 or 5 dry, 2 through 4 moist.
Chroma: 1 through 3 dry and 2 through 4 moist.
Texture of the fine earth fraction: clay, silty clay, clay loam or silty clay loam
Clay content: 35 to 55 percent
Rock fragment content: 35 to 65 percent
COMPETING SERIES: These are
Ernem (MT) and
Posant (CO) series.
Ernem soils: slightly or moderately alkaline and are over sandstone.
Posant soils: have mainly gravel size rock fragments and are over quartz latite.
GEOGRAPHIC SETTING:
Landform: Plateaus, basalt capped mesas, ridges and hills
Parent material: colluvium and residuum weathered mainly from basalt with some influence from ash, cinders, and other volcanic debris.
Elevation: 7,000 to 9,000 feet.
Slope: 1 to 25 percent but range to 60 percent.
Mean annual precipitation: 15 to 20 inches, but ranges to 24 inches in some areas.
Mean annual temperature: 42 to 44 degrees F.
Frost-free period: 80 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Barela, Burnac, Hillery and Yankee soils and the competing Dalcan soils. Barela, Hillery and Yankee soils do not have a lithic contact above depth of 40 inches. Burnac soils have lithic contacts at depths of 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; slow permeability.
USE AND VEGETATION: Native rangeland and wildlife habitat. Gentle to moderate slopes have blue grama, Arizona fescue, western wheatgrass, big bluestem, little bluestem, mountain muhly and Gambel's oak with widely scattered ponderosa pine. Strongly sloping to steep sides of volcanic cones have ponderosa pine, Rocky Mountain juniper and pinyon pine.
DISTRIBUTION AND EXTENT: Northeastern New Mexico and southeastern Colorado. LRR E, MLRA 48A and 49. This soil is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Union County, New Mexico 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 15 inches (A and B horizons)
Argillic horizon - the zone from 9 to 15 inches. (Bt horizon)
Lithic contact - at 15 inches
The statement in the RIC indicating the soil is dry in May and June has been removed. This series was established in Colfax County, New Mexico in an area that is typically continental climate with peak moisture from April through August and driest December and January. This change moves the moisture pattern to the original concept of the series.
Taxonomic Version: Tenth Edition, 2006