LOCATION ROMBO NM COEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, frigid Typic Haplustepts
TYPICAL PEDON: Rombo cobbly silty clay loam--rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; grayish brown (2.5Y 5/2) cobbly silty clay loam, very dark grayish brown (2.5Y 3/2) moist; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine, medium and coarse roots; few fine pores; 15 percent angular gravel, cobbles, and stones; slightly alkaline; clear wavy boundary. (2 to 4 inches thick)
Bw--3 to 20 inches; grayish brown (2.5Y 5/2) cobbly silty clay loam, dark grayish brown (2.5Y 4/2) moist; weak coarse subangular blocky structure; very hard, very firm, moderately sticky and moderately plastic; common fine, medium and coarse roots; few fine pores; 25 percent angular gravel and cobbles; slightly alkaline; clear wavy boundary. (12 to 20 inches thick)
Bk--20 to 30 inches; grayish brown (2.5Y 5/2) cobbly clay, dark grayish brown (2.5Y 4/2) moist; massive; very hard, very firm, moderately sticky and very plastic; few fine roots; few fine pores; 25 percent angular gravel and cobbles; strongly effervescent; common masses and coatings of lime on undersides of coarse fragments; slightly alkaline; clear wavy boundary. (6 to 16 inches thick)
2Cr--30 to 40 inches; soft shale with thin irregular bands of carbonaceous material.
TYPE LOCATION: Colfax County, New Mexico; about 12 miles west of Raton, New Mexico, 3.8 miles up Potato Canyon from the junction of Potato Canyon Road with Canadian River Road and 160 feet northwest up a south-facing slope from the junction of a small drainage from the northwest with the Potato Canyon drainage; latitude 36 degrees, 53 minutes, and 03 seconds N., longitude 104 degrees, 38 minutes, and 45 seconds W.;
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section in spring and summer. Ustic moisture regime, typic subclass.
Mean annual soil temperature: 43 to 47 degrees F.
Depth to paralithic contact: 20 to 40 inches
Rock fragment content: 15 to 50 percent on the surface, 10 to 30 percent on a weighted average in the particle-size control section.
Reaction: neutral or slightly alkaline
A horizon:
Hue: 2.5Y or 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 to 3
Texture: clay, silty clay loam, clay loam or loam.
Bw horizon:
Hue: 2.5Y or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 through 4
Texture: silty clay loam, clay loam, or clay
Clay content: 35 to 50 percent
Bk horizon:
Hue: 2.5Y or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 through 4
Texture: silty clay loam, clay loam, or clay
Calcium carbonate equivalent: 3 to 10 percent
COMPETING SERIES: This is the
Goemmer(CO) series.
Goemmer soils: have hues redder than 10YR and do not have horizons with calcium carbonate accumulations.
GEOGRAPHIC SETTING:
Landform: steep and very steep stony and bouldery convex mountain slopes and hills .
Parent material: stony colluvium and alluvium from shale; typically of the Raton Formation.
Elevations range from 7,000 to 9,000 feet.
Slopes: 3 to 60 percent
The climate is continental.
Mean annual temperature: 40 to 47 degrees F., and the mean summer temperature is 61 to 63 degrees F.
Mean annual precipitation: 16 to 23 inches
Frost free period: 70 to 100 days, 80 to 100 days in the Rio Arriba Area.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dargol and Midnight soils. Dargol soils have argillic horizons over bedrock at depths of 20 to 40 inches. Midnight soils have a loamy-skeletal control section.
DRAINAGE AND PERMEABILITY: Well drained, high or very high runoffhigh runoffvery high runoff; slow permeability.
USE AND VEGETATION: Wildlife, recreation, and limited use for range. Gambel's oak, mountain mahogany, twoneedle pinyon, oneseed juniper, blue grama, sideoats grama, little bluestem, and big bluestem.
DISTRIBUTION AND EXTENT: Northeastern New Mexico and southeastern Colorado. LRR E, MLRA's 48A and 49. This series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Colfax County, New Mexico, 1974.
REMARKS: Diagnostic horizons and features in this pedon are:
Particle-size control section: the zone from 10 to 30 inches. (Part of the Bw and Bk horizons)
Ochric epipedon: the zone from 0 to 3 inches. (A horizon)
Cambic horizon: the zone from 3 to 20 inches. (Bw horizon)
Paralithic contact: at 30 inches.(Cr horizon)
Changes to soil moisture in the range in characteristics reflects the climate of Colfax County, New Mexico.
Taxonomic Version: Tenth Edition, 2006