LOCATION TORREON NM+COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Calcidic Argiustolls
TYPICAL PEDON: Torreon silt loam - rangeland. (Colors are for air dry soil unless otherwise noted.)
A--0 to 6 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; many very fine interstitial pores; neutral; clear boundary. (2 to 7 inches thick)
BA--6 to 11 inches; brown (10YR 4/3) silty clay loam, dark brown (10YR 3/3) moist; moderate fine prismatic structure parting to moderate fine subangular blocks; hard, firm, slightly sticky and plastic; many fine roots; common very fine tubular pores; neutral; clear smooth boundary. (0 to 10 inches thick)
Bt--11 to 21 inches; brown (10YR 5/3) clay, brown (10YR 4/3) moist; moderate medium prismatic structure parting to fine and medium blocks; very hard, very firm, very sticky and very plastic; common fine roots; common very fine tubular pores; common continuous distinct clay films on faces of peds and in pores; slightly effervescent; slightly alkaline; clear smooth boundary. (10 to 21 inches thick)
Btk--21 to 36 inches; pale brown (10YR 6/3) silty clay, brown (10YR 5/3) moist; moderate medium prismatic structure parting to moderate fine and medium angular blocks; very hard, firm, very sticky and very plastic; few fine roots; common very fine tubular pores; many continuous distinct clay films on faces of peds and in pores; common fine and medium masses and threads of calcium carbonate; strongly effervescent; moderately alkaline; clear smooth boundary. (8 to 22 inches thick)
Bk1--36 to 52 inches; pale brown (10YR 6/3) silty clay loam, yellowish brown (10YR 5/4) moist; weak fine prismatic structure; hard, friable, sticky and plastic; very few fine roots; common very fine tubular pores; 5 percent basalt pebbles; common medium masses and threads of calcium carbonate; violently effervescent; moderately alkaline; clear smooth boundary.
Bk2--52 to 62 inches; very pale brown (10YR 8/2) clay loam, very pale brown (10YR 7/3) moist; massive; soft, friable, sticky and plastic; 10 percent basalt gravel, cobbles and stones; violently effervescent; moderately alkaline.
TYPE LOCATION: Colfax County, New Mexico; about 5.5 miles east and 15 miles south of Raton, New Mexico; 700 feet south, 2100 feet west of the northeast corner of section 25, T. 29 N., R. 24 E.; Tinaja Mountain USGS quad; latitude 36 degrees, 43 minutes, 27 seconds N. and longitude 104 degrees, 20 minutes, 21 seconds W.; NAD 1927.
RANGE IN CHARACTERISTICS:
Soil moisture: moist in some part May through August. Ustic moisture regime bordering on aridic.
Depth to lithic contact: greater than 60 inches.
Depth to calcic horizon: 27 to 40 inches.
The thickness of the argillic horizons: 18 to 43 inches.
Thickness of the mollic epipedon: 10 to 20 inches.
Linear extensibility: exceeds 6.0 percent.
Particle size control section: weighted average:
Clay content: 40 to 50 percent
Rock fragment content: 0 to 20 percent by volume.
The A horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 2 moist
Chroma: 2 to 4.
Reaction: neutral or slightly acid
SAR: 0 to 2
The Bt horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 2 to 6
Texture: silty clay loam, clay, and silty clay
Clay content: 35 to 55 percent
SAR: 0 to 4
Reaction: neutral to moderately alkaline
The upper part of the Bt horizon is generally noncalcareous.
The Btk horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 6
Texture: clay, silty clay loam, and silty clay
Clay content: 35 to 55 percent
SAR: 2 to 6
Rock fragment content: 0 to 15 percent
Reaction: slightly alkaline to strongly alkaline
Calcium carbonate equivalent: 5 to 25 percent
The Bk horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 6
Texture of the fine earth fraction: silty clay loam, clay loam
Clay content: 30 to 40 percent
SAR: 2 to 8
Rock fragment content: 5 to 35 percent basalt gravel and cobbles, increasing with depth
Reaction: moderately alkaline or strongly alkaline
Calcium carbonate equivalent: 15 to 40 percent
COMPETING SERIES: These are the Denver (CO), Englewood (CO), Kutch (CO) and Pleasant (CO) series. A closely similar soil is the La Brier series (NM).
Denver soils: does not have a calcic horizon.
Englewood and
Pleasant soils: have a mollic epipedon thicker than 20 inches.
Kutch soils: have a paralithic contact between 20 and 40 inches of the surface.
La Brier soils: have a mollic epipedon greater than 30 inches and do not have a calcic horizon.
GEOGRAPHIC SETTING:
Landform: nearly level to gently sloping basalt-capped mesas, lava plateaus, terraces, and fans.
Parent material: residuum and alluvium derived principally from basalt but slightly modified by eolian sediments.
Slopes: 0 to 20 percent.
Elevation: 5,000 to 7,500 feet.
Mean annual precipitation: 14 to 17 inches.
Mean annual temperature is 45 to 53 degrees F., and the annual summer temperature is 68 to 72 degrees F.
The Thornthwaite P-E index ranges from 20 to 40.
Frost-free period: 100 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Apache,
Ayon,
Capulin,
Deacon,
La Brier, and
Thunderbird soils.
Apache soils have a lithic contact at depths of less than 20 inches.
Ayon soils: have a loamy-skeletal control section.
Capulin soils: have a fine-loamy control section.
Deacon soils: do not have an argillic horizon.
La Brier soils: have vertic properties.
Thunderbird soils: have a lithic contact at depths of 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; slow permeability.
USE AND VEGETATION: Rangeland is the principal use. Vegetation is blue grama, ring muhly, western wheatgrass, sideoats grama, snakeweed, and few widely spaced pinyon, juniper, and ponderosa pine trees.
DISTRIBUTION AND EXTENT: Northern New Mexico and southeastern Colorado. LRR G, MLRA 70. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Union County, New Mexico, 1972.
REMARKS: This update changes the classification from Aridic Argiustolls to Torrertic Argiustolls based on laboratory data from Las Animas County, Colorado. This update also moves the type location to Colfax County, New Mexico and is representative of northeastern New Mexico and southeastern Colorado.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 11 inches. (A and AB horizons)
Argillic horizon: 11 to 36 inches. (Bt and Btk horizons)
Calcic horizon: 36 to 60 inches thick. (BCk horizon)
Torrertic feature: Linear extensibility exceeds 6.0 cm between the mineral soil surface and 100 cm.
ADDITIONAL DATA: Laboratory number: S87CO-071-004