LOCATION AYON NMEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Aridic Calciustolls
TYPICAL PEDON: Ayon stony silt loam--grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 6 inches; dark grayish brown (10YR 4/2) stony silt loam, very dark brown (10YR 2/2) moist; moderate coarse granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and very fine roots; 30 percent rounded basalt stones, cobble, and pebbles; strongly effervescent; slightly alkaline (pH 7.5); clear smooth boundary. (3 to 20 inches thick)
Bw--6 to 17 inches; dark grayish brown (10YR 4/2) very stony loam, very dark brown (10YR 2/2) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and very fine roots; common fine tubular pores; 45 percent rounded basalt stones, cobbles, and pebbles; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (4 to 12 inches thick)
Bk1--17 to 31 inches; white (10YR 8/1) extremely stony sandy clay loam, light gray (10YR 7/2) moist; massive; hard, firm, slightly sticky and plastic; few fine and very fine roots; 65 percent rounded basalt stones, cobbles, and pebbles; rock fragments have calcium carbonate coatings and there are discontinuous layers of strongly cemented and indurated caliche; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (5 to 20 inches thick)
Bk2--31 to 60 inches; white (10YR 8/1) extremely stony loam, light gray (10YR 7/2) moist; massive; slightly hard, friable, slightly sticky and plastic; very few roots; 65 percent rounded basalt stones, cobbles, and pebbles; rock fragments have calcium carbonate coating; discontinuous layers of indurated caliche; violently effervescent; moderately alkaline (pH 8.0).
TYPE LOCATION: Colfax County, New Mexico; about 30 miles south, southeast, of Raton; 1,100 feet east and 740 feet south of the northwest corner of sec. 13, T. 26 N., R. 25 E.
RANGE IN CHARACTERISTICS:
Soil Moisture: Ustic moisture regime bordering on Aridic. Moist intermittently from May through August. Driest during October through April.
Soil Temperature: 50 to 57 degrees F.
Depth to calcic horizon: 10 to 40 inches
Particle size control section:
Clay content: 18 to 35 percent
Rock fragments: 35 to 80 percent, dominantly cobbles and stones.
A or Bw horizon
Hue: 10YR to 2.5Y
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 to 3
Texture of the fine earth fraction: loam or silt loam
Rock fragment content: 25 to 50 percent, dominantly stones and cobbles.
Reaction: slightly alkaline to strongly alkaline.
Bk horizon
Hue: 5YR to 10YR
Value: 6 to 8 dry, 5 to 7 moist
Chroma: 1 to 4
Texture of the fine earth fraction: sandy clay loam, silt loam, loam, or clay loam.
Reaction: moderately alkaline or strongly alkaline.
Calcium carbonate equivalent: 15 to 50 percent. Visible calcium carbonate in the form of coatings on rock fragments.
COMPETING SERIES: There are no competing series. Potential competitors were a superactive cation exchange activity class assigned are the Hogardero (NM), Mextank (AZ), Modyon (NM), and Pena (NM) series.
Hogardero soils: have a thin, partially cemented calcic horizon at depths of 10 to 20 inches.
Mextank soils: average less than 18 percent clay in the particle size control section and receive winter precipitation.
Modyon soils: have a lithic contact within 20 to 40 inches.
Pena soils: have coarse fragments dominantly consisting of caliche fragments, the majority of which are less than 10 inches in diameter.
GEOGRAPHIC SETTING:
Parent material: stony alluvium and colluvium
Landform: gently sloping to steep fans, terraces and valley side slopes on and around the edges of basalt flows.
Elevation: 5,000 to 7,500 feet.
Slope: 1 to 40 percent.
Mean annual precipitation: 14 to 17 inches.
Mean annual temperature: 48 to 55 degrees F.
Frost free period: 110 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Apache,
Capulin,
Fallsam,
Thunderbird, and
Torreon.
Apache soils: on basalt flows and have bedrock at less than 20 inches.
Capulin and Torreon soils: on fans below basalt flows and have an argillic horizon.
Thunderbird and Fallsam soils: have an argillic horizon and are over basalt flows.
DRAINAGE AND PERMEABILITY: Well drained; runoff is low on 2 to 5 percent slopes, medium on 5 to 10 percent slopes, high on 10 to 20 percent slopes, and very high on slopes greater than 20 percent; moderate permeability.
USE AND VEGETATION: These soils are used for grazing. The present vegetation consists of western wheatgrass, blue grama, bottlebrush squirreltail, muttongrass, sideoats grama and oakbrush.
DISTRIBUTION AND EXTENT: Northeastern New Mexico and southern Colorado. LRR G, MLRA 70; The series is extensive
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Union County, New Mexico, 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 17 inches. (A and Bw horizons)
Calcic horizon: 17 to 60 inches. (Bk1 and Bk2 horizons)
Remarks: "Intermittent soil moisture from May through August" was added to the Range in Characteristics to represent both Union and Colfax Counties and southeastern Colorado where the series was established.
Taxonomic Version: Second Edition, 1999