LOCATION CROTALUS NMEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, carbonatic, thermic Ustic Haplocalcids
TYPICAL PEDON: Crotalus extremely gravelly loam, rangeland (colors are for dry soil unless otherwise noted).
A--0 to 2 inches; brown (7.5YR 5/4) crushed, extremely gravelly loam, dark brown (7.5YR 3/4) crushed, moist; 22 percent clay; weak fine granular structure; loose; slightly sticky and slightly plastic; few fine roots throughout; 40 percent gravels, 15 percent cobbles and 15 percent stones; strongly effervescent by HCl, 1 normal; slightly alkaline, pH 7.8, pH meter 1:1 water; gradual smooth boundary (1 to 4 inches thick).
Bk1--2 to 8 inches; brown (7.5YR 4/4) crushed, very cobbly loam, dark brown (7.5YR 3/4) crushed, moist; 25 percent clay; moderate fine subangular blocky structure; slightly hard, friable; moderately sticky and moderately plastic; few fine roots throughout; few fine dendritic tubular pores, 5 percent fine spherical carbonate masses on faces of peds; 20 percent nonflat subrounded indurated 0.1- to 3-inch tuff gravel and 15 percent nonflat subrounded indurated 3- to 10-inch tuff cobbles; strongly effervescent by HCl, 1 normal; slightly alkaline, pH 7.8, pH meter 1:1 water;; gradual wavy boundary (4 to 10 inches thick).
Bk2--8 to 27 inches; brown (7.5YR 5/4) crushed, extremely gravelly loam, brown (7.5YR 4/4) crushed, moist; 27 percent clay; moderate fine subangular blocky structure; slightly hard, friable; moderately sticky and moderately plastic; few fine roots throughout; few fine dendritic tubular pores; 10 percent fine irregular carbonate masses on faces of peds; 40 percent nonflat subrounded indurated 0.1- to 3-inch tuff gravel, 15 percent nonflat subrounded indurated 3- to 10-inch tuff cobbles and 10 percent nonflat subrounded indurated 10- to 24-inch tuff stones; strongly effervescent by HCl, 1 normal; slightly alkaline, pH 7.7, pH meter 1:1 water;; clear wavy boundary (15 to 25 inches thick).
Bk3--27 to 45 inches; pink (7.5YR 8/3) crushed, extremely gravelly clay loam, light brown (7.5YR 6/4) crushed, moist; 28 percent clay; moderate medium subangular blocky structure; slightly hard, friable; moderately sticky and moderately plastic; very few fine roots throughout; few fine dendritic tubular pores; 100 percent coarse irregular carbonate masses in matrix; 40 percent nonflat subrounded indurated 0.1- to 3-inch tuff gravel and 20 percent nonflat subrounded indurated 3- to 10-inch tuff cobbles; violently effervescent by HCl, 1 normal; slightly alkaline, pH 7.8, pH meter 1:1 water;; gradual wavy boundary (12 to 25 inches thick).
Bk4--45 to 80 inches; pink (7.5YR 7/3) crushed, extremely gravelly clay loam, light brown (7.5YR 6/4) crushed, moist; 32 percent clay; weak fine subangular blocky structure; slightly hard, friable; slightly sticky and slightly plastic; very few fine roots throughout; 40 percent medium irregular carbonate masses on faces of peds; 60 percent nonflat subrounded indurated 0.1- to 3 inch tuff gravel and 15 percent nonflat subrounded indurated 3- to 10-inch tuff cobbles; violently effervescent by HCl, 1 normal; slightly alkaline, pH 7.6, pH meter 1:1 water.
TYPE LOCATION: Dona Ana County, New Mexico; approximately 5.1 miles W. and 9.8 miles S. of White Sands, 220 feet west and 190 feet north of the SE corner of S. 7, T. 24 S., R. 4 E. USGS Bishop Cap topographic quadrangle; lat. 32 degrees, 13 minutes, 6.96 seconds N. and long. 106 degrees 33 minutes 8.46 seconds W. UTM zone 13S, 352621E, 3566750N; NAD 27.
RANGE IN CHARACTERISTICS:
Soil Moisture: An aridic moisture regime bordering on ustic. The moisture control section is usually dry in all parts less than three-fourths of the time that the soil temperature exceeds 41 degrees F. Ustic aridic moisture regime.
Mean annual soil temperature - 61 to 65 degrees F.
Depth to calcic horizon - 20 to 35 inches
Particle-size control section (weighted average):
Clay content: 25 to 35 percent
Coarse fragment content: 60 to 75 percent
Reaction: slightly alkaline to moderately alkaline
Calcium carbonate equivalent: 40 to 55 percent (less than 20mm fraction)
A horizon
Hue: 5YR, 7.5YR
Value: 4 or 5 dry, 3 to 5 moist
Chroma: 4 or 6, dry or moist
Coarse fragments: tuff fragments; 35 to 65 percent gravel; 5 to 15 percent cobbles; 5 to 15 percent stones
Bk horizons
Hue: 5YR, 7.5YR
Value: 4 to 8 dry, 4 to 6 moist
Chroma: 3 or 4, dry or moist
Texture modifier: very gravelly or extremely gravelly
Coarse fragments: 60 to 85 percent total coarse fragments; 50 to 70 percent gravel; 10 to 25 percent cobbles; 0 to 10 percent stones.
Texture: loam, clay loam
COMPETING SERIES: These are the
Bankston (NM),
Bascal (NM),
Bascom (NM),
Cienega (TX) and the
Mule (AZ) soils. The Bankston soil is moderately deep to bedrock. The Bankston soil contains 10 to 18 percent clay in the particle size control section. The Bascal soils have 5YR hue and discontinuities below 30 inches.
Bascom soils formed in Jurassic and Triassic redbed material and are in the Pecos-Canadian
Plains and Valleys and are more moist in
May and June in the soil moisture control section. Mule and Cienega soils have 35 to 60 percent rock fragments in the particle size control section. The Cienega soils are derived from limestone and have calcic horizon at depth of 10 to 20 inches. The Mule soils contain 5 to 18 percent clay in the particle size control section.
GEOGRAPHIC SETTING:
Parent material: Colluvium from tuff modified by eolian material
Landform: Mountain flanks and bases
Slope: 15 to 35 percent
Mean annual air temperature: 60 to 64 degrees F.
Mean annual precipitation: 10 to 12 inches
Precipitation pattern: Precipitation falls mostly during the months of July through September. The driest months are March and April. Precipitation during the months of January, February, and March is less than 13 percent of the total.
Frost-free period: 170 to 210 days
Elevation: 4,000 to 5,300 feet
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Brewster and
Sotol series.
Brewster soils are less than 20 inches to bedrock and are on mountain tops and flanks.
Sotol soils have a clayey-skeletal control section and are on mountain flanks and bases.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderately slow. Runoff is high on slopes of 15 to 20 percent and very high on slopes greater than 20 percent.
USE AND VEGETATION: Used for livestock grazing. Vegetation is of the desert grassland type consisting of black grama, sideoats grama, tridens spp., ocotillo, mesquite, and mariola.
DISTRIBUTION AND EXTENT: Southern New Mexico; LRR D, MLRA 42. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES ESTABLISHED: Dona Ana County, New Mexico; 2001.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle size control section: the zone from 10 to 40 inches (Bk2 and Bk3)
Ochric epipedon: the zone from 0 to 7 inches (A and Bk1 horizons)
Calcic horizon: the zone from 27 to 60 inches (Bk3 and Bk4 horizons)
Ustic feature: soil has aridic moisture that borders on the ustic moisture regime.
The assignment of the cation exchange capacity is inferred from lab data from similar soils in the surrounding area.
Updated competing series section 3/17/08, CEM