LOCATION ELDADO NMEstablished Series
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Ustic Calciargids
TYPICAL PEDON: Eldado gravelly fine sandy loam--in rangeland on a convex slope of 2 percent at an elevation of 6,780 feet. (Colors are for dry soils unless otherwise noted.)
A--0 to 2 inches; brown (10YR 5/3) gravelly fine sandy loam, brown (10YR 4/3) moist; moderate thin platy structure parting to weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; common fine irregular pores; 13 percent basalt gravel, 1 percent cobbles, and 1 percent basalt stones; slightly effervescent; neutral (pH 7.2); clear smooth boundary. (1 to 3 inches thick)
Btk1--2 to 9 inches; brown (7.5YR 5/4) sandy clay loam, brown (7.5YR 4/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; common fine irregular pores; many distinct clay films bridging sand grains and coating ped faces; 5 percent basalt gravel, 1 percent cobbles, and 1 percent basalt stones; calcium carbonate occurs as common very fine and fine soft masses and as coats on rock fragments; 6 percent calcium carbonate equivalent; slightly effervescent; slightly alkaline (pH 7.8); clear wavy boundary.
Btk2--9 to 13 inches; pale brown (10YR 6/3) sandy clay loam, brown (10YR 5/3) moist; moderate fine and medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and fine roots; common fine irregular pores; common distinct clay films bridging sand grains; 10 percent basalt gravel and 2 percent basalt cobbles; calcium carbonate is disseminated; 35 percent calcium carbonate equivalent; violently effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (The combined thickness of the Btk horizons is 8 to 15 inches.)
Bk1--13 to 25 inches; light gray (10YR 7/2) sandy clay loam, pale brown (10YR 6/3) moist; weak medium and coarse subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and fine roots; common fine irregular pores; 10 percent basalt gravel and 1 percent basalt cobbles; calcium carbonate is disseminated; 45 percent calcium carbonate equivalent; violently effervescent; strongly alkaline (pH 8.6); gradual wavy boundary. (0 to 16 inches thick)
2Bk2--25 to 43 inches; light brown (7.5YR 6/3) extremely gravelly loamy coarse sand, brown (7.5YR 5/3) moist; single grained; loose, loose, nonsticky and nonplastic; common very fine and fine roots; 55 percent basalt gravel, 15 percent basalt cobbles, and 5 percent basalt stones; calcium carbonate occurs as many very fine and fine soft masses and as coats on rock fragments; 5 percent calcium carbonate equivalent; strongly effervescent; strongly alkaline (pH 8.8); gradual wavy boundary. (26 to 90 inches thick)
2C--43 to 72 inches; light brown (7.5YR 6/3) extremely gravelly coarse sand, brown (7.5YR 5/3) moist; single grained; loose, loose, nonsticky and nonplastic; few very fine and fine roots; 60 percent basalt gravel, 5 percent basalt cobbles, and 1 percent basalt stones; noncalcareous; slightly alkaline (pH 7.6). (0 to 52 inches thick)
TYPE LOCATION: McKinley County, New Mexico; Mesa Cortada Quadrangle; about 2.3 miles east-southeast of Mesa Sarcio; 107 degrees 26 minutes 38 seconds west longitude, 35 degrees 32 minutes 00 seconds north latitude.
RANGE IN CHARACTERISTICS:
Soil Moisture: The SMCS is usually dry, in all parts, 105 to 160 cumulative days from April through October. It is usually moist, in some part, 50 to 105 cumulative days during the same period. It is intermittently moist in some part November through April. The period of maximum precipitation is July through October. The soil is driest during May and June. Ustic aridic moisture regime.
Soil Temperature: 51 to 56 degrees F
Particle size control section: 20 to 35 percent clay and less than 35 percent rock fragments in the upper part; and less than 10 percent clay and greater than 35 percent rock fragments in the lower part.
Depth to calcic horizon: 5 to 15 inches with 15 to 55 percent calcium carbonate equivalent
Depth to horizons with greater than 35 percent rock fragments: 10 to 30 inches
A horizon
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4 dry
Texture: fine sandy loam or loam
Rock fragments: mostly basalt with some sandstone; 10 to 40 percent total range; 10 to 40 percent gravel; 0 to 1 percent cobbles; 0 to 1 percent stones
Calcium carbonate equivalent: less than 5 percent
Reaction: neutral or slightly alkaline
Bt or Btk horizons
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 3 through 5 moist
Chroma: 3 or 4 dry or moist
Texture: sandy clay loam, loam, or clay loam
Rock fragments: 2 to 25 percent total range (mostly basalt with some sandstone)
2 to 20 percent gravel
0 to 5 percent cobbles
0 to 1 percent stones
Calcium carbonate equivalent: 5 to 35 percent
Reaction: slightly or moderately alkaline
Bk horizon (when present)
Hue: 7.5YR or 10YR
Chroma: 2 through 4 dry or moist
Rock fragments: 5 to 20 percent total range (mostly basalt with some sandstone)
5 to 20 percent gravel
0 to 1 percent cobbles
Calcium carbonate equivalent: 15 to 50 percent
2Bk horizons
Hue: 7.5YR or 10YR
Value: 5 through 8 dry, 3 through 8 moist
Chroma: 1 through 4 dry, 3 or 4 moist
Texture: sandy clay loam, coarse sandy loam, or loamy coarse sand
Rock fragments: 35 to 90 percent total range (mostly basalt with some sandstone)
35 to 70 percent gravel
10 to 30 percent cobbles
0 to 5 percent stones
Calcium carbonate equivalent: 5 to 55 percent
Reaction: moderately or strongly alkaline
C horizon (when present)
Hue: 7.5YR, 10YR, or 2.5YR
Chroma: 2 or 3 dry or moist
Texture: sand or coarse sand
Rock fragments: 5 to 70 percent total range mostly (basalt with some sandstone)
5 to 60 percent gravel
0 to 5 percent cobbles
0 to 1 percent stones
Calcium carbonate equivalent: less than 5 percent
COMPETING SERIES: These are the Naturita (CO) and Sheza (AZ) series. The Naturita soils have mean annual temperature of 45 degrees F. and colors as yellow as 2.5Y. The Sheza soils have colors redder than 7.5YR in the Bt horizon.
GEOGRAPHIC SETTING: The Eldado soils formed in eolian over alluvium and stream alluvium derived from basalt and sandstone and are on relict stream terraces on the footslopes of basalt capped mesas. Slopes are 1 to 5 percent. Elevations range from 6,300 to 7,300 feet. The mean annual temperature is 49 to 54 degrees F., and the mean annual precipitation is 10 to 13 inches. The frost free period is 120 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alesna soils on sides of mesas and volcanic cones; and the Azabache, Penistaja, and Tintero soils on fan terraces. The Alesna soils have greater than 35 percent clay in the particle size control section. The Azabache soils have natric horizons. The Penistaja and Tintero soils lack calcic horizons.
DRAINAGE AND PERMEABILITY: Well drained, low runoff, and moderate permeability.
USE AND VEGETATION: This series is used for rangeland and as a source of gravel. The present vegetation is cholla, fourwing saltbush, winterfat, blue grama, galleta, black grama, and sand dropseed.
DISTRIBUTION AND EXTENT: West central, New Mexico; MLRA 35, LRR-D. . This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES ESTABLISHED: McKinley County Area, New Mexico; McKinley County and Parts of Cibola and San Juan Counties, 2001.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: The zone from 0 to 2 inches. (A horizon)
Argillic horizon: The zone from 2 to 13 inches. (Btk1 and Btk2 horizons)
Calcic horizon: The zone from 9 to 25 inches. (Btk2 and Bk1 horizons)
Strongly contrasting particle-size feature: The zone from 25 to 72 inches. (2Bk2 and 2C horizons)
Classified according to Soil Taxonomy Second Edition, 1999.