LOCATION ATALAYA NMEstablished Series
TAXONOMIC CLASS: Coarse-loamy over fragmental, mixed, superactive, mesic Aridic Haplustalfs
TYPICAL PEDON: Atalaya very gravelly sandy loam, stony--on a beveled summit of a hill sloping 10 percent to the southeast at 7,375 feet elevation, pinyon-juniper forestland. (Colors are for dry soil unless otherwise noted. When described, the soil was dry throughout.)
A--0 to 1 inch; brown (7.5YR 4/3) very gravelly sandy loam, dark brown (7.5YR 3/3) moist; weak coarse platy structure parting to moderate medium granular; soft, very friable, slightly sticky and nonplastic; few fine and common very fine roots; few fine and few very fine irregularly shaped pores; 45 percent gravel, 10 percent cobbles, and 1 percent stones; neutral (pH 6.8); abrupt smooth boundary. (1 to 3 inches thick)
Bt1--1 to 4 inches; reddish brown (5YR 4/4) gravelly coarse sandy loam, dark reddish brown (5YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common medium, few fine, and common very fine roots; few very fine tubular pores; common faint clay films on faces of peds; 20 percent gravel and 5 percent cobbles; 30 percent paragravel; neutral (pH 6.8); clear wavy boundary. (3 to 6 inches thick)
Bt2--4 to 7 inches; yellowish red (5YR 5/6) gravelly coarse sandy loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium, few fine, and few very fine roots; few very fine tubular pores; common faint clay films on faces of peds and few faint clay films on rock fragments; 25 percent gravel and 5 percent cobbles; 35 percent paragravel; neutral (pH 7.0); clear irregular boundary. (3 to 6 inches thick)
Bt3--7 to 12 inches; reddish brown (5YR 5/4) gravelly coarse sandy loam, reddish brown (5YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common medium, few fine, and few very fine roots; few very fine tubular pores; few faint clay films on faces of peds and common faint clay films on rock fragments; 25 percent gravel and 5 percent cobbles; 25 percent paragravel and 5 percent paracobbles; neutral (pH 7.0); gradual wavy boundary. (4 to 9 inches thick)
BC1--12 to 24 inches; grayish brown (10YR 5/2) with yellowish brown (10YR 5/6) gravelly coarse sandy loam, dark grayish brown (10YR 4/2) with dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; few coarse, few medium, few fine, and few very fine roots; few very fine tubular pores; clay commonly forming in situ on rock fragments; 15 percent gravel and 5 percent cobbles; 50 percent paragravel and 10 percent paracobbles; neutral (pH 6.8); clear wavy boundary. (10 to 16 inches thick)
BC2--24 to 35 inches; grayish brown (10YR 5/2) with yellowish brown (10YR 5/4) cobbly coarse sandy loam, dark grayish brown (10YR 4/2) with dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; few medium and few very fine roots; clay forming in situ on some rock fragments; 10 percent gravel and 10 percent cobbles; 50 percent paragravel and 10 percent paracobbles; neutral (pH 6.8); clear wavy boundary. (9 to 15 inches thick)
2CBk--35 to 50 inches; gravel; fine earth is yellowish brown (10YR 5/4) coarse sand, dark yellowish brown (10YR 4/4) moist; massive; loose, nonsticky and nonplastic; few coarse, few medium, and few fine roots; 70 percent gravel and 25 percent cobbles; rock fragments are angular and separated by fractures devoid of fine earth in some part; strongly to violently effervescent, secondary calcium carbonate segregated as many medium irregularly shaped coats on rock fragments (3 percent calcium carbonate equivalent); moderately alkaline (pH 8.4); clear wavy boundary. (6 to 18 inches thick)
2R--50 inches; hard gneiss bedrock
TYPE LOCATION: Santa Fe County, New Mexico; about 2 miles southeast of Seton Village within the nonsectionized Sebastian de Vargas Grant, projected location is 1,350 feet east and 2,000 feet south of the northwest corner of section 32, T.16N., R.10E.; USGS Seton Village 7.5 minute topographic quadrangle; Latitude 35 degrees 34 minutes 30 seconds North and Longitude 105 degrees 54 minutes 23 seconds West, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - The soil moisture control section is moist in all parts during the 60 days following the winter solstice. It is moist in some part less than 40 percent and moist in all parts less than 25 percent of the time when the soil temperature at 20 inches is above 41 degrees F. The soils are driest in May and June. The soil moisture regime is ustic bordering on aridic.
Mean annual soil temperature - 48 to 50 degrees F.
Depth to base of argillic horizon - 10 to 17 inches
Depth to calcareous material (as visible secondary calcium carbonate) - 31 to 40 inches
Depth to lithic contact - 40 to 60 inches
Lithology of rock fragments: granite, gneiss, or schist
Particle-size control section (weighted averages)
Silicate clay content: 10 to 18 percent
Sand content: 35 to 55 percent
Fine sand or coarser content: 25 to 40 percent
Rock fragment content: total range is 20 to 35 percent
15 to 25 percent gravel
5 to 10 percent cobbles
Mica content: 25 to 45 percent (by grain count)
A horizon
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Rock fragment content: total range is 35 to 60 percent
30 to 50 percent gravel
5 to 10 percent cobbles
0 to 1 percent stones
Bt horizons
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 4 or 6, dry or moist
Texture: gravelly coarse sandy loam or gravelly sandy loam
Clay content: 10 to 18 percent
Rock fragment content: total range is 20 to 35 percent
15 to 25 percent gravel
5 to 10 percent cobbles
Paragravel content: 25 to 45 percent
Paracobble content: 0 to 10 percent
BC1 horizon
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 to 6, dry or moist
Texture: gravelly coarse sandy loam or gravelly sandy loam
Clay content: 8 to 12 percent
Rock fragment content: total range is 20 to 35 percent
15 to 25 percent gravel
5 to 10 percent cobbles
Paragravel content: 45 to 55 percent
Paracobble content: 5 to 15 percent
BC2 horizon
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 to 4, dry or moist
Texture: cobbly coarse sandy loam or cobbly sandy loam
Clay content: 6 to 10 percent
Rock fragment content: total range is 20 to 35 percent
10 to 20 percent gravel
10 to 15 percent cobbles
Paragravel content: 50 to 60 percent
Paracobble content: 10 to 25 percent
2CBk horizon
Hue: 10YR or 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Clay content: 0 to 4percent
Calcium carbonate equivalent: 1 to 5 percent
Rock fragment content: total range is 90 to 95 percent
20 to 75 percent gravel
20 to 70 percent cobbles
COMPETING SERIES: There are no competing series in this family. The Antonchico series in a closely related family has a mollic epipedon.
GEOGRAPHIC SETTING: Atalaya soils are on beveled summits and shoulders of hills. They formed in alluvium and slope alluvium derived locally from Precambrian granite, gneiss, and schist over residuum of Precambrian granite or gneiss bedrock. Slopes are 5 to 15 percent. Elevation ranges from 6,400 to 8,500 feet. The mean annual precipitation is 14 to 16 inches with about 45 percent falling as rain from high-intensity convective thunderstorms between July and September. The mean annual air temperature is 47 to 49 degrees F. The frost-free period is 130 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arnor, Enmedio, and Setonville soils. Arnor soils are fine-loamy, do not have fragmental materials, and occur on toeslopes of hills. Enmedio soils are loamy skeletal over fragmental, have mollic epipedons, and occur on backslopes of hills. Setonville soils are loamy-skeletal over fragmental, have calcic horizons, and occur on footslopes of hills and knolls.
DRAINAGE AND PERMEABILITY: Well drained; medium surface runoff; permeability is moderately rapid in the surface and subsoil and very rapid in the lower substratum.
USE AND VEGETATION: Atalaya soils are used for urban development, cord wood products, livestock grazing, and recreation. The historic climax vegetation is blue grama, Gamble's oak, twoneedle pinyon, and oneseed juniper. The ecological site is Pinus edulis-Juniperus monosperma/Quercus gambeli/Bouteloua gracilis(F036XB134NM).
DISTRIBUTION AND EXTENT: Atalaya soils are of small extent on the southwestern Sangre de Cristo part of the Southern Rocky Mountains province in northcentral New Mexico. The MLRA is 48A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Santa Fe County, New Mexico; Santa Fe Area Soil Survey Update; 2008. Atalaya is a name of a mountain east of Santa Fe.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to a depth of about 1 inch. (A horizon)
Argillic horizon - The zone from 1 to about 12 inches. (Bt1, Bt2, and Bt3 horizons)
Fragmental feature - from 35 to about 50 inches. (2CBk horizon)
Lithic contact - hard gneiss bedrock at 50 inches. (2R layer)
Particle-size control section - The zone from 1 to 12 inches. (Bt1, Bt2, and Bt3 horizons)
Taxonomic version: Classified according to Keys to Soil Taxonomy, Tenth Edition, 2006.
ADDITIONAL DATA: Calcium carbonate equivalence was determined using a calcimeter. EC was determined with an instant EC salinity kit.