LOCATION ANTONCHICO NMEstablished Series
TAXONOMIC CLASS: Fine-loamy over fragmental, micaceous, mesic Calcidic Argiustolls
TYPICAL PEDON: Antonchico gravelly sandy loam--on a beveled summit of a hill sloping 4 percent to the southwest at 7,315 feet elevation-pinyon-juniper forestland. (Colors are for dry soil unless otherwise noted. When described, the soil was moist from 3 to 20 inches and otherwise dry throughout.)
A--0 to 2 inches; dark grayish brown (10YR 4/2) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak thick platy structure parting to moderate coarse granular; soft, very friable, slightly sticky and slightly plastic; few fine and common very fine roots; few very fine irregularly shaped pores; 20 percent gravel and 5 percent cobbles; neutral (pH 6.8); abrupt smooth boundary. (2 or 3 inches thick)
Bt1--2 to 7 inches; brown (7.5YR 4/2) gravelly sandy clay loam, dark brown (7.5YR 3/2) moist; moderate fine subangular blocky structure; slightly hard, firm, moderately sticky and slightly plastic; common fine and common very fine roots; few fine and few very fine tubular pores; few distinct and common faint clay films on faces of peds and lining pores; 15 percent gravel; neutral (pH 6.8); clear smooth boundary. (3 to 8 inches thick)
Bt2--7 to 14 inches; brown (7.5YR 4/3) gravelly sandy clay loam, dark brown (7.5YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, firm, moderately sticky and slightly plastic; few medium, common fine, and few very fine roots; few medium and few fine tubular pores; common distinct and common faint clay films on faces of peds and lining pores; 25 percent gravel; 2 percent paragravel and 2 percent paragravel; neutral (pH 6.8); gradual wavy boundary. (5 to 11 inches thick)
Bt3--14 to 20 inches; brown (10YR 5/3) gravelly sandy clay loam, brown (10YR 4/3) moist; moderate medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium, few fine and few very fine roots; few fine tubular pores; common faint clay films on faces of peds and lining pores; 25 percent gravel; 5 percent paragravel and 5 percent paragravel; neutral (pH 6.8); abrupt wavy boundary. (0 to 10 inches thick)
2BCk--20 to 42 inches; cobbles; fine earth is very pale brown (10YR 8/2) loamy coarse sand, light gray (10YR 7/2) moist; massive; loose, nonsticky and nonplastic; few medium, few fine, and few very fine roots; 60 percent gravel and 35 percent cobbles; rock fragments are angular and separated by fractures devoid of fine earth in some part; violently effervescent, secondary calcium carbonate segregated as many medium irregularly shaped coats on rock fragments and as soft masses (26 percent calcium carbonate equivalent); moderately alkaline (pH 8.2); clear wavy boundary. (16 to 28 inches thick).
2R--42 inches; indurated schist bedrock
TYPE LOCATION: Santa Fe County, New Mexico; about 2 1/4 miles southeast of Seton Village within the nonsectionized Sebastian de Vargas Grant, projected location is 1,300 feet west and 800 feet north of the southeast corner of Sec. 29, T16N, R10E; USGS Seton Village 7.5 minute topographic quadrangle; Latitude 35 degrees 34 minutes 57 seconds North and Longitude 105 degrees 53 minutes 52 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.
Thickness of mollic epipedon - 10 to 18 inches
Depth to base of argillic horizon - 10 to 20 inches
Mica content - 25 to 40 percent in coarse silt to fine sand fractions
Depth to calcareous material (as visible secondary calcium carbonate) - 16 to 20 inches
Depth to calcic horizon - 16 to 20 inches
Depth to lithic contact - 40 to 60 inches
Rock fragment lithology: granite, gneiss, and schist
Particle-size control section (weighted averages)
Upper part
Silicate clay content: 20 to 35 percent
Sand content: 40 to 60 percent
Fine sand or coarser content: 30 to 45 percent
Rock fragment content: total range is 15 to 30 percent with 15 to 25 percent gravel and 0 to 5 percent cobbles
Mica content: 45 to 55 percent (by grain count)
Lower part
Silicate clay content: 10 to 18 percent
Sand content: 55 to 70 percent
Fine sand or coarser content: 45 to 65 percent
Rock fragment content: total range is 90 to 95 percent with 55 to 65 percent gravel and 30 to 35 percent cobbles
Mica content: 45 to 55 percent (by grain count)
A horizon
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Upper Bt horizons
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 4, dry or moist
Texture: gravelly sandy clay loam or gravelly clay loam
Rock fragment content: total range is 15 to 30 percent
15 to 25 percent gravel
0 to 5 percent cobbles
Paragravel and paracobble content: 0 to 5 percent
Lower Bt horizon
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: gravelly sandy clay loam or gravelly clay loam
Rock fragment content: total range is 15 to 30 percent
15 to 25 percent gravel
0 to 5 percent cobbles
Paragravel content: 0 to 5 percent
2BCk horizon
Hue: 7.5YR or 10YR
Value: 7 or 8 dry, 5 to 7 moist
Chroma: 2 or 3, dry or moist
Texture: cobbles or gravel
Clay content of fine earth: 10 to 18 percent
Rock fragment content: total range is 90 to 95 percent
55 to 65 percent gravel
30 to 35 percent cobbles
Calcium carbonate equivalent: 20 to 40 percent
Paragravel content: 0 to 10 percent
COMPETING SERIES: There are no competing series in this family. The Setonville series in a closely related family does not have a mollic epipedon and has mixed mineralogy.
GEOGRAPHIC SETTING: Antonchico soils are on beveled summits of hills and knolls. They formed in alluvium derived locally from Precambrian granite, gneiss, and schist over residuum of Precambrian schist bedrock. Slopes are 3 to 5 percent. Elevation ranges from 6,300 to 8,200 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, Atalaya, Enmedio and Setonville soils. Arnor soils are fine-loamy, do not have calcic horizons and fragmental materials, and occur on toeslopes of hills. Atalaya soils are coarse-loamy over fragmental, do not have calcic horizons, and occur on beveled summits. Enmedio soils are loamy-skeletal over fragmental, do not have mollic epipedons or calcic horizons, and occur on backslopes of hills. Setonville soils are loamy-skeletal over fragmental, do not have mollic epipedons, and occur on adjacent footslopes of hill and knolls.
DRAINAGE AND PERMEABILITY: Well drained; medium surface runoff; permeability is moderate.
USE AND VEGETATION: Antonchico soils are used for urban development, cord wood products, livestock grazing, and recreation. The historic climax vegetation is ponderosa pine, Gambel's oak, mountain muhly, and muttongrass. The ecological site is Pinus ponderosa/Quercus gambleii (F048AY010NM).
DISTRIBUTION AND EXTENT: Antonchico 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. Antonchico is a street name in Santa Fe.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to a depth of about 14 inches. (A, Bt1, and Bt2 horizons)
Argillic horizon - The zone from 2 to about 20 inches. (Bt1, Bt2, and Bt3 horizons)
Calcic horizon - The zone from 20 to about 42 inches. (2BCk horizon)
Fragmental feature -from 20 to about 42 inches. (2BCk horizon)
Lithic contact - The presence of indurated schist bedrock at 42 inches. (2R layer)
Particle-size control section - The zone from 2 to 40 inches. (Bt1, Bt2, Bt3, and 2BCk horizons
Taxonomic version: Classified according to Keys to Soil Taxonomy, Tenth Edition, 2006.
ADDITIONAL DATA: Calcium carbonate equivalence was determined using a calcimeter.
The mineralogy class was changed from paramicaceous to micaceous in 07/2010 by the National Soil Survey Center on request of the responsible MLRA regional office. The change was necessary based on the eleventh edition of the Keys to Soil Taxonomy, 2010.