LOCATION XENMACK NMEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ustic Haplocalcids
TYPICAL PEDON: Xenmack extremely gravelly sandy loam--on a riser of a strath terrace remnant sloping 47 percent to the southwest at 5,880 feet elevation--rangeland. (Colors are for dry soil unless otherwise noted. When described, the soil was slightly moist from 2 to 10 inches and otherwise dry throughout.)
ABk--0 to 2 inches; brown (7.5YR 5/3) extremely gravelly sandy loam, brown (7.5YR 4/3) moist; weak thick platy structure parting to moderate fine granular; soft, very friable, slightly sticky and nonplastic; few fine and common very fine roots; few fine and few very fine irregularly shaped pores; 50 percent gravel and 15 percent cobbles; strongly effervescent, secondary calcium carbonate segregated as common fine irregularly shaped coats on rock fragments and coarse sand grains; moderately alkaline (pH 8.0); clear smooth boundary. (2 or 3 inches thick)
Bk1--2 to 7 inches; brown (7.5YR 5/3) very gravelly sandy loam, brown (7.5YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium, common fine, and common very fine roots; few fine and common very fine tubular pores; 35 percent gravel and 5 percent cobbles; strongly effervescent, secondary calcium carbonate segregated as common fine irregularly shaped coats on faces of peds and on rock fragments; moderately alkaline (pH 8.2); clear wavy boundary. (3 to 5 inches thick)
Bk2--7 to 16 inches; light brown (7.5YR 6/3) with pink (7.5YR 7/3) gravelly loam, brown (7.5YR 5/4) with light brown (7.5YR 6/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few coarse, few medium, common fine, and common very fine roots; few fine and common very fine tubular pores; 25 percent gravel and 5 percent cobbles; violently effervescent, secondary calcium carbonate segregated as common medium irregularly shaped coats on faces of peds and on rock fragments; moderately alkaline (pH 8.4); clear wavy boundary. (4 to 9 inches thick)
Bk3--16 to 24 inches; light brown (7.5YR 6/3) gravelly loam, brown (7.5YR 5/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few coarse, few medium, common fine, and common very fine roots; few fine and common very fine tubular pores; 25 percent gravel and 5 percent cobbles; violently effervescent, secondary calcium carbonate segregated as common fine and medium irregularly shaped coats on faces of peds and on rock fragments; moderately alkaline (pH 8.2); clear irregular boundary. (0 to 13 inches thick)
2BCk1--24 to 29 inches; light brown (7.5YR 6/4) paragravelly clay loam, brown (7.5YR 5/4) moist; weak coarse subangular blocky structure; hard, friable, moderately sticky and slightly plastic; few coarse, few medium, few fine, and few very fine roots; few fine and common very fine tubular pores; 20 percent siltstone paragravel; strongly effervescent, secondary calcium carbonate segregated as many fine irregularly shaped coats on faces of peds and on pararock fragments; moderately alkaline (pH 8.2); clear smooth boundary. (4 to 9 inches thick)
2BCk2--29 to 37 inches; light brown (7.5YR 6/3) very paragravelly loam, brown (7.5YR 5/4) moist; massive, platy rock structure; slightly hard, friable, slightly sticky and slightly plastic; few coarse, few medium, few fine, and few very fine roots; few very fine irregularly shaped pores; 45 percent siltstone paragravel; strongly effervescent, secondary calcium carbonate segregated as common fine and medium irregularly shaped coats on pararock fragments; moderately alkaline (pH 8.4); clear wavy boundary. (4 to 10 inches thick)
2Cr--37 to 47 inches; interbedded moderately cemented micaceous sandstone and siltstone bedrock.
TYPE LOCATION: Santa Fe County, New Mexico; on the Pojoaque Indian Reservation about 1 mile southwest of Pojoaque; 100 feet east and 1,000 feet south of the northwest corner of section 18, T.19N., R.9E.; USGS Espanola 7.5 minute topographic quadrangle; Latitude 35 degrees 52 minutes 55 seconds North and Longitude 106 degrees 2 minutes 8.5 seconds West, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - The soil moisture control section is intermittently moist in some part from July to October and December to March. The soils are driest in May and June. The soil moisture regime is aridic bordering on ustic.
Mean annual soil temperature - 52 to 54 degrees F.
Depth to paralithic contact - 20 to 40 inches to moderately cemented bedrock
Depth to calcic horizon - 2 to 3 inches
Volcanic glass content: 5 to 10 percent in the coarse silt plus sand fraction
Lithology of rock fragments: granite, gneiss, and schist
Particle-size control section (weighted averages)
Silicate clay content: 18 to 27 percent
Fine sand or coarser content: 15 to 45 percent
Rock fragment content: 15 to 35 percent, mostly gravel
Mica content: 1 to 3 percent (by grain count)
Reaction - moderately alkaline
Salinity, mmhos/cm - 0 to 2
Sodicity, SAR - 0 to 4
ABk horizon
Chroma: 3 or 4, dry or moist
Rock fragments: total range is 60 to 70 percent; 45 to 50 percent gravel, 15 to 20 percent cobbles
Calcium carbonate equivalent: 1 to 3 percent
Bk1 horizon
Value: 5 or 6 dry
Chroma: 3 or 4, dry or moist
Texture: very gravelly sandy loam or very gravelly fine sandy loam
Clay content: 14 to 18 percent
Rock fragments: total range is 35 to 50 percent; 30 to 40 percent gravel, 5 to 10 percent cobbles
Calcium carbonate equivalent: 5 to 10 percent
Bk2 horizon
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: gravelly loam or gravelly fine sandy loam; some pedons have textures of gravelly sandy loam or gravelly very fine sandy loam
Clay content: 14 to 18 percent
Rock fragments: total range is 15 to 35 percent; 15 to 30 percent gravel, 0 to 5 percent cobbles
Calcium carbonate equivalent: 5 to 10 percent
Bk3 horizon
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: gravelly loam or gravelly sandy clay loam
Clay content: 20 to 27 percent
Rock fragments: total range is 15 to 35 percent; 15 to 30 percent gravel, 0 to 5 percent cobbles
Calcium carbonate equivalent: 5 to 10 percent
Upper 2BCk horizon
Hue: 5YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: paragravelly loam or paragravelly clay loam; some pedons have textures of paragravelly sandy loam or very paragravelly very fine sandy loam
Clay content: 20 to 35 percent
Pararock fragments: 15 to 25 percent paragravel
Calcium carbonate equivalent: 5 to 10 percent
Lower 2BCk horizon
Hue: 5YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: very paragravelly loam or very paragravelly very fine sandy loam; Fine sand or coarser content decreases with depth to the paralithic contact; some pedons have textures of very paragravelly sandy loam or paragravelly very fine sandy loam
Clay content: 18 to 27 percent
Pararock fragments: 35 to 45 percent paragravel
Calcium carbonate equivalent: 5 to 10 percent
COMPETING SERIES: These are the Abra, Bighams, Bowdish, Copeman, Creel, Darvey, Hernandez, Honlu, Kimera, Numa, and Peachsprings series. Abra, Copeman, Darvey, Hernandez, Honlu, Kimera, Numa, and Peachsprings soils are deep or very deep to bedrock. Bighams soils contain 15 to 40 percent calcium carbonate equivalent in the calcic horizon and have Bw horizons. Bowdish soils have rock fragments of sandstone and limestone. Creel soils have annual soil temperature greater than 54 degrees. In addition, Creel, Darvey, Kimera and Numa soils are in the Western Great Plains (LRR-G MLRAs 70 and 69) and are more moist in May and June.
GEOGRAPHIC SETTING: Xenmack soils are on risers of strath terrace remnants. They formed in colluvium derived from Precambrian granite, gneiss, and schist over residuum derived from Tertiary micaceous sandstone and siltstone. Slopes are 25 to 60 percent. Elevation ranges from 5,400 to 6,600 feet. The mean annual precipitation is 9 to 12 inches with about 45 percent falling as rain from high-intensity convective thunderstorms between July and September. The mean annual air temperature is 50 to 52 degrees F. The frost-free period is 150 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Depolvo, Jaconita, Koshare, and Sueleros soils. Depolvo soils are fine-silty, have argillic horizons, and occur on treads of strath terrace remnants. Jaconita soils are sandy-skeletal, very deep to bedrock, and occur on adjacent risers. Koshare soils are very deep, have cambic horizons, and occur on toeslopes of ridges and hills. Sueleros soils are very deep, have natric horizons, and occur on treads of strath terrace remnants.
DRAINAGE AND PERMEABILITY: Well drained; medium surface runoff; permeability is moderately slow.
USE AND VEGETATION: Xenmack soils are used for urban development, livestock grazing, and recreation. The historic climax vegetation is blue grama, sideoats grama, black grama, galleta, New Mexico feathergrass, twoneedle pinyon, and oneseed juniper. The ecological site is Gravelly(R036XB114NM).
DISTRIBUTION AND EXTENT: Xenmack soils are of small extent on the southeastern Espanola Basin part of the Basin and Range province in northcentral New Mexico. The MLRA is 36.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Santa Fe County, New Mexico; Santa Fe Area Soil Survey Update; 2008. The name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to a depth of about 2 inches. (ABk horizon)
Calcic horizon - The zone from 2 to about 16 inches. (Bk1 and Bk2 horizons)
Paralithic contact - The boundary at about 37 inches to underlying moderately cemented bedrock. (2Cr layer)
Particle-size control section - The zone from 10 to 40 inches (part of Bk2, Bk3, 2BCk1, 2BCk2 horizons)
Series control section - The zone from 0 to 47 inches (all horizons and upper 10 inches of paralithic material).
Taxonomic version: Classified according to Keys to Soil Taxonomy, Tenth Edition, 2006.