LOCATION DELTAJO NMEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Haplocalcids
TYPICAL PEDON: Deltajo very channery loam-on a west facing cuesta, dipslope of 24 percent at 5,540 feet elevation--rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; reddish brown (5YR 4/4) very channery loam, dark reddish brown (5YR 3/4) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; few fine and very fine roots; few very fine vesicular pores; 40 percent channers and 5 percent flagstones; strongly effervescent; moderately alkaline; clear smooth boundary. (2 to 4 inches thick)
Bk1--2 to 6 inches; reddish brown (5YR 5/4) channery loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few fine and many very fine roots; few very fine vesicular pores; 25 percent channers; violently effervescent; secondary carbonates segregated in few fine filaments lining soil pores; moderately alkaline; clear smooth boundary. (4 to 11 inches thick)
Bk2--6 to 13 inches; light reddish brown (5YR 6/4) channery loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few fine and common very fine roots; few very fine discontinuous irregularly shaped pores; 20 percent channers; violently effervescent; secondary carbonates segregated as coatings on the undersides of rock fragments and also in few fine irregularly shaped soft masses; moderately alkaline; clear wavy boundary. (6 to 9 inches thick)
C--13 to 22 inches; reddish brown (2.5YR 5/4) channery silt loam, reddish brown (2.5YR 4/4) moist; massive; platy rock structure inherited from underlying parent material; slightly hard, friable, sticky and plastic; few fine and very fine roots; 20 percent channers; slightly effervescent; moderately alkaline; clear wavy boundary. (8 to 16 inches thick)
2Cr--22 to 33 inches; reddish brown (5YR 4/3) soft siltstone bedrock, dark reddish brown (5YR 3/3) moist; strata are approximately 0.5 inch thick and contain no plant roots; clear irregular boundary. (10 to 20 inches thick)
2R--33 inches; fine grained calcareous sandstone bedrock; with depth this stratum grades into, and is interbedded with, softer siltstone strata.
TYPE LOCATION: Socorro County, New Mexico; 12 miles northeast of Socorro and about 1 mile north of Canoncito de la Uva; 250 feet north and 150 feet east of the very center of section 3, T. 2 S., R. 2 E.
RANGE IN CHARACTERISTICS:
Depth to soft siltstone bedrock: 20 to 40 inches.
Thin strata of hard sandstone are usually present below the paralithic siltstone contact, but with depth these hard beds grade into, and are interbedded with, softer siltstone strata.
Secondary calcium carbonate in the calcic horizon ranges from 15 to 35 percent calcium carbonate equivalence.
Percent clay in the control section ranges from 18 to 27 percent.
Rock fragments are sandstone and hard siltstone.
Soil moisture: Typically the control section is intermittently moist from July to September following convective storms. Typic aridic moisture regime.
A horizon
Hue: 5YR dry
Value: 4 or 5 dry
Chroma: 4 dry
Percent rock fragments: 30 to 40 channers, 5 to 10 flagstones and cobbles
Bk horizon
Hue: 2.5YR or 5YR
Value: 4 through 7 dry, 3 through 5 moist
Chroma: 4 through 6
Percent rock fragments: 10 to 25 channers, 5 to 10 pebbles
C horizon
Hue: 2.5YR or 5YR
Value: 4 to 5 dry, 3 or 4 moist
Chroma: 4 through 6
Texture: channery loam or channery silt loam
Percent rock fragments: 15 to 25 channers, 0 to 5 flagstones
COMPETING SERIES: These are the Bridge (AZ), Chutum (AZ), Laverkin (UT), Sotim (NM), Turney (NM) and Weedpatch (CA) series. Bridge soils are moderately deep to volcanic ash or tuff and have hues yellower than 5YR. Chutum, Laverkin, Sotim, and Turney soils are all deeper than 40 inches. Weedpatch soils have hue commonly yellower than 10YR. In addition, Weedpatch soils are in the San Joaquin Valley (MLRA 17) and receive mostly winter precipitation and are usually dry from April through November.
GEOGRAPHIC SETTING: Deltajo soils are on cuestas that are underlain by calcareous siltstone and sandstone. Deltajo soils formed in alluvium derived from siltstone and fine-grained sandstone. Slopes range from 5 to 45 percent. Elevation ranges from 5,000 to 5,700 feet. The average annual precipitation is 8 to 10 inches and the average annual temperature is 59 to 64 degrees F. The average frost-free period is 180 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Berino, Dona Ana, Lozier, Mimbres, Wink and the competing Turney soils. Berino, Dona Ana, Mimbres and Wink soils are more than 40 inches deep. Lozier soils are loamy-skeletal and less than 20 inches deep to limestone bedrock.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff, moderate permeability.
USE AND VEGETATION: Deltajo soils are used for livestock grazing. Present vegetation is black grama, creosotebush, Tridens spp., mariola, blue grama, cacti and ocotillo.
DISTRIBUTION AND EXTENT: Deltajo soils are moderately extensive in south central New Mexico. MLRA 42.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Socorro County, New Mexico, 1984.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: the zone from 0 to 2 inches. (A horizon)
Calcic horizon: the zone from 2 to 13 inches. (Bk horizon)
Paralithic contact: soft siltstone at 22 inches. (2Cr horizon)
Classified according to Soil Taxonomy Second Edition, 1999
ADDITIONAL DATA: Calcium carbonate equivalence determined with use of field volume calcimeter.