LOCATION OWLSPRING NMEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Pachic Argiustolls
TYPICAL PEDON: Owlspring loam -- on a slightly concave toeslope sloping 6 percent to the south at 8,890 feet elevation -- rangeland. (Colors are for dry soil unless otherwise noted. When described, the soil was dry from 0 to 15 inches, and moist below 15 inches.)
A--0 to 5 inches; brown (7.5YR 4/2) loam, very dark brown (7.5YR 2.5/2) moist; common fine distinct dark yellowish brown (10YR 4/4) redox concentrations near root channels; weak thick platy structure parting to moderate fine granular; soft, very friable, slightly sticky and nonplastic; few fine and common very fine roots; few very fine irregularly shaped pores; 5 percent gravel; slightly acid (pH 6.2); abrupt smooth boundary. (2 to 7 inches thick)
Bt1--5 to 10 inches; dark reddish brown (5YR 3/2) loam, black (5YR 2.5/1) moist; common fine distinct brown (7.5YR 4/4) redox concentrations near root channels; strong coarse prismatic structure; slightly hard, friable, slightly sticky and slightly plastic; few medium, few fine, and common very fine roots; common very fine tubular pores; few thin clay films on faces of peds and lining pores; slightly acid (pH 6.4); clear wavy boundary. (5 to 17 inches thick)
Bt2--10 to 18 inches; very dark gray (5YR 3/1) loam, black (5YR 2.5/1) moist; strong medium prismatic structure parting to moderate medium subangular blocky; hard, friable, slightly sticky and slightly plastic; few fine and common very fine roots; few fine and many very fine tubular pores; common thin clay films on faces of peds and lining pores; slightly acid (pH 6.4); clear smooth boundary. (5 to 22 inches thick)
Bt3--18 to 25 inches; very dark gray (5YR 3/1) clay loam, black (5YR 2.5/1) moist; moderate fine prismatic structure parting to weak medium subangular blocky; hard, firm, moderately sticky and moderately plastic; few fine and few very fine roots; few fine and many very fine tubular pores; few moderately thick and common thin clay films on faces of peds and lining pores; neutral (pH 6.6); clear smooth boundary. (0 to 9 inches thick)
Btb--25 to 31 inches; dark reddish gray (5YR 4/2) sandy clay loam, dark reddish brown (5YR 3/2) moist; few fine prominent yellowish red (5YR 4/6) redox concentrations; weak fine prismatic structure parting to strong medium angular blocky; hard, firm, moderately sticky and moderately plastic; few fine and few very fine roots; few fine and common very fine tubular pores; many moderately thick clay films on faces of peds; neutral (pH 6.8); clear wavy boundary. (6 to 12 inches thick)
Btgb--31 to 43 inches; pinkish gray (7.5YR 6/2) sandy clay loam, brown (7.5YR 4/2) moist; common medium prominent yellowish red (5YR 4/6) redox concentrations; moderate medium prismatic structure parting to weak coarse subangular blocky; hard, firm, slightly sticky and slightly plastic; few very fine roots; few fine and common very fine tubular pores; one inch thick lens of charcoal at 32 inches; common moderately thick and few thin clay films on faces of peds; neutral (pH 6.8); gradual smooth boundary. (0 to 12 inches thick)
BCtb--43 to 66 inches; brown (7.5YR 5/4) fine sandy loam, brown (7.5YR 4/4) moist; common fine prominent strong brown (7.5YR 4/6) redox concentrations; weak coarse prismatic structure parting to moderate coarse subangular blocky; slightly hard, friable, slightly sticky and nonplastic; few very fine roots; few medium and fine and common very fine tubular pores; common thin clay films on faces of peds; 5 percent gravel; neutral (pH 6.8); abrupt wavy boundary. (6 to 23 inches thick)
C1--66 to 72 inches; pale brown (10YR 6/3) gravelly sandy loam, brown (10YR 4/3) moist; common fine prominent yellowish brown (10YR 5/8) redox concentrations; weak fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; few very fine roots; few very fine tubular pores; 25 percent gravel and 5 percent cobbles; neutral (pH 6.8); abrupt wavy boundary. (0 to 13 inches thick)
2C2--72 to 81 inches; light brownish gray (2.5Y 6/2) with strong brown (7.5YR 5/6) very fine sandy loam, dark grayish brown (2.5Y 4/2) with strong brown (7.5YR 4/6) moist; common medium prominent gray (10YR 5/1) redox deletions and common fine prominent yellowish red (5YR 4/6) redox concentrations; massive; soft, friable, slightly sticky and nonplastic; few very fine roots; few fine and common very fine tubular pores; 10 percent soft tuff gravel; neutral (pH 6.8); clear smooth boundary.
2Cr--81 inches; soft, basaltic tuff bedrock.
TYPE LOCATION: San Juan County, New Mexico; on the Navajo Indian Reservation about 9.5 miles west of Sheep Springs; 2,650 feet west and 1,150 feet north of the southeast corner of sec. 28, T.22N., R.19W; Latitude 36 degrees 6 minutes 27 seconds N and Longitude 108 degrees 52 minutes 18 seconds W.
RANGE IN CHARACTERISTICS:
Soil moisture - Typically, the soil moisture control section is moist in all parts from January to May and intermittently moist in some part from June to December. Typic ustic soil moisture regime.
Soil temperature - 42 to 44 degrees F.
Mean summer soil temperature - 59 to 62 degrees F.
Depth to seasonal high water table - 2.0 to 3.5 feet
Reaction - ranges from slightly acid in the surface to neutral in the subsoil and substratum
Silicate clay content, control section weighted average - 20 to 27 percent
Depth to base of Mollic epipedon and top of buried soil - 19 to 38 inches
Depth to top of Argillic horizon - 2 to 7 inches
Depth to redoximorphic features - 0 to 20 inches
Organic carbon content - 0.6 to 4.6 percent in Mollic epipedon
A horizon
Hue: 7.5YR, 10YR, N/
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 0 through 3, dry or moist
Rock fragments: 0 to 5 percent gravel
Redoximorphic features: none to common, fine, faint to distinct, brown, strong brown, or dark yellowish brown redox concentrations
Bt horizons
Hue: 5YR, 7.5YR, N/
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 0 through 2, dry or moist
Texture: loam, clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 5 percent gravel
Redoximorphic features: none to common, fine, faint to distinct, brown, strong brown, or dark yellowish brown redox concentrations, usually in upper horizons
Btb horizons
Hue: 5YR, 7.5YR
Value: 4 through 6 dry, 3 or 4 moist
Chroma: 2 through 4, dry or moist
Clay content: 20 to 35 percent
Rock fragments: 0 to 10 percent;
0 to 5 percent gravel,
0 to 5 percent cobbles
Redoximorphic features: few to common, fine to medium, distinct or prominent, brown, strong brown, or yellowish red redox concentrations; zones of strong gleying marked by matrix chromas of 1 or 2, are present in some pedons
BCtb horizon - Hue: 7.5YR, 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 through 4, dry or moist
Texture: fine sandy loam, sandy loam
Clay content: 16 to 20 percent
Rock fragments: 5 to 15 percent;
5 to 10 percent gravel,
0 to 5 percent cobbles
Redoximorphic features: few to common, fine to medium, distinct or prominent, yellowish brown, brown, or strong brown redox concentrations, and grayish brown redox depletions
C1 horizon
Hue: 7.5YR, 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: gravelly sandy loam, gravelly fine sandy loam
Clay content: 8 to 18 percent
Rock fragments: 15 to 35 percent;
10 to 25 percent gravel,
0 to 10 percent cobbles
Redoximorphic features: few to common, fine to medium, distinct or prominent, yellowish brown, brown, or strong brown redox concentrations
2C2 horizon
Hue: 10YR, 2.5Y
Value: 5 or 6 dry
Chroma: 2 through 6, dry or moist
Texture: very fine sandy loam, fine sandy loam
Clay content: 8 to 18 percent
Redoximorphic features: common, fine to medium, prominent, brownish yellow, or yellowish red redox concentrations, and grayish brown or gray redox depletions
Other features: 10 to 30 percent soft tuff fragments
COMPETING SERIES: These are the Bigpaw (AZ) and Jekley (NM) series. Bigpaw soils are well drained and do not have redoximorphic features within 40 inches. Jekley soils are deep to bedrock.
GEOGRAPHIC SETTING: Owlspring soils are on toeslopes of calderas and mesas. They formed in alluvium and residuum derived from Tertiary basalt and basaltic tuff. Slopes range from 1 to 10 percent. Elevation ranges from 8,500 to 9,000 feet. The mean annual precipitation is 20 to 22 inches with more than 50 percent falling as snow from winter storms. The mean annual temperature is 40 to 42 degrees F. The average frost-free period is 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sonsela, Todacheene, Viewpoint, and Washpass soils. Sonsela soils are loamy-skeletal, lack mollic epipedons, and occur on south-facing backslopes. Todacheene soils are fine-loamy, well drained, and occur on adjacent footslopes. Viewpoint soils are loamy, shallow to basalt, and occur on adjacent shoulders and knolls. Washpass soils are coarse-loamy, have thin mollic epipedons, and occur on north-facing slopes in a cryic soil temperature regime.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; medium runoff; moderately slow permeability. These soils have frequent, very brief periods of flooding between April and September. This flooding is in response to snowmelt in spring and heavy rainfall in summer following prolonged, high-intensity convective thunderstorms.
USE AND VEGETATION: Owlspring soils are used for livestock grazing. Present vegetation is Kentucky bluegrass, redtop, slender wheatgrass, needleleaf sedge, Baltic rush, western yarrow, common dandelion, and Rocky Mountain iris.
DISTRIBUTION AND EXTENT: Owlspring soils are of small extent on the Defiance Uplift-Chuska Mountains portion of the Colorado Plateau province in northwest New Mexico and northeast Arizona. MLRA 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Shiprock Area, Parts of San Juan County, New Mexico and Apache County, Arizona; 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 31 inches (A, Bt1, Bt2, Bt3 and 2Btb horizons)
Pachic subgroup - The presence of a mollic epipedon that is greater than 16 inches thick
Argillic horizon - The zone from 5 to 25 inches (Bt1, Bt2, and Bt3 horizons)
Buried soil - The presence of a buried paleosol at 25 to 66 inches (Btb, Btgb, and BCtb horizons)
Aquic conditions - Saturation, reduction, and redoximorphic features present between 20 and 81 inches (Btb, Btgb, BCtb, C1, and 2C2 horizons)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.
ADDITIONAL DATA: Organic carbon values were determined for three horizons from the type location by Inter-Mountain Laboratories, Inc. The particle-size control section of the typifying pedon at the type location, was wet sieved to determine percent of size fraction larger than very fine sand (less than 0.1 mm). The weighted average of the control section was 4 percent coarser than very fine sand.
Updated and revised for the correlation of Ft. Defiance Area AZ715 2/08 DWD