LOCATION ABARCA WYTentative Series
TAXONOMIC CLASS: Loamy-skeletal over sandy or sandy-skeletal, mixed, superactive, frigid Torriorthentic Haplustolls
TYPICAL PEDON: Abarca gravelly clay loam - grassland (Colors are for dry soil unless otherwise noted.)
A1--0 to 4 inches; grayish brown (10YR 5/2) gravelly clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, slightly plastic, slightly sticky; 20 percent gravel; calcareous; moderately alkaline, pH 8.0 (cresol red); clear smooth boundary. (2 to 8 inches thick).
A2--4 to 9 inches; brown (10YR 5/3) gravelly clay loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure that parts to coarse granular; slightly hard, very friable, slightly plastic, slightly sticky; 25 percent gravel; calcareous; moderately alkaline, pH 8.0 (cresol red); gradual wavy boundary. (0 to 13 inches thick).
Bk--9 to 30 inches; brown (10YR 5/3) very gravelly clay loam, brown (10YR 4/3) moist; massive; slightly hard, very friable, slightly plastic, slightly sticky; 45 percent gravel; visible secondary carbonate occurring as concretions and in thin seams and streaks; calcareous; moderately alkaline, pH 8.0 (cresol red); gradual wavy boundary. (10 to 33 inches thick).
2CBk--30 to 60 inches; very gravelly sand. Gravel fragments are lime coated in the upper part with the amount of lime decreasing with depth.
TYPE LOCATION: Uinta County, Wyoming. Approximately 800 feet south and 500 feet west of the N1/4 corner of Sec. 29, T15N, R120W.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is affected by peak periods of precipitation that occur in the spring and early summer. Ustic moisture regime bordering on aridic.
Mean annual soil temperature: about 43 degrees F
Mean summer soil temperature: about 60 degrees F
Depth to secondary calcium carbonate: 7 to 40 inches
Depth to lithologic discontinuity: 20 to 40 inches
Thickness of the mollic epipedon: 7 to 15 inches
Particle-size control section (weighted average):
Clay content: 18 to 35 percent in the upper part and less than 10 percent in the lower part
Sand content: 20 to 50 percent in the upper part and greater than 80 percent in the lower part
Rock fragments: 35 to 85 percent gravel and cobble
A horizon:
Hue: 7.5YR to 5Y?
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 to 3 dry or moist
Calcium carbonate equivalent: 2 to 14 percent
ESP: 0 to 15 percent
Reaction: slightly to strongly alkaline
Bk horizon:
Texture: gravelly loam, very gravelly loam, gravelly clay loam, very gravelly clay loam
Clay content: 18 to 35 percent
Rock fragments: 15 to 60 percent gravel and cobble
Calcium carbonate equivalent: 2 to 14 percent
ESP: 0 to 15 percent
2CBk horizon:
Hue: 7.5YR to 5Y?
Calcium carbonate equivalent: 2 to 14 percent
ESP: 0 to 15 percent
Reaction: moderately or strongly alkaline
COMPETING SERIES: Currently there are no other series in this family. Similar and related series include the Shrine series which differs in having less than 35 percent coarse fragments.
GEOGRAPHIC SETTING:
Parent material: loamy-skeletal alluvium over sand and gravel derived from mixed sources
Landform: nearly level to steep terraces and alluvial fans
Slopes: 0 to 30 percent
Elevation: 6,700 to 7.200 feet
Mean annual precipitation: at the type location it is about 12 inches with peak periods of precipitation occurring in the spring and early summer months
Mean annual air temperature: about 39 degrees F.
Mean summer air temperature: about 59 degrees F.
Frost-free period: 70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Evanston and Mergel series. The Evanston series differs in having an argillic horizon and in lacking coarse textured IIC horizons. The Mergel series differs in lacking coarse textured IIC horizons above 40 inches.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium to slow. Permeability is moderate.
USE AND VEGETATION: They are used principally as native pastureland or irrigated cropland. Native vegetation includes big sage, Sandberg bluegrass, cactus.
DISTRIBUTION AND EXTENT: Present known distribution limited southern and western Wyoming. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Uinta County, Wyoming 1972. Series name is a coined name.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 10 to 40 inches. (Bk and 2CBk horizons)
Mollic epipedon: The zone from 0 to 9 inches. (A1 and A2 horizons)
Lithologic discontinuity: At the upper boundary of the 2CBk horizon.
The presence of secondary calcium carbonate from 9 to 60 inches. (Bk and 2CBk horizons)
A paper revision and update of the series was made by MO6 August 2000. The classification was changed from Loamy-skeletal, mixed Torriorthentic Haploborolls to Loamy-skeletal over sandy or sandy-skeletal, mixed, superactive, frigid Torriorthentic Haplustolls. Format and horizonation designations were updated. The series has not been updated by the state since 1972.
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomic Version: Second Edition of Soil Taxonomy 1999.