LOCATION KILLPACK UT+COEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Typic Haplocambids
TYPICAL PEDON: Killpack clay loam, cropland. (Colors are for air-dry soil unless otherwise noted.)
Ap--0 to 9 inches; grayish brown (2.5Y 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist; weak medium and fine granular structure; hard, firm, slightly sticky and slightly plastic; common fine roots; common fine pores; strongly calcareous (17 percent calcium carbonate equivalent), carbonates are finely disseminated; slightly alkaline (pH 7.8); clear smooth boundary. (3 to 9 inches thick)
Bw--9 to 23 inches; light brownish gray (2.5Y 6/2) clay loam, grayish brown (2.5Y 5/2) moist; moderate coarse subangular blocky parting to weak fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine roots; few fine pores; strongly calcareous (19 percent calcium carbonate equivalent), carbonates are finely disseminated; slightly alkaline (pH 7.7); gradual wavy boundary. (8 to 21 inches thick)
BCy--23 to 29 inches; light brownish gray (2.5Y 6/2) silty clay loam, grayish brown (2.5Y 5/2) moist; massive; hard, very firm, moderately sticky and moderately plastic; few fine roots; many coarse (5 to 15mm in diameter) gypsum crystals; strongly effervescent (18 percent calcium carbonate equivalent), carbonates are finely disseminated; slightly alkaline (pH 7.7); gradual wavy boundary. (3 to 10 inches thick)
Cr--29 to 39 inches inches; light brownish gray weathered shale bedrock.
TYPE LOCATION: Emery County, Utah; 2 miles northwest of Elmo, northeast of the Elmo road and the Cleveland-Price road; 2,450 feet north and 300 feet east of the SW corner of sec. 30, T. 16 S., R. 10 E.; Elmo USGS quad; lat. 39 degrees 24 minutes 19 seconds N. and long. 110 degrees 51 minutes 5 seconds W., NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture: Soil moisture control section is usually dry, but intermittently moist during late summer and early fall. Aridic moisture regime.
Mean annual soil temperature: 47 to 54 degrees F.
Depth to paralithic contact: 20 to 40 inches to weathered shale. There are few to common gypsum crystals present immediately above the shale.
Clay minerals: mixed but dominantly illite and kaolinite.
The product of the thickness in centimeters and the percent gypsum in all horizons is less than 150.
Particle-size control section:
Clay content: 18 to 35 percent
A horizon:
Hue: 5Y to 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 to 4 dry or moist
Texture: silty clay loam, loam, clay loam
Bw horizon:
Hue: 5Y to 10YR
Value: 5 to 7 dry; 3 to 7 moist
Chroma: 2 to 4 dry or moist
Texture: silt loam, clay loam, silty clay loam
BCy, BC or By horizon:
Hue: 5Y to 10YR
Value: 5 to 7 dry; 3 to 7 moist
Chroma: 2 to 4 dry or moist
Texture: silt loam, silty clay loam, very parachannery clay loam
Rock fragments: 0 to 10 percent gravel
0 to 15 percent shale channers
0 to 60 percent parachanners
COMPETING SERIES: These are the Fordbutte and Sagers series. Fordbutte soils have mean annual soil temperatures of 54 to 57 degrees F.. Sagers soils are deeper than 40 inches to bedrock.
GEOGRAPHIC SETTING: These soils are on gentle sideslopes and baseslopes of rolling shale hills. Slope gradients range from 1 to 25 percent. Killpack soils formed in alluvium from sandstone and shale over residuum from saline marine shale. The climate is semiarid with mean annual temperature of 45 to 52 degrees F. Mean annual precipitation ranges from 5 to 11 inches. Precipitation pattern: wettest months are July to October and driest months are December and June.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chipeta, Persayo, Billings and Libbings soils. Chipeta and Persayo soils are less than 20 inches deep over shale. Billings soils are very deep and developed in alluvium. Libbings soils have salic horizons above a depth of 20 inches.
DRAINAGE AND PERMEABILITY: Well drained; low to high runoff; moderately slow permeability.
USE AND VEGETATION: Cultivated areas are used for grain, alfalfa hay, and irrigated pasture. The remaining areas are used for rangeland. Potential vegetation is shadscale, greasewood, galleta, and gardner saltbush.
DISTRIBUTION AND EXTENT: Eastern Utah and western Colorado. The series is moderately extensive. LRR D, MLRA 34B.
MLRA OFFICE RESPONSIBLE: Lakewood, Colorado
SERIES ESTABLISHED: Emery County, Utah, 1972.
REMARKS:
The pH values were determined of soil paste.
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 10 to 29 inches.
Ochric epipedon: The zone from 0 to 9 inches.
Cambic horizon: The zone from 9 to 29 inches.
Gypsum accumulation: The zone from 23 to 29 inches.
Paralithic contact: The contact with weathered shale at 29 to 39 inches.
For the Killpack series the MAAT is dominantly 45 to 52 degrees F. The Killpack and Fordbutte series overlap in many properties. Further investigation is needed to better define the difference between Killpack and Fordbutte series. As a general characteristic, the Killpack series can have more gypsum than the Fordbutte series.