LOCATION LOCKERBY UTEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Ustertic Haplocambids
TYPICAL PEDON: Lockerby silty clay loam - rangeland. (Colors are for air-dry soil unless otherwise noted.)
A--0 to 4 inches; dark grayish brown (10YR 4/2) silty clay loam, brown (10YR 5/3) dry; weak thin platy structure parting to moderate fine granular; slightly hard, friable, sticky and plastic; few fine roots; few fine pores; strongly calcareous; moderately alkaline (pH 8.0); abrupt smooth boundary. (2 to 4 inches thick)
Bw1--4 to 13 inches; brown (10YR 4/3) light silty clay, brown (10YR 5/3) dry; weak medium prismatic structure parting to moderate fine blocky; hard, firm, sticky and plastic; many fine roots; many fine pores; strongly calcareous; moderately alkaline (pH 8.3); clear wavy boundary. (3 to 9 inches thick)
Bw2--13 to 26 inches; brown (10YR 4/3) silty clay, brown (10YR 5/3) dry; weak coarse prismatic structure; extremely hard, firm, very sticky and very plastic; few fine roots; few fine pores; strongly calcareous; moderately alkaline (pH 8.2); clear wavy boundary. (7 to 15 inches thick)
Cy--26 to 38 inches; brown (10YR 4/3) clay, grayish brown (2.5Y 5/2) dry; massive; extremely hard, firm, very sticky and very plastic; few fine roots; few fine pores; very strongly calcareous; many gypsum crystals and filaments; moderately alkaline (pH 8.1); gradual wavy boundary. (8 to 15 inches thick)
Cr--38 inches; shale; high in calcium carbonate and gypsum.
TYPE LOCATION: San Juan County, Utah; about 3,000 feet east and 800 feet south of the SW corner of sec. 6, T. 33 S., R. 25 E.
RANGE IN CHARACTERISTICS:
Soil Moisture: The SMCS is usually dry, in all parts, 105 to 160 cumulative days from April through October. It is usually moist, in some part, 50 to 105 cumulative days during the same period. It is intermittently moist in some part November through April. The period of maximum precipitation is July through October. The soil is driest during May and June. Ustic aridic moisture regime.
Soil Temperature: 47 to 54 degrees F.
Depth to bedrock: 20 to 40 inches
Calcium carbonate content ranges from 10 percent in the upper 13 inches to 30 percent above bedrock.
The soil has cracks to the surface that are 1 to 3.5 cm wide that extend to bedrock.
A horizon
Hue: 10YR or 2.5Y
Value: 3 through 5 moist, 4 or 6 dry
Chroma: 2 to 4.
B horizon
Hue: 10YR or 2.5Y
Value: 4 or 5 moist, 5 or 6 dry
Chroma: 3 or 4
Texture: clay and silty clay
C horizon
Hue: 10YR or 2.5Y
Value: 3 through 6 moist, 5 through 7 dry
Chroma: 1 through 4.
Texture: silty clay or clay but ranges to clay loam or silty clay loam.
Exchangeable sodium percentage (ESP): 5 to 15.
COMPETING SERIES: These are the Heldt (WY), Littlenan (UT), and Razor (CO) series. Heldt soils are very deep. Littlenan soils have hues redder than 10YR. Heldt and Razor soils are in the Western Great Plains LRR-G (MLRA 67) and are more moist in May and June.
GEOGRAPHIC SETTING: Lockerby soils are on hills and ridges at elevations of 5,200 to 7,200 feet. Slopes range from 2 to 15 percent. These soils formed in material weathered from shale. The mean annual air temperature ranges from 45 to 50 degrees F. Average annual precipitation ranges from 10 to 15 inches. The freeze-free period is 100 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hovenweep, Menefee and Ucolo series. Hovenweep soils have hue of 7.5YR or redder and have a calcic horizon. Menefee soils are shallow. Ucolo soils are more than 40 inches deep to bedrock and have mollic epipedons.
DRAINAGE AND PERMEABILITY: Well drained; medium to very high runoff; slow and very slow permeability.
USE AND VEGETATION: These soils are used mainly for range. Potential vegetation is dominantly black sagebrush and western wheatgrass.
DISTRIBUTION AND EXTENT: Southeastern Utah and Northwestern New Mexico. These soils are moderately extensive. LRR-D, MLRA 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: San Juan County, Utah, 1952.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to a depth of about 4 inches. (A horizon)
Cambic horizon - The zone from 4 to about 26 inches. (Bw1, Bw2 horizons)
Classified according to Soil Taxonomy Second Edition, 1999.
ADDITIONAL DATA: Laboratory sample U563155 to U563159 was done by Utah State University Laboratory, July 31, 1957.