LOCATION TROOK WY+UTEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Typic Haplocalcids
TYPICAL PEDON: Trook sandy loam - native grassland (Colors are for dry soil unless otherwise noted.)
A1--0 to 7 inches; pale brown (10YR 6/3) sandy loam, brown (10YR 4/3) moist; moderate fine granular structure; 1/8 to 1/4 inch vesicular crust at surface; soft, very friable; few gravel fragments; calcareous; slightly alkaline, (pH 7.8); clear wavy boundary. (5 to 10 inches thick)
Clca--7 to 12 inches; pale brown (10YR 6/3) gravelly sandy loam, brown (10YR 5/3) moist; very weak subangular blocky structure; soft, very friable; 15 percent gravel fragments; moderate amounts of visible secondary calcium carbonate occurring as concretions and in thin seams and streaks; calcareous; moderately alkaline (pH 8.4); diffuse wavy boundary. (3 to 6 inches thick)
C2ca--12 to 27 inches; very pale brown (10YR 7/3) gravelly loam, pale brown (10YR 6/3) moist; massive; slightly hard, very friable; 20 percent gravel fragments; large amounts of visible secondary calcium carbonate occurring as concretions, in thin seams and streaks, as coatings on sand and gravel fragments, and in finely divided marl-like forms; calcareous, moderately alkaline (pH 8.4); diffuse irregular boundary. (10 to 18 inches thick)
IIC3ca--27 to 42 inches; very pale brown (10YR 8/2) gravelly sandy loam, light gray (10YR 7/2) moist; massive; slightly hard, very friable; 20 percent gravel; large amounts of visible secondary calcium carbonate occurring as concretions in thin seams and streaks, as coatings on the gravel fragments, and in fine marl-like forms; calcareous; strongly alkaline (pH 8.6); diffuse irregular boundary. (10 to 20 inches thick)
C4ca--42 to 60 inches; pale brown (10YR 6/3) gravelly sandy loam, brown (10YR 4/3) moist; massive; slightly hard, very friable; 25 percent gravel; some visible secondary calcium carbonate in the form of concretions, and in thin seams and streaks, or as coatings on the gravel fragments but less than in the horizon above; calcareous; moderately alkaline (pH 8.4). (Several feet thick)
TYPE LOCATION: Fremont County, Wyoming; NE1/4SE1/4 sec. 9, T.4N., R.3E.
RANGE IN CHARACTERISTICS: These soils are typically calcareous at the surface, but they are leached to depths of 1 or 2 inches in some pedons. Depth to the calcic horizon is less than 40 inches. The surface 15 inches averages about .1 to .4 percent organic carbon and the sand/clay ratio ranges from 3 to 16. The 10 to 40 inch control section is typically sandy loam, but clay ranges from 5 to 18 percent, silt from 5 to 35 percent and sand from 50 to 80 percent with more than 35 percent fine sand or coarser; loamy sand is excluded from the preceding ranges. Coarse fragments range from 15 to 35 percent with the content of gravel usually increasing with increasing depth. The mean annual soil temperature is 47 degrees to 52 degrees F. and the mean summer soil temperature is 60 degrees to 68 degrees F. The A1 horizon has hue of 2.5Y through 7.5YR, value of 6 or 7 dry, 4 or 5 moist and chroma of 2 through 5. It usually has granular or crumb structure but has weak subangular blocky structure in some pedons. This horizon is soft or slightly hard. It ranges from slightly to strongly alkaline (pH 7.8 to 8.6). The Cca horizon has hue of 2.5Y through 7.5YR. It is moderately or strongly alkaline (pH 8.0 to 8.8) and contains 15 to 40 percent calcium carbonate equivalent.
COMPETING SERIES: These are the Bluechief, Boreham, Hiko Springs, Kaito, Kinan, McCutchen, Moffat, Nageezi, Nakai, Nakoy, Nolava, Nuahs, Pagina, Riemod, and Wingrock series. Bluespring soils have a lithic contact at 20 to 40 inches. Hiko Springs soils have thin strata of sandy-skeletal material above 40 inches, and have weakly cemented calcic horizons in the sandy-skeletal strata. McCutchen soils have less than 15 percent rock fragments in a major part of the control section, and have a significant component of volcanic ash and pyroclastics. Moffat soils have hue of 5YR or redder and have less than 15 percent rock fragments in a major part of the control section. Pagina soils have a paralithic contact at 20 to 40 inches.
GEOGRAPHIC SETTING: Trook soils are on old alluvial fan surfaces or on high terraces. Typical slope gradients range from 1 to about 10 percent. The soil formed in thick, calcareous, alluvial parent sediment. At the type location, the mean annual precipitation is 7 inches with peak periods of precipitation during the spring and summer months. The mean annual temperature is 44 degrees F., mean summer temperature is 66 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Apron, Saddle, and Worland soils. Apron soils lack a calcic horizon. Saddle soils have an argillic horizon and lack a calcic horizon. Worland soils lack a calcic horizon and have bedrock at depths of less than 40 inches.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate to rapid permeability.
USE AND VEGETATION: These soils are usually used as native pastureland; however, they may be irrigated where water is available. Principal native plants are threadleaf sage, blue grama, needle-and-thread grass, Indian ricegrass, and big sage.
DISTRIBUTION AND EXTENT: Basin areas of central and northern Wyoming. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Fremont County (Riverton Irrigated Area), Wyoming, 1969.
REMARKS: Diagnostic horizons and features:
Ochric epipedon- the zone from the soil surface to 7 inches (A1 horizon).
Calcic horizon - the zone from 7 to 60 inches (Cca horizons).
OSED scanned by NSSQA. Last revised by state on 9/72.