LOCATION GRETDIVID COEstablished Series
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Ustic Haplargids
TYPICAL PEDON: Gretdivid loamy coarse sand - rangeland. (Colors are for dry soil unless otherwise indicated.)
A--0 to 3 inches; dark grayish brown (10YR 4/2) loamy coarse sand, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; neutral (pH 7.2); abrupt smooth boundary. (1 to 3 inches thick)
Bt--3 to 7 inches; dark yellowish brown (10YR 4/4) sandy clay loam, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure parting to moderate fine subangular blocky; soft, friable, slightly sticky and slightly plastic; clay films and bridging on sand grains; neutral (pH 7.2); clear smooth boundary. (4 to 7 inches thick).
2BC--7 to 12 inches; light yellowish brown (10YR 6/4) loamy coarse sand, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; loose; mildly alkaline (pH 7.4); clear smooth boundary. (0 to 6 inches thick)
2C1--12 to 52 inches; very pale brown (10YR 7/3) coarse sand, light yellowish brown (10YR 6/4) moist; single grain; loose, nonsticky, and nonplastic; mildly alkaline (pH 7.6); gradual smooth boundary. (5 to 45 inches thick)
2C2--52 to 60 inches; yellow (10YR 7/6) gravelly coarse sand, brownish yellow (10YR 6/6) moist; single grain; loose, nonsticky and nonplastic; 15 percent pebbles; mildly alkaline (pH 7.6).
TYPE LOCATION: Moffat County, Colorado; 16.4 miles northeast of Maybell, 1.5 miles southeast of the intersection of County Road 52 and 6, 1850 feet east and 50 feet north of the southwest corner of Sec. 22, T. 9 N., R. 94 W. Longitude 107 degrees, 56 minutes, 13 seconds west; latitude 40 degrees, 43 minutes, 5 seconds north.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 44 to 47 degrees F. Mean summer soil temperature ranges from 59 to 64 degrees F. Depth to the base of the argillic horizon ranges from 5 to 10 inches. Clay content in the thin Bt ranges from 18 to 27 percent. Coarse fragments in the particle-size control section average less than 15 percent. They are dominantly fine (less than 1/2 inch) pebbles. Pebbles range from 0 to 25 percent in the lower C horizons. Some pedons have discontinuous streaks of visible calcium carbonate in the C horizons.
The A horizon has hue of 10YR or 7.5YR, value of 3 through 5, 2 through 4 moist, and chroma of 1 through 3. Reaction is neutral or mildly alkaline.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 through 6, 3 through 5 moist, and chroma of 4 through 6. It is sandy clay loam or sandy loam. Reaction is neutral or mildly alkaline.
The 2C horizon has hue of 10YR or 2.5Y, value of 6 through 8, 5 through 7 moist, and chroma of 3 through 6. It is coarse sand, gravelly coarse sand, sand, or loamy sand with some medium to very coarse subangular sand grains. Coarse fragments of fine pebbles range from 0 to 25 percent in the lower C horizons.
COMPETING SERIES: These are the Bosler (WY), Millburne (WY), Platoro (CO), Relsob (WY), and the Tigiwon (CO) series. The Bosler, Millburne, and Tigiwon soils have a calcic horizon. In addition, the Bosler, Platoro, and Relsob soils have Bt horizons that extend below 10 inches.
GEOGRAPHIC SETTING: Gretdivid soils are on convex hillslopes and ridgetops at elevations of 6,200 to 7,700 feet. These soils formed in arkosic sandstone residuum. Slopes are 10 to 30 percent. Mean annual precipitation is 11 to 15 inches, and the mean annual temperature is 42 to 45 degrees F. The frost-free period is 75 to 95 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Maysprings soils. Maysprings soils are in a fine-loamy family.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; moderate runoff; moderate permeability.
USE AND VEGETATION: These soils are used primarily for grazing and wildlife habitat. Principle native vegetation is prairie junegrass, Sandberg bluegrass, streambank wheatgrass, western wheatgrass, big sagebrush, needleandthread, bluebunch wheatgrass, and Indian ricegrass.
DISTRIBUTION AND EXTENT: Northwestern Colorado. The series is of moderate extent, or about 12,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Moffat County (Moffat County Area), Colorado, 1991.
REMARKS: The name is coined. Diagnostic features include an ochric epipedon from 0 to 3 inches, and an argillic horizon from 3 to 7 inches. Borollic feature, organic carbon, and soil temperature regime meet the requirements for Borollic. The particle-size control section is 3 to 40 inch zone (Bt, 2BC, 2C1, and part of 2C2 horizons).
The family class was changed in 1990 from "sandy" to fine-loamy over sandy or sandy-skeletal. Last updated by the state 12/90.