LOCATION GOURLEY CO
Established Series
Rev. WPT/GB/SJJ
06/2016
GOURLEY SERIES
The Gourley series consist of very deep, well drained soils that formed in alluvium and colluvium from interbedded shale and limestone. These soils are on intermediate plateau levels, valley side slopes, small swales and toe slopes. Slopes range from 1 to 45 percent. The mean annual precipitation is about 23 inches and the mean annual temperature is about 40 degrees F.
TAXONOMIC CLASS: Fine, smectitic Vertic Argicryolls
TYPICAL PEDON: Gourley clay loam - Mountain grass park. (Colors are for dry soil unless otherwise noted.)
A--0 to 5 inches; dark gray (10YR 4/1) clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular and crumb structure; few cracks 1/2 to 3/4 inch wide; soft, very friable, slightly sticky, and slightly plastic; neutral; clear smooth boundary. (4 to 8 inches)
BA--5 to 13 inches; dark grayish brown (10YR 4/2) heavy clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse subangular blocky structure; few cracks 1/2 to 3/4 inch wide; hard, friable, sticky, and plastic; few thin clay films on ped faces; neutral; clear smooth boundary. (6 to 12 inches)
Bt--13 to 28 inches; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; moderate coarse and very coarse prismatic structure parting to strong angular and subangular blocky, with wedge-shaped aggregates in the lower parts; common cracks 1/2 to 3/4 inch wide; hard, firm, sticky, and plastic; many faint clay films on ped faces; neutral; clear wavy boundary. (10 to 28 inches)
Bk--28 to 36 inches; grayish brown (10YR 5/2) light clay, dark grayish brown (10YR 4/2) moist; weak very coarse prismatic structure parting to moderate and coarse angular and subangular blocky; few cracks 1/2 inch wide; hard, firm, sticky, and plastic; common faint clay films on ped faces; weakly effervescent; slightly alkaline; clear wavy boundary. (6 to 10 inches)
C--36 to 60 inches; grayish brown (10YR 5/2) clay loam, brown (10YR 4/3) moist; massive; hard, firm, sticky, and plastic; weakly effervescent; slightly alkaline.
TYPE LOCATION: Rio Blanco County, Colorado; about 1,150 feet east, 250 feet south of the northwest corner of Sec. 12, T. 1 N., R. 90 W. Lost Park, Colorado quad.; Latitude 40 degrees, 4 minutes, 30 seconds N.; and longitude 107 degrees, 26 minutes, 45 seconds W.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 39 to 44 degrees F. Mean summer soil temperature ranges from 47 to 54 degrees F. The particle-size control section is typically clay or silty clay with clay ranging from 40 to 55 percent. Rock fragments range from 0 to 25 percent and are dominately less than one and one-half inches in size but large channers and flaggy fragments also occur. Depth to uniformly calcareous material ranges from 20 to 40 inches. Reaction ranges from neutral to moderately alkaline. Thickness of the mollic epipedon ranges from 7 to 15 inches and the depth to the base of the Bt horizon ranges from 20 to 48 inches.
The A and BA horizons have hue of 5Y through 7.5YR, value of 4 or 5, 2 or 3 moist, and chroma of 1 through 3. Textures are clay loam or silty clay loam.
The Bt and Bk horizons have hue of 5Y through 7.5YR, value of 4 through 6, 3 through 6 moist, and chroma of 2 through 6. Textures are clay or silty clay.
The C horizon has hue of 5Y through 7.5YR, values of 4 through 6, 3 through 6 moist, and chroma of 2 through 6. Textures are clay, clay loam or silty clay loam.
COMPETING SERIES: These are the
Cimarron (CO),
Cucharas (CO), and the
Winridge (ID) series. Cimarron soils are noncalcareous to depths of 40 inches or more. The Winridge series has lithic bedrock a depths of 20 to 40 inches. The Cucharas soils have a paralithic contact at 20 to 40 inches.
GEOGRAPHIC SETTING: Gourley soils are on intermediate plateau levels, valley side slopes, small swales and toe slopes. Slopes range from 1 to 45 percent. The soils formed in mixed alluvium and colluvium mainly from sedimentary shale and limestone. Elevation ranges from 8,300 to 10,200 feet. The mean annual precipitation is 18 to 25 inches with most being received as snow. The mean annual temperature ranges from 34 to 42 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Gothic,
Judy,
Mayoworth and
Starley soils. Gothic soils are noncalcareous to a depth greater than 40 inches and do not crack excessively. Judy and Mayoworth soils have bedrock at depths of 20 to 40 inches. Starley soils have bedrock at depths of 10 to 20 inches.
DRAINAGE AND PERMEABILITY: Well-drained; slow to rapid runoff; slow permeability.
USE AND VEGETATION: Gourley soils are used for summer grazing of livestock, wildlife habitat, and for limited recreation. Native vegetation include open areas of subalpine grasses and low shrubs.
DISTRIBUTION AND EXTENT: Mountainous areas of Western Colorado. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Rio Blanco County, (Flat Tops Soil Survey Area), Colorado, 8/84.
REMARKS: This series, in the 4/83 revision, documented a change in type location from San Miguel County, Colorado, to Rio Blanco County, Colorado. Diagnostic features include a mollic epipedon from 0 to 13 inches, an argillic horizon from 13 to 28 inches, and vertic properties from 13 to 28 inches, and a cryic temperature regime. Last updated by the state 4/95.
National Cooperative Soil Survey
U.S.A.