LOCATION STARKEY OREstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic, shallow Typic Argixerolls
TYPICAL PEDON: Starkey very stony silt loam, rangeland. (Colors are for moist soil unless otherwise noted.)
A1--0 to 3 inches; very dark brown (10YR 2/2) very stony silt loam, dark grayish brown (10YR 4/2) dry; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and common fine roots; many very fine tubular pores; 15 percent stones and 20 percent cobbles; neutral (pH 7.2); clear smooth boundary. (2 to 6 inches thick)
A2--3 to 7 inches; very dark brown (10YR 2/2) very cobbly silt loam, dark grayish brown (10YR 4/2) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and common roots, many very fine tubular pores; 50 percent cobbles and 5 percent stones; neutral (pH 7.2); clear smooth boundary. (0 to 5 inches thick)
BA--7 to 9 inches; very dark brown (10YR 2/2) cobbly silty clay, dark grayish brown (10YR 4/2) dry; moderate fine subangular blocky structure parting to weak very fine subangular blocky; hard, friable, moderately sticky and moderately plastic; common very fine roots; many very fine tubular pores; 20 percent cobbles and 10 percent gravel; slightly alkaline (pH 7.4); abrupt smooth boundary. (0 to 5 inches thick)
2Bt1--9 to 12 inches; dark brown (10YR 3/3) gravelly clay, brown (7.5YR 4/3) dry; moderate fine prismatic structure parting to strong fine angular blocky; very hard, very firm, very sticky and very plastic; common very fine roots; common very fine tubular pores; continuous distinct clay films on faces of peds and in pores; 25 percent gravel and 5 percent cobbles; slightly alkaline (pH 7.6); clear smooth boundary. (2 to 4 inches thick)
2Bt2--12 to 15 inches; brown (10YR 4/3) very gravelly clay, brown (10YR 5/3) dry; moderate fine angular blocky structure; very hard, very firm, very sticky and very plastic; common very fine roots; common very fine tubular pores; many distinct clay films on ped faces; 50 percent angular gravel; slightly alkaline (pH 7.6); clear smooth boundary. (3 to 9 inches thick)
2Cr--15 inches; partially weathered volcanic tuff; can be cut with spade with difficulty.
TYPE LOCATION: Union County, Oregon; 4 miles south of town of Hilgard; 15 feet east of Whiskey Creek Road; NW1/4 NW1/4 SW1/4 SE1/4 section 17, T. 3 S., R. 37 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 51 degrees F. Depth to the paralithic contact is 10 to 20 inches. These soils are usually moist but are dry in all parts between depths of 4 and 12 inches for 60 to 80 consecutive days following the summer solstice. The percentage of surface covered with stones and cobbles ranges from about 5 to 15 percent. The mollic epipedon is 7 to 17 inches thick and includes all or a part of the argillic horizon.
The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 1 to 3 moist and dry. It is silt loam with 15 to 27 percent clay. It has 5 to 35 percent stones, 15 to 35 percent cobbles and 0 to 15 percent gravel.
The BA horizon, when present, has colors similar to the A horizon. It is silty clay loam or silty clay with 30 to 45 percent clay. It has 0 to 5 percent stones, 15 to 35 percent cobbles and 0 to 15 percent gravel.
The 2Bt horizon has hue of 7.5YR or 10YR, value of 3 or 4 moist, 4 or 5 dry, and chroma of 3 or 4 moist and dry. It is 50 to 60 percent clay and 35 to 60 percent rock fragments of which 0 to 3 percent are stones, 0 to 10 percent cobbles and 25 to 55 percent gravel.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Starkey soils are on mountains and hills at elevations of 2,400 to 4,000 feet. Slopes range from 2 to 50 percent. The soils formed in colluvium and residuum weathered from volcanic tuff. The surface contains a component of loess. The mean annual precipitation is 12 to 21 inches. The mean annual temperature is 45 to 50 degrees F. The frost-free period is 80 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gwinly, Ukiah and Lookingglass soils. Lookingglass soils are moderately well drained, deeper than 40 inches to bedrock and have less than 35 percent rock fragments. Ukiah soils are moderately deep to a paralithic contact. Gwinly soils are shallow to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: Used for rangeland. Native vegetation is mainly Idaho fescue, bluebunch wheatgrass and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: Northeastern and east-central Oregon; MLRA 9 and 10. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Union County, Oregon, 1978.
REMARKS: Diagnostic horizons and other features:
Mollic epipedon - 0 to 12 inches
Argillic horizon - 9 to 15 inches