LOCATION STUSSI ORTentative Series
TAXONOMIC CLASS: Loamy-skeletal, magnesic, mesic Typic Haploxerolls
TYPICAL PEDON: Stussi gravelly sandy loam - rangeland, on a 39 percent, southwest-facing slope at an elevation of 3,400 feet. (When described on June 3, 2003, the soil was moist in the surface 10 inches and slightly moist below. Colors are for moist soils unless otherwise noted.)
A--0 to 3 inches; very dark gray (10YR 3/1) gravelly sandy loam, gray (10YR 5/1) dry; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; few fine and many very fine roots; few fine and many very fine irregular pores; 10 percent cobbles, 10 percent coarse gravel, and 10 percent fine gravel; moderately alkaline (pH 8.0); abrupt smooth boundary. (2 to 10 inches thick)
AB--3 to 10 inches; very dark grayish brown (10YR 3/2) very cobbly sandy clay loam, grayish brown (10YR 5/2) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; common very fine roots; few fine and common very fine tubular pores; 15 percent cobbles, 15 percent coarse gravel, and 10 percent fine gravel; moderately alkaline (pH 8.0); gradual wavy boundary. (0 to 10 inches thick)
Bw1--10 to 22 inches; very dark grayish brown (10YR 3/2) very gravelly sandy clay loam, grayish brown (10YR 5/2) dry; weak medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine roots; common very fine tubular pores; 5 percent cobbles, 20 percent coarse gravel, and 20 percent fine gravel; moderately alkaline (pH 8.2); gradual wavy boundary.
Bw2--22 to 36 inches; very dark grayish brown (10YR 3/2) very gravelly clay loam, grayish brown (10YR 5/2) dry; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few very fine roots; few very fine tubular pores; 30 percent coarse gravel and 20 percent fine gravel; moderately alkaline (pH 8.2); abrupt wavy boundary. (Combined thickness of the Bw horizon is 16 to 30 inches.)
R--36 inches; strongly cemented serpentinitic bedrock.
TYPE LOCATION: Grant County, Oregon, 2004, located about 3.5 miles NE of the town of Mt. Vernon on the north side of Highway of 395; 1,600 feet east and 500 feet north of the SW corner of section 12, T. 13 S., R. 30 E. (Latitude 44 degrees, 26 minutes, and 53.42 seconds N. and Longitude 119 degrees, 03 minutes, and 20.70 seconds W.)
RANGE IN CHARACTERISTICS: The moisture control section is usually dry in all parts for 70 to 90 consecutive days following the summer solstice. The mean annual temperature is 47 to 52 degrees F. Depth to bedrock is 20 to 40 inches. The particle size control section averages 35 to 60 percent rock fragments and 18 to 30 percent clay. The mollic epipedon is 10 to 20 inches. Mollic colors continue below 20 inches but are the result of the color of the rock (lithochromic). Organic matter also declines below 1 percent below 20 inches. Soil reaction is slightly or moderately alkaline throughout.
The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 1 or 2 moist and dry. It is sandy loam with 10 to 20 percent clay. The subsurface layers are sandy loam, sandy clay loam, or loam with 15 to 25 percent clay. It has 5 to 15 percent cobbles, 10 to 20 percent coarse gravel, and 5 to 15 percent fine gravel.
The Bw horizon has value of 3 or 4 moist, 5 or 6 dry, and chroma of 1 or 2 moist and dry. It is sandy loam, sandy clay loam, or clay loam with 18 to 30 percent clay. It has 0 to 10 percent cobbles, 20 to 30 percent coarse gravel, and 15 to 25 percent fine gravel.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Stussi soils are on sideslopes of hills and have slopes of 20 to 50 percent. They formed in loamy colluvium derived from serpentinitic rock. Elevations are 3,000 to 4,600 feet. The climate is characterized by cool wet winters and hot dry summers. The mean annual precipitation is 12 to 18 inches, and the mean annual temperature is 45 to 50 degrees F. The frost-free period is 80 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ateron, Belshaw, Finsel, Grell, Tub, and Waterbury soils. Ateron soils are found on basalt benches and plateaus above serpentine exposures, frigid, clayey-skeletal, and are shallow bedrock. Belshaw soils are on adjacent south slopes, very deep over weathered tuffs, and are in the fine family. Finsel soils are on north slopes, frigid, and are clayey-skeletal. Grell soils are found on sideslopes in complex with Stussi and are shallow to serpentine bedrock. Tub soils are on north slopes, very deep to weathered tuffs, and are in the fine family. Waterbury soils are found on sideslopes of basalt flows located above serpentine exposures, are shallow to bedrock, and are clayey-skeletal.
DRAINAGE AND PERMEABILITY: Well drained. Moderately slow permeability.
USE AND VEGETATION: Livestock grazing and wildlife habitat. The potential native vegetation is bluebunch wheatgrass, Thurbers needlegrass, needleandthread, and sand dropseed.
DISTRIBUTION AND EXTENT: East-central Oregon. MLRA B-10. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Grant County, Oregon, 2004. The name is derived from Stussi Creek located about 6 miles west of the town of Long Creek.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from the surface to 10 inches (A and AB horizons)
Cambic horizon - from 10 to 36 inches (Bw1 and Bw2 horizons)
Particle size control section - from 10 to 36 inches (Bw1 and Bw2 horizons)
Xeric moisture regime
ADDITIONAL DATA: Partial lab data will be available for this soil. Reference sample is S03OR-23-009 was collected from Grant County and sent to the NSSL in Lincoln, NE during 12/03.