LOCATION JORN OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Vitrandic Argixerolls
TYPICAL PEDON: Jorn cobbly ashy silt loam - on a 4 percent slope, woodland. (Colors are for moist soil unless otherwise noted.)
A--0 to 5 inches; very dark brown (10YR 2/2) cobbly ashy silt loam, grayish brown (10YR 5/2) dry; moderate medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, fine, medium and coarse roots; many very fine, fine, medium and coarse irregular pores; 10 percent cobbles and 5 percent gravel; neutral (pH 7.0); gradual smooth boundary. (3 to 7 inches thick)
Bt1--5 to 12 inches; very dark grayish brown (10YR 3/2) gravelly ashy silty clay loam, grayish brown (10YR 5/2) dry; moderate medium subangular blocky structure; hard, firm, sticky and plastic; many very fine, fine, medium, and coarse roots; many very fine, fine, medium, and coarse tubular pores; common distinct clay films on faces of peds and lining pores; 5 percent cobbles and 10 percent gravel; neutral (pH 7.0); clear smooth boundary. (4 to 10 inches thick)
Bt2--12 to 21 inches; dark brown (10YR 3/3) gravelly silty clay, brown (10YR 5/3) dry; moderate medium prismatic structure parting to moderate medium subangular blocky; very hard, very firm, very sticky and very plastic; common very fine, fine, and few medium and coarse roots; common very fine, fine, and few medium and coarse tubular pores; many prominent clay films on faces of peds and lining pores; 20 percent gravel; neutral (pH 6.8); clear smooth boundary. (7 to 15 inches thick)
2Bt3--21 to 24 inches; dark yellowish brown (10YR 3/4) gravelly silty clay, yellowish brown (10YR 5/4) dry; moderate medium subangular blocky structure; very hard, very firm, sticky and plastic; few very fine and fine roots; few very fine and fine tubular pores; many prominent clay films on faces of peds and lining pores; 15 percent gravel and 50 percent soft gravel size fragments; neutral (pH 6.6); gradual wavy boundary. (3 to 8 inches thick)
2Crt--24 inches; sedimentary bedrock with prominent clay films in fractures.
TYPE LOCATION: Wasco County, Oregon, about 500 feet east and 500 feet north of the SW corner of section 11, T.6 S., R.11 E. (Latitude 45 degrees, 03 minutes, 16 seconds N, Longitude 121 degrees, 23 minutes, 51 seconds W) Warm Springs Indian Reservation.
RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry in all parts of the moisture control section for 60 to 90 consecutive days within the four months that follow the summer solstice. The mean annual soil temperature is 47 to 51 degrees F. Depth to sedimentary bedrock is 20 to 40 inches. The mollic epipedon is 20 to 30 inches thick and includes the upper part of the Bt horizon. Hue is 7.5YR or 10YR. The particle-size control section has 30 to 50 percent field estimated clay with a weighted average of 35 to 45 percent. The upper 7 to 14 inches is estimated to have 10 to 30 percent volcanic glass and 0.4 to 1.0 percent acid oxalate extractable aluminum plus one-half iron.
The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry. It contains 5 to 10 percent gravel and 10 to 20 percent cobbles.
The Bt1 horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry. It is ashy silty clay loam or ashy clay loam with 30 to 40 percent clay. It contains 5 to 15 percent gravel and 5 to 10 percent cobbles.
The 2Bt2 horizon has value of 3 or 4 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry. It is silty clay or clay with 40 to 50 percent clay. It contains 15 to 30 percent gravel and 0 to 5 percent cobbles.
The 2Bt3 horizon has value of 3 or 4 moist, 4 or 5 dry, and chroma of 3 or 4 moist and dry. It is silty clay or clay with 40 to 50 percent clay. It contains 15 to 30 percent gravel and 30 to 50 percent soft gravel size fragments.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Jorn soils are on gently sloping to very steep concave side slopes of mountains. The soil formed in residuum and colluvium derived dominantly from sedimentary rock with an influence of volcanic ash in the surface. Slopes are 2 to 55 percent. Elevations are 2600 to 3500 feet. The climate is characterized by cool and wet winters and hot and dry summers. The mean annual precipitation is 16 to 20 inches. The mean annual temperature is 45 to 49 degrees F. The frost-free period is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boardflower, Bodell, Fawnspring, Littlefawn, Logsprings, and Yawkola soils. Boardflower soils are very deep to bedrock and are on north-facing side slopes of mountains. Bodell soils are loamy-skeletal, shallow to bedrock, and are on adjacent south-facing side slopes. Fawnspring soils are deep to bedrock and are on north-facing side slopes of mountains. Littlefawn soils have an ochric epipedon and are on north-facing side slopes of mountains. Logsprings soils are fine-loamy over clayey, moderately well drained, very deep to bedrock and are on concave areas of adjacent benches. Yawkola soils are clayey-skeletal, deep to bedrock, and are on south-facing side slopes of mountains.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow.
USE AND VEGETATION: These soils are used for timber production, livestock grazing and wildlife habitat. The native vegetation is Ponderosa pine with an understory of antelope bitterbrush, Idaho fescue, and Oregon white oak.
DISTRIBUTION AND EXTENT: North-central Oregon; MLRA 6. The soils of this series are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wasco County (Warm Springs Indian Reservation), Oregon, 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to 21 inches (A, Bt1, and 2Bt2 horizons)
Argillic horizon - The zone from 5 to 24 inches (Bt1, 2Bt2, and 2Bt3 horizons).
Vitrandic feature - The zone from the surface to 12 inches (A and Bt1 horizons).
Particle-size control section - The zone from 5 to 24 inches (Bt1, 2Bt2, and 2Bt3 horizons).