LOCATION LITTLEFAWN OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Vitrandic Haploxeralfs
TYPICAL PEDON: Littlefawn gravelly loam - on a 20 percent north facing slope, forested. (Colors are for moist soil unless otherwise noted.)
Oi-- 1 inch to 0; organic layer of needles and twigs.
A1-- 0 to 3 inches; dark brown (10YR 3/3) gravelly loam, light brownish gray (10YR 6/2) dry; weak fine and medium granular parting to weak fine platy structure; soft, very friable, nonsticky and nonplastic; common very fine, fine and few medium roots; common very fine and fine tubular pores; 15 percent gravel; neutral (pH 6.8); clear smooth boundary. (3 to 7 inches thick)
A2-- 3 to 10 inches; dark brown (10YR 3/3) gravelly loam, light brownish gray (10YR 6/2) dry; weak very fine and fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine, fine and few medium roots; common very fine and fine tubular pores; 30 percent gravel; slightly acid (pH 6.4); clear smooth boundary. (7 to 10 inches thick)
Bw-- 10 to 17 inches; brown (10YR 4/3) gravelly loam, pale brown (10YR 6/3) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and few medium roots; common very fine and fine tubular pores; 15 percent gravel; slightly acid (pH 6.2); clear smooth boundary. (0 to 8 inches thick)
2Bt1-- 17 to 22 inches; brown (10YR 4/3) gravelly silty clay loam, brown (10YR 5/3) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine and fine roots; few very fine and fine tubular pores; common distinct clay films on faces of peds and lining pores; 30 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (4 to 8 inches thick)
3Bt2-- 22 to 32 inches; dark reddish brown (5YR 3/3) gravelly clay, brown (7.5YR 4/2) dry; massive; extremely hard, extremely firm, very sticky and very plastic; few fine and medium roots; few fine tubular pores; continuous prominent clay films on faces of peds and lining pores; 20 percent gravel; moderately acid (pH 6.0); abrupt wavy boundary. (6 to 10 inches thick)
3Cr-- 32 inches; sedimentary bedrock.
TYPE LOCATION: Wasco County, Oregon: 1000 feet east and 2000 feet north of the SW corner of section 16, T.7 S., R.13 E. (Latitude 44 degrees, 57 minutes, 42 seconds N, Longitude 121 degrees, 11 minutes, 25 seconds W) Warm Springs Indian Reservation.
RANGE OF 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 following the summer solstice. The mean annual soil temperature is 47 to 51 degrees F. Depth to bedrock is 20 to 40 inches. The upper 14 to 20 inches of the solum has 40 to 60 percent volcanic glass and glass aggregate and 15-bar moisture of 8 to 12 percent (air dried). The upper 7 to 14 inches has a phosphate retention of 25 to 35 percent, acid oxalate extractable aluminum plus one-half iron of 0.4 to 1.0 percent. The particle-size control section has 35 to 50 percent clay and 20 to 35 percent rock fragments.
The A horizon has hue of 10YR or 7.5YR, value of 2 or 3 moist, 5 or 6 dry and chroma of 2 or 3 moist and dry. It contains 15 to 30 percent gravel. The moist bulk density is 0.90 to 1.00 g/cc. Organic matter is 4 to 6 percent.
The Bw horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 5 or 6 dry and chroma of 2 or 3 moist and dry. It has 10 to 25 percent clay and 15 to 35 percent gravel. Acid oxalate extractable aluminum plus one-half iron is 0.15 to 0.35 percent.
The 2Bt horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry. It is silty clay loam or clay loam with 35 to 40 percent clay. It has 20 to 35 percent gravel and 0 to 5 percent cobbles.
The 3Bt 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 has 20 to 35 percent gravel and 0 to 5 percent cobbles.
COMPETING SERIES: This is the Boardflower series. Boardflower soils are greater than 60 inches to bedrock.
GEOGRAPHIC SETTING: Littlefawn soils are on gently sloping to steep north-facing side slopes of mountains. Elevations range from 2200 to 3800 feet. Slopes are 2 to 55 percent. The soil formed in residuum and colluvium derived dominantly from sedimentary rock with an influence of volcanic ash in the surface. 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 Fawnspring, Kaskela, Mowako, Mutton, and Wakamo soils. Fawnspring soils are deep to bedrock and on north-facing side slopes of mountains. Kaskela soils are very fine, montmorillonitic., deep to bedrock and are on adjacent rangeland. Mowako soils are loamy-skeletal and are on south-facing side slopes of mountains. Mutton soils are ashy-skeletal, very deep to bedrock and are on adjacent north-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, watershed and wildlife habitat. The native vegetation is ponderosa pine and Douglas fir with an understory of heartleaf arnica, common snowberry, and Oregon white oak.
DISTRIBUTION AND EXTENT: Mutton Mountains of 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 in this pedon include:
Ochric epipedon
Argillic horizon - from 17 to 32 inches (2Bt1, 3Bt2 horizons).
Andic properties - from 0 to 10 inches (A1 and A2 horizons)
Vitrandic feature - from 0 to 17 inches (A1, A2, Bw horizons)
Particle-size control section - from 17 to 32 inches (2Bt1 and 3Bt2 horizons).