LOCATION PIUMPSHA           OR
Established Series
Rev. TMP/RWL
03/98

PIUMPSHA SERIES


The Piumpsha series consists of very deep, well drained soils on mountains. They formed in residuum and colluvium derived from andesite with a mantle of volcanic ash. Slopes are 2 to 40 percent. The mean annual precipitation is about 95 inches and the mean annual temperature is about 35 degrees F.

TAXONOMIC CLASS: Medial, amorphic Alfic Vitricryands

TYPICAL PEDON: Piumpsha gravelly sandy loam - on a 15 percent slope, woodland. (Colors are for moist soil unless otherwise noted.)

Oi--2 inches to 0; organic layer of needles and twigs

A1--0 to 5 inches; very dark brown (10YR 2/2) gravelly sandy loam, dark brown (10YR 4/3) dry; weak fine granular structure; soft, friable, nonsticky and nonplastic; many very fine, fine and common medium and coarse roots; many very fine, fine and common medium and coarse irregular pores; 15 percent gravel; moderately acid (pH 6.0); clear smooth boundary.

A2--5 to 8 inches; dark brown (10YR 3/3) gravelly sandy loam, yellowish brown (10YR 5/4) dry; weak fine subangular blocky structure parting to weak very fine and fine granular; soft, friable, nonsticky and nonplastic; common very fine, fine, medium and few coarse roots; common very fine, fine and medium tubular pores; 15 percent gravel; moderately acid (pH 6.0); clear smooth boundary. (Combined thickness of the A horizon is 8 to 16 inches)

Bw1--8 to 22 inches; dark yellowish brown (10YR 3/4) gravelly sandy loam, yellowish brown (10YR 5/4) dry; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine, fine and few medium roots; common very fine, fine and few medium tubular pores; 15 percent gravel; moderately acid (pH 6.0); clear wavy boundary.

Bw2--22 to 27 inches; dark yellowish brown (10YR 3/4) gravelly sandy loam, light yellowish brown (10YR 6/4) dry; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine tubular pores; 20 percent gravel and 5 percent cobbles; moderately acid (pH 6.0); clear smooth boundary. (Combined thickness of the Bw horizon is 15 to 26 inches)

2Bt1--27 to 43 inches; dark brown (10YR 4/3) gravelly loam, light yellowish brown (10YR 6/4) dry; moderate medium and coarse subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; common faint clay films on faces of peds and lining pores; 15 percent gravel; moderately acid (pH 6.0); clear smooth boundary.

2Bt2--43 to 60 inches; dark brown (10YR 4/3) gravelly clay loam, yellowish brown (10YR 5/4) dry; moderate and coarse subangular blocky structure; hard, firm, sticky and plastic; common very fine and few fine roots; common very fine and few tubular pores; common distinct clay films on faces of peds and lining pores; 20 percent gravel; moderately acid (pH 6.0).

TYPE LOCATION: Jefferson County, Oregon, about 1500 feet west and 2500 feet south of the NE corner of section 29, T. 10 S., R. 9 E. (Warm Springs Indian Reservation). (Latitude 44 degrees, 40 minutes, 25 seconds N, Longitude 121 degrees, 41 minutes, 3 seconds W)

RANGE OF CHARACTERISTICS: These soils are usually moist and are not dry in all parts of the moisture control section for as long as 45 consecutive days in the four months that follow the summer solstice. The mean annual soil temperature is 36 to 38 degrees F. Depth to bedrock and solum thickness is 60 inches or more. The particle-size control section averages less than 35 percent total rock fragments and has 10 to 15 percent clay in the upper part and 20 to 30 percent clay in the lower part. P-retention is more than 85 percent and acid oxalate extractable aluminum plus one-half of the acid oxalate extractable iron is 3 to 5 percent in the less than 2.0mm fraction. The 15-bar water is 12 to 15 percent on air-dry samples.

The A horizon has value of 2 or 3 moist, 4 or 5 dry and chroma of 2 or 3 moist and 3 or 4 dry. There is 20 to 40 percent volcanic glass and glass aggregate in the 0.02 to 2.0mm fraction. It is gravelly sandy loam or very bouldery sandy loam. It has 15 to 25 percent gravel and 0 to 30 percent boulders.

The Bw horizon has value of 3 or 4 moist, 5 or 6 dry and chroma of 3 or 4 moist and dry. It has 15 to 35 percent gravel and 0 to 10 percent cobbles.

The 2Bt horizon has value of 3 or 4 moist, 5 or 6 dry and chroma of 3 and 4 moist and dry. It is gravelly loam gravelly clay loam, or very gravelly clay loam with 15 to 40 percent gravel and 0 to 10 percent cobbles. The soil reaction is moderately acid to strongly acid.

COMPETING SERIES: These are no competing series.

GEOGRAPHIC SETTING: Piumpsha soils are on nearly level to moderately steep uplands. Elevations are 4200 to 6400 feet. Slopes are 2 to 40 percent. The soil formed in residuum and colluvium derived from andesite with a mantle of volcanic ash. The mean annual precipitation is 80 to 110 inches. The mean annual temperature is 34 to 36 degrees F. The frost-free period is 10 to 30 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Jojo, and Pinhead soils. Jojo soils are medial-skeletal and moderately deep to bedrock. Pinhead soils are medial-skeletal.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate.

USE AND VEGETATION: These soils are used for watershed and wildlife habitat. The native vegetation is lodgepole pine, subalpine fir, mountain hemlock, and western white pine with an understory of grouse blueberry, common beargrass and big huckleberry.

DISTRIBUTION AND EXTENT: North-central Oregon; MLRA A3. The soils of this series are not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Warm Springs Indian Reservation, Jefferson County, Oregon, 1993.

REMARKS: Diagnostic horizons and features recognized in this pedon include:

Ochric epipedon

Andic soil properties - from the surface to 60 inches. Acid oxalate extractable aluminum plus one-half of the acid oxalate extractable iron is 3.6 to 4.8 percent, P-retention is 92 to 94 percent and volcanic glass is 5 percent from 8 to 43 inches, based on lab data.

Cambic horizon - from 8 to 27 inches (Bw1 and Bw2 horizons).

Argillic horizon - from 27 to 60 inches (2Bt1 and 2Bt2 horizons).

Particle-size control section - from the surface to 40 inches (A1, A2, Bw1, Bw2 horizons and upper 13 inches of the 2Bt1 horizon).

Medial family - andic soil properties from surface to 40 inches with 15-bar water on air-dry sample of 12.5 to 15.3 percent.

ADDITIONAL DATA: Partial lab data available for this soil. Reference pedon # 91P255 from Jefferson County, Oregon, NSSL, Lincoln, NE, 5/91.


National Cooperative Soil Survey
U.S.A.