LOCATION SUPPAH OREstablished Series
TAXONOMIC CLASS: Ashy-pumiceous, glassy, mesic Vitrixerandic Haplocambids
TYPICAL PEDON: Suppah very paragravelly ashy sandy loam - on a 15 slope at an elevation of 2300 feet, rangeland. (Colors are for moist soil unless otherwise noted.)
A--0 to 3 inches; very dark brown (10YR 2/2) very paragravelly ashy sandy loam, grayish brown (10YR 5/2) dry; weak fine granular structure; soft, friable, nonsticky and nonplastic; many very fine, fine and few medium roots; many very fine, fine and few medium irregular pores; 50 percent pumice gravel and 10 percent 0.5mm to 2.0mm pumice; neutral (pH 6.8); clear smooth boundary. (1 to 3 inches thick)
AB--3 to 10 inches; very dark grayish brown (10YR 3/2) very paragravelly ashy sandy loam, pale brown (10YR 6/3) dry; weak fine and medium subangular blocky structure; soft, friable, nonsticky and nonplastic; many very fine, fine and few medium roots; many very fine, fine and few medium tubular pores; 45 percent pumice gravel and 10 percent 0.5mm to 2.0mm pumice; neutral (pH 7.1); clear smooth boundary. (5 to 10 inches thick)
Bw1--10 to 18 inches; dark grayish brown (10YR 4/2) very paragravelly ashy sandy loam, pale brown (10YR 6/3) dry; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine, fine and few medium roots; many very fine, fine and few medium tubular pores; 55 percent pumice gravel and 15 percent 0.5mm to 2.0mm pumice; neutral (pH 7.3); clear smooth boundary.
Bw2--18 to 26 inches; dark brown (10YR 3/3) extremely paragravelly ashy sandy loam, light yellowish brown (10YR 6/4) dry; moderate fine subangular blocky structure; soft, friable, nonsticky and nonplastic; common very fine, fine and few medium roots; common very fine, fine and few medium tubular pores; slightly effervescent with disseminated lime; 70 percent pumice gravel and 15 percent 0.5mm to 2.0mm pumice; slightly acid (pH 6.5); abrupt wavy boundary. (combined thickness of the Bw horizon is 10 to 28 inches)
C--26 to 60 inches; light gray (10YR 7/2) pumice, very pale brown (10YR 8/2) dry.
TYPE LOCATION: Jefferson County, Oregon, about 2200 feet west and 1400 feet south of the NE corner of section 10, T.10 S., R.12 E. (Latitude 44 degrees, 43 minutes, 13 seconds N, Longitude 121 degrees, 17 minutes, 4 seconds W) Warm Springs Indian Reservation.
RANGE IN CHARACTERISTICS: These soils are usually dry and are dry in all parts of the moisture control section more than half the time (cumulative) that the soil temperature at a depth of 20 inches is above 41 degrees F. The mean annual soil temperature is 52 to 54 degrees F. Solum thickness and depth to fragmental pumice is 20 to 40 inches. The upper part of the solum averages 5 to 15 percent clay, 45 to 80 percent pumice, 30 to 50 percent volcanic glass in the 0.02 to 2.0 mm fraction, 0.2 to 0.4 percent acid oxalate extractable aluminum plus one-half iron, and 8 to 10 percent 15-bar water retention (air-dried sample). Organic matter is 1 to 2 percent in the upper 10 inches of the solum. Soil reaction is slightly acid to neutral.
The A horizon has value of 2 or 3 moist, 5 or 6 dry and chroma of 2 or 3 moist and dry. It contains 45 to 55 percent pumice gravel and 5 to 15 percent 0.5mm to 2.0mm pumice.
The Bw horizon has value of 3 or 4 moist, 6 or 7 dry and chroma of 2 or 3 moist and dry. It is ashy sandy loam or ashy loamy sand. It contains 45 to 80 percent pumice gravel and 10 to 20 percent 0.5mm to 2.0mm pumice.
The C horizon has value of 7 or 8 moist and dry and chroma of 2 or 3 moist and dry. It is fragmental pumice with less than 10 percent (by volume) particles less than 2.0 mm diameter.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Suppah soils are on strongly sloping to moderately steep south-facing foot slopes of canyons. The soil formed in residuum and colluvium derived dominantly from volcanic ash and pumice. Slopes are 12 to 30 percent. Elevations are 1600 to 2800 feet. The climate is characterized by cool and moist winters and hot and dry summers. The mean annual precipitation is 9 to 12 inches. The mean annual temperature is 50 to 52 degrees F. The frost-free period is 110 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bakeoven, Dryhollow, Maupin, Ruckles, Ruclick and Shiva soils. Bakeoven soils are on mesas, loamy-skeletal and very shallow to basalt. Dryhollow soils are on north-facing sideslopes, ashy and very deep to pumice. Maupin soils are on mesas, fine-loamy and moderately deep to a duripan. Ruckles soils are on south-facing side slopes, clayey-skeletal and shallow to basalt. Ruclick soils are on south-facing side slopes, clayey-skeletal and moderately deep to basalt. Shiva soils are on north-facing side slopes, ashy and very deep to pumice.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained. Permeability is moderately rapid.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. Native vegetation is antelope bitterbrush, basin big sagebrush, Idaho fescue, needleandthread, and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: North-central Oregon; MLRA 10. The soils of this series are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Jefferson County (Warm Springs Indian Reservation), Oregon, 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the surface of the soil to 10 inches (A and AB horizons).
Cambic horizon - The zone from 10 to 26 inches (Bw1, Bw2 horizons).
Vitrixerandic feature - the zone from 0 to 26 inches having greater than 35 percent pumice fragments coarser than 2.0mm and 39 to 46 percent volcanic glass and glass aggregate.
Aridic bordering on xeric moisture regime with more than 120 dry days.
Particle-size control section - from 10 to 40 inches with 10 to 26 inches qualifying as ashy-pumiceous (Bw1, and Bw2 horizons) and 26 to 40 inches qualifying as pumiceous. Particle-size class based on thickest layer.
ADDITIONAL DATA: Full laboratory data is available for this soil. Reference sample S91OR-031-103 from Jefferson County, Oregon, NSSL, Lincoln, NE, 2/92.
NSTH 17, RECLASSIFICATION ONLY, 3/95