LOCATION GRENET OREstablished Series
TAXONOMIC CLASS: Ashy-skeletal, glassy, frigid Typic Vitrixerands
TYPICAL PEDON: Grenet very gravelly sandy loam - on a 25 percent south facing slope, woodland. (Colors are for moist soils unless otherwise noted.)
0i-- 1 inch to 0; organic layer of needles and twigs.
A-- 0 to 4 inches; dark grayish brown (10YR 4/2) very gravelly sandy loam, light brownish gray (10YR 6/2) dry; moderate medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, and few medium and coarse roots; many very fine, fine, and few medium and coarse irregular pores; 35 percent gravel; strongly acid (pH 5.4); clear wavy boundary. (4 to 6 inches thick)
AB-- 4 to 12 inches; grayish brown (10YR 5/2) very gravelly sandy loam, light gray (10YR 7/2) dry; moderate fine subangular blocky parting to weak medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine and few medium and coarse roots; many very fine, fine, and few medium and coarse tubular pores; 50 percent gravel; strongly acid (pH 5.4); clear smooth boundary. (0 to 10 inches thick)
Bw1-- 12 to 21 inches; grayish brown (10YR 5/2) extremely gravelly sandy loam, white (10YR 8/1) dry; weak fine subangular blocky structure; soft, friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine tubular pores; 60 percent gravel and 5 percent cobbles; strongly acid (pH 5.2); clear smooth boundary. (7 to 9 inches thick)
Bw2-- 21 to 36 inches; light brownish gray (10YR 6/2) extremely gravelly loamy sand, white (10YR 8/1) dry; weak fine subangular blocky structure; soft, friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine tubular pores; 70 percent gravel and 5 percent cobbles; strongly acid (pH 5.4); clear smooth boundary. (9 to 15 inches thick)
Cr-- 36 inches; tuff.
TYPE LOCATION: Wasco County, Oregon; 2500 feet east and 2000 feet north of the SW corner of section 20, T.6 S., R.10 E. (Warm Springs Indian Reservation).
RANGE OF CHARACTERISTICS: These soils are usually moist but are dry in all parts of the moisture control section for 45 to 60 consecutive days within the four months that follow the summer solstice. The mean annual soil temperature is 43 to 45 degrees F. Depth to volcanic tuff is 20 to 40 inches. Hue is 7.5YR or 10YR. The particle-size control section has 10 to 18 percent clay and 35 to 80 percent rock fragments. Phosphate retention is 30 to 65 percent and acid oxalate aluminum plus 1/2 iron is between 0.5 and 1.5 percent in the less than 2.0mm fraction. There is 30 to 50 percent volcanic glass and glass aggregate in the 0.02 to 2.0 mm fraction. The 15-bar moisture is less than 15 percent on air dried samples and less than 30 percent on undried samples. Grenet soils have a moist bulk density of 0.80 to 0.90g/cc.
The A horizon has a value of 3 or 4 moist, 5 or 6 dry and chroma of 1 or 2 moist and dry. It has 35 to 50 percent gravel.
The Bw horizon has value of 5 or 6 moist, 7 or 8 dry and chroma of 1 or 2 moist and dry. It is sandy loam or loamy sand with 50 to 70 percent gravel and 0 to 10 percent are cobbles.
COMPETING SERIES: These are the Doe (T), Kusu (T), Pettijohn, Stices, Twelvemile, and Yallani soils. Doe and Pettijohn soils are very deep. Kusu soils average over 18 percent clay in the particle-size control section and are deep to a lithic contact. Stices soils are very deep to bedrock. Twelvemile soils are very deep to bedrock and are dry for 60 to 100 consecutive days. Yallani soils are very deep to bedrock, dry for more than 60 consecutive days, and have a P-retention of more than 85 percent.
GEOGRAPHIC SETTING: Grenet soils are on nearly level to very steep south-facing side slopes of mountains. Elevations range from 2800 to 4600 feet. Slopes are 0 to 65 percent. The soil formed in residuum and colluvium derived from volcanic tuff with an influence of volcanic ash. The climate is characterized by cold and wet winters and hot and dry summers. The mean annual precipitation is 30 to 40 inches, the mean annual temperature is 41 to 43 degrees F. and the frost-free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kusu and Pipp soils. Kusu soils are well drained and deep to unweathered volcanic tuff. Pipp soils are deep to unweathered andesite.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained. Permeability is rapid.
USE AND VEGETATION: These soils are used for timber production, livestock grazing, watershed and wildlife habitat. The native vegetation is ponderosa pine, Douglas fir and grand fir with an understory of snowbrush ceanothus, common snowberry, golden chinkapin, and starflower.
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 in this pedon include:
Ochric epipedon
Cambic horizon - from 12 to 36 inches (Bw1, Bw2 horizons)
Andic properties - from the surface to 36 inches (A, AB, Bw1, and Bw2 horizons).
Particle-size control section - from the surface to 36 inches. (A, AB, Bw1, Bw2 horizons).
Ashy-skeletal family - more than 30 percent volcanic glass and glass aggregate and 62 percent rock fragments (calculated).
Phosphate retention, acid oxalate aluminum and iron, volcanic glass and 15-bar moisture is based on laboratory analysis from similar soils.