LOCATION ALECANYON WAEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Vitrandic Haploxerolls
TYPICAL PEDON: Alecanyon very cobbly ashy fine sandy loam - rangeland on a 5 percent southeast facing slope at 2,440 feet elevation. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures.)
A--0 to 12 inches; dark grayish brown (10YR 4/2) very cobbly ashy fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; common very fine irregular pores; 10 percent sand-size pumice, 0.5 to 2.0 mm. in diameter; 25 percent gravel and 30 percent cobbles; neutral (pH 7.0); abrupt smooth boundary. (10 to 20 inches thick)
2AB--12 to 22 inches; brown (10YR 5/3) extremely gravelly loamy coarse sand, dark brown (10YR 3/3) moist; single grain; loose, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine irregular pores; 5 percent sand-size pumice, 0.5 to 2.0 mm. in diameter; 35 percent gravel and 30 percent cobbles; neutral (pH 7.2); gradual smooth boundary. (3 to 10 inches thick)
2Bq1--22 to 31 inches; yellowish brown (10YR 5/4) extremely cobbly loamy coarse sand, dark brown (10YR 3/3) moist; single grain; loose, nonsticky and nonplastic; many very fine and common fine roots; many fine and medium interstitial pores; common distinct very pale brown (10YR 8/3) dry silica coatings on underside of gravel and cobbles; 35 percent gravel and 35 percent cobbles; neutral (pH 7.2); gradual smooth boundary.
2Bq2--31 to 60 inches; extremely gravelly multicolored coarse sand; single grain; loose, nonsticky and nonplastic; many fine interstitial pores; common distinct and prominent very pale brown (10YR 8/3) dry coatings of silica on the undersides of gravel and cobbles; 40 percent gravel and 35 percent cobbles: neutral (pH 7.2). (Combined thickness of the 2Bq horizons is 20 to 40 inches.)
TYPE LOCATION: Douglas County, Washington; about 8 miles west and 4 miles north of the town of Grand Coulee; 2,900 feet north and 400 feet west of the southeast corner of section 10, T. 29 N., R. 29 E. (Latitude 48 degrees 01 minutes, 41 seconds N., Longitude 119 degrees 08 minutes, 53 seconds W.)
RANGE IN CHARACTERISTICS: The average annual soil temperature is 48 to 52 degrees F. These soils are usually moist in the moisture control section but are dry for 90 to 105 days consecutive days following the summer solstice. Thickness of the mollic epipedon is 10 to 20 inches. The mollic epipedon (A horizon) has an estimated moist bulk density of 1.10 to 1.35 g/cc, volcanic glass content of 20 to 50 percent, including 10 to 15 percent sand-size pumice, 0.5 to 2.0 mm. in diameter, acid-oxalate extractable aluminum plus one half of the acid-oxalate extractable iron of 0.15 to 0.40, 15-bar water retention of 5 to 10 percent and field estimated 3 to 12 percent clay. One or more subhorizons in the top 30 inches of the profile, including the surface horizon in all cases, has less than 75 percent base saturation by sum of cations.
The particle-size control section has 45 to 70 percent rock fragments and apparent estimated field clay of 1 to 8 percent. Depth to sandy-skeletal glacial outwash ranges from 10 to 20 inches.
The A horizon has value of 4 or 5 dry and chroma of 2 or 3 moist. Rock fragments in the form of gravel and cobbles average 35 to 60 percent. There is 10 to 15 percent sand-size pumice, 0.5 to 2.0 mm. in diameter.
The 2AB horizon has value of 5 or 6 dry. Sand-size pumice less than 2 mm in size that ranges from 0 to 10 percent. Rock fragments in the form of gravel and cobbles range from 35 to 65 percent. Texture is a very cobbly coarse sand, very gravelly loamy coarse sand, extremely gravelly loamy coarse sand or extremely cobbly loamy coarse sand. Reaction is neutral to slightly alkaline.
The 2Bq horizon has 50 to 75 percent rock fragments. Texture is a very cobbly coarse sand, extremely cobbly loamy coarse sand, extremely cobbly coarse sand, very gravelly coarse sand, or extremely gravelly coarse sand. Silica coatings on the underside of rock fragments range from few to many and distinct to prominent. Calcium carbonate equivalent is estimated to range from 0 to 3 percent. Reaction is neutral to slightly alkaline.
COMPETING SERIES: These are the Owhi (T) and Sequim series. Sequim soils are dry for 75 to 90 days and are west of the Cascade Mountains. Owhi soils lack the silica coatings in the subsoil horizons.
GEOGRAPHIC SETTING: Alecanyon soils are on glacial outwash terraces, eskers and moraines on upland plateaus. These soils formed in glacial outwash, a mixture of loess, volcanic ash and pumice. Elevations are 1,000 to 3,100 feet. Slopes are 0 to 65 percent. The climate is characterized by warm, dry summers and cool, moist winters. Average annual precipitation ranges from 12 to 17 inches. Average January temperature is about 26 degrees F.; average July temperature is about 70 degrees F., and average annual air temperature is 47 to 50 degrees F. Frost-free season is 110 to 165 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cachebutte, and Nemire soils. Cachebutte soils are on glacial outwash plains and are moderately deep to glacial outwash. Nemire soils are in drainageways and are non-skeletal.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; moderately rapid permeability above the glacial outwash; very rapid through the outwash.
USE AND VEGETATION: Livestock grazing and crop production. Winter wheat and barley are the principle crops. Potential natural vegetation is bluebunch wheatgrass, Thurber needlegrass, fleabane, buckwheat, thretip sagebrush and Wyoming big sagebrush.
DISTRIBUTION AND EXTENT: Douglas County, Washington; MLRA's 8 and 9. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Douglas County, Washington, 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 12 inches (A horizon) with mollic colors from 12 to 31 inches but less than 0.6 percent organic carbon.
Particle-size control section - the zone from 10 to 40 inches with 10 to 12 inches loamy-skeletal (greater than 50 percent fine sand or coarser) and 12 to 40 inches sandy-skeletal. The weighted average of rock fragments is 71 percent.
ADDITIONAL DATA: Partial NSSL lab data is available for this pedon NSSL pedon number 90P0346 (Sample # S90WA-017-005), Lincoln, NE.