LOCATION EGGLESON OREstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, frigid Oxyaquic Haploxerolls
TYPICAL PEDON: Eggleson gravelly loam, 0 to 2 percent slopes, pasture. (Colors are for moist soil unless otherwise noted.)
A--0 to 3 inches; very dark brown (10YR 2/2) gravelly loam, very dark grayish brown (10YR 3/2) dry; strong fine granular structure; soft, friable, nonsticky and nonplastic; many very fine roots; many very fine irregular pores; 20 percent gravel; slightly acid (pH 6.4), clear smooth boundary. (2 to 6 inches thick)
AC--3 to 10 inches; very dark grayish brown (10YR 3/2) very gravelly sandy loam, dark grayish brown (10YR 4/2) dry; weak very fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine roots; many very fine and fine irregular pores; 40 percent gravel and 15 percent cobbles; neutral (pH 6.6); clear wavy boundary. (6 to 10 inches thick)
C1--10 to 17 inches; very dark grayish brown (10YR 3/2) extremely gravelly loamy sand, dark grayish brown (10YR 4/2) dry; single grain; loose, nonsticky and nonplastic; common very fine roots; many very fine irregular pores; 50 percent gravel and 20 percent cobbles; neutral (pH 7.0); gradual wavy boundary. (5 to 10 inches thick)
C2--17 to 30 inches; multicolored extremely gravelly sand; single grain; loose, nonsticky and nonplastic; few fine roots; 50 percent gravel and 20 percent cobbles; slightly alkaline (pH 7.4); gradual wavy boundary. (10 to 20 inches thick)
C3--30 to 60 inches; multicolored extremely gravelly sand; single grain; loose, nonsticky and nonplastic; common medium distinct dark yellowish brown (10YR 4/4) masses of iron accumulation and redoximorphic concentrations; 20 percent cobbles and 50 percent gravel; slightly alkaline (pH 7.4).
TYPE LOCATION: Wallowa County, Oregon; about 1 mile south of Enterprise, Oregon; 1,400 feet north and 1,200 feet west of the SE corner of section 2, T. 2 S., R. 44 E.
RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry in all parts of the moisture control section for 60 to 90 consecutive days during the summer. The mean annual soil temperature is 44 to 47 degrees F. The depth to bedrock is greater than 60 inches. The thickness of the mollic epipedon is 10 to 15 inches and the organic matter content of the mixed upper 10 inches is estimated to be more than 1 percent and decreases irregularly with depth. The depth to a high water table is 2 to 3 feet during the spring. The particle-size control section has less than 5 percent clay, more than 50 percent fine sand and coarser, and more than 60 percent rock fragments.
The A and AC horizons have value of 2 or 3 moist, 3 to 5 dry, and chroma of 1 or 2 moist and dry. The A horizon is loam with 10 to 15 percent clay. The AC horizon is sandy loam with 5 to 10 percent clay. Rock fragments range from 15 to 30 percent gravel and 0 to 3 percent cobbles in the A horizon and 35 to 55 percent gravel and 0 to 15 percent cobbles in the AC horizon. The A horizon is slightly acid or neutral.
The C1 horizon has value of 3 or 4 moist, 4 or 6 dry, and chroma of 1 to 3 moist and dry. The C2 and C3 horizons are multicolored. Texture is loamy sand or sand with 0 to 5 percent clay. It has 40 to 50 percent gravel, 20 to 30 percent cobbles, and 0 to 10 percent stones. Redox concentations are few or common, fine or medium, and faint or distinct in the lower part of the C horizon and within a depth of 30 to 40 inches. Soil reaction is neutral or slightly alkaline.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Eggleson soils are on flood plains. They formed in mixed alluvium. Slope is 0 to 2 percent. Elevation is 3,400 to 4,400 feet. The climate is characterized by cold wet winters and hot dry summers. The mean annual precipitation is 13 to 17 inches. The mean annual temperature is 42 to 45 degrees F. The mean frost-free period is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cheval, Josset, Matterhorn, and Sturgill soils. The Cheval and Josset soils are coarse-loamy over sandy or sandy-skeletal and are on floodplains. The Matterhorn soils are somewhat excessively drained, have a calcic horizon, and are on adjacent fan terraces. The Sturgill soils are fine-silty, poorly drained, and are on flood plains.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderate permeability in the surface horizon and rapid below. These soils are subject to rare flooding and have a high water table at a depth of 2 to 3 feet during the spring.
USE AND VEGETATION: These soils are used mainly for timber production, pasture, and homesite development. The native vegetation is Engleman spruce, black cottonwood, Ponderosa pine, Rocky mountain juniper, water birch, rose, sedge, and willow.
DISTRIBUTION AND EXTENT: Northeastern Oregon; MLRA 9. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wallowa County, Oregon, 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from the surface to 10 inches (A and AC horizons) with more than 1 percent organic matter
Fluventic feature - an irregular decrease in organic carbon with increasing depth
Particle-size control section - 10 to 40 inches average 70 percent rock fragments and more than 50 percent fine sand and coarser