LOCATION DAMON ORTentative Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive Aquandic Cryaquolls
TYPICAL PEDON: Damon ashy silty clay loam, hayland. (Colors are for moist conditions unless otherwise noted.)
A1--0 to 4 inches; black (10YR 2/1) ashy silty clay loam, gray (10YR 5/1) dry; moderate very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; neutral (pH 7.0); clear smooth boundary. (3 to 6 inches thick)
A2--4 to 13 inches; black (10YR 2/1) ashy silty clay loam, dark gray (10YR 4/1) dry; moderate medium prismatic and strong fine subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; many roots; many very fine tubular pores; neutral (pH 7.0); gradual smooth boundary. (6 to 12 inches thick)
A3--13 to 18 inches; black (10YR 2/1) ashy silty clay loam; moderate medium prismatic and moderate very fine subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; many roots; many very fine tubular pores; neutral (pH 7.0); abrupt irregular boundary. (3 to 6 inches thick)
BA--18 to 26 inches; very dark grayish brown (2.5Y 3/2) silty clay loam; weak coarse prismatic structure; slightly hard, firm, slightly sticky and moderately plastic; common roots; many very fine tubular pores; neutral (pH 6.8); gradual smooth boundary. (6 to 12 inches thick)
Bw1--26 to 38 inches; very dark grayish brown (2.5Y 3/2) silt loam; few fine distinct reddish brown to dark brown redox concentrations; weak coarse prismatic structure; slightly hard, firm, slightly sticky and slightly plastic; few roots, many very fine and few medium and coarse tubular pores; neutral (pH 7.0); gradual smooth boundary. (10 to 14 inches thick)
Bw2--38 to 60 inches; very dark grayish brown (2.5Y 3/2) silt loam, many dark reddish brown (5YR 3/4) redox concentrations; massive; slightly hard, firm, slightly sticky and slightly plastic; few roots; many very fine and few medium and coarse tubular pores; neutral (pH 7.2).
TYPE LOCATION: Grant County, Oregon. 10 miles NW of Seneca. 300 feet east of road and 200 feet south of the Silvies River. SE1/4, SW1/4, sec. 34, T. 15 S., R. 30 E.
RANGE IN CHARACTERISTICS: Depth to bedrock is greater than 60 inches. The control section is a silt loam or silty clay loam and is commonly 25 to 35 percent clay, and less than 15 percent very fine sand or coarser. The soil is saturated from spring to summer. The mean annual soil temperature ranges from 42 to 47 degrees F. and the mean summer temperature ranges from 53 to 59 degrees F. The mollic epipedon is 20 to 40 inches thick.
The A horizon value of 1 or 2 and chroma of 0 to 1 wet. Structure is moderate or strong very fine or fine subangular blocky and moderate or weak medium or coarse prismatic. It has 5 to 20 percent organic matter. It has 5 to 15 percent glass. It has acid oxalate extractable aluminum plus one-half the iron is 0.3 to 0.7.
The C horizon has hue that ranges from 2.5Y to 10YR. When hue is close to 2.5Y, value is 2 or 3, chroma is 2 or less, and distinct mottles occur in the lower part of the mollic epipedon. The mottles may be lacking if chroma is 1 or less and hue is 10YR of redder. The structure is weak coarse prismatic or massive. Some pedons have sand and gravel below 40 inches.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Damon soils are on stream bottoms at elevations of 3,800 to 5,000 feet. Slopes range from 0 to 5 percent. The regolith consists of mixed alluvial sediment, basalt, shale and andesite. The mean annual temperature ranges from 40 to 44 degrees F. The mean January temperature is about 26 degrees F. and the mean July temperature is about 63 degrees F. The mean annual precipitation is 12 to 22 inches. The frost-free period is 10 to 50 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Luckybutte and Silvies soils. Silvies soils are in the fine family. Luckybutte soils have sand and gravel at depths above 40 inches.
DRAINAGE AND PERMEABILITY: Poorly drained. Slow runoff. Slow permeability.
USE AND VEGETATION: Mainly used for meadow hay and pasture. Native vegetation is water-loving grasses, sedges and rushes.
DISTRIBUTION AND EXTENT: Higher elevation valleys and basins of east central Oregon; MLRA 10. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Grant County, Oregon, 1957.
REMARKS: Diagnostic horizons and other features:
Mollic epipedon - 0 to 26 inches