LOCATION MCCOIN OREstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Aridic Haploxerolls
TYPICAL PEDON: McCoin loam, cultivated. (Colors are for dry soil unless otherwise noted.)
A1--0 to 2 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; 5 percent pebbles and 5 percent cobbles; neutral (pH 6.8); clear smooth boundary. (2 to 6 inches thick)
A2--2 to 9 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; 5 percent pebbles and 5 percent cobbles; neutral (pH 7.0); clear smooth boundary. (2 to 8 inches thick)
Bw1--9 to 13 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few very fine roots; many very fine tubular pores; 5 percent pebbles and 5 percent cobbles; neutral (pH 7.2); abrupt smooth boundary. (3 to 6 inches thick)
Bw2--13 to 16 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few very fine roots; few very fine tubular pores; 5 percent pebbles and 5 percent cobbles; neutral (pH 7.2); abrupt irregular boundary. (3 to 8 inches thick)
2Crk--16 to 21 inches; light yellowish brown (10YR 6/4) sandstone, brown (10YR 4/3) moist; very hard and extremely firm; can be chipped with a spade with difficulty; thin lime coating on surface. (4 to 8 inches thick)
2R--21 inches; sandstone
TYPE LOCATION: Jefferson County, Oregon; 300 feet east of the road and 300 feet south of road in the SE1/4 SW1/4 SW1/4 section 5, T. 13 S., R. 14 E.
RANGE IN CHARACTERISTICS: McCoin soils are dry throughout for one-half to three-fourths of the time (cumulative) that the soil temperature is about 41 degrees F., and are dry for 90 to 120 days. The mean annual soil temperature is 48 to 52 degrees F. Depth to paralithic bedrock ranges from 12 to 20 inches and to lithic bedrock below 20 inches. The solum contains from 5 to 10 percent pebbles and 5 to 10 percent cobbles. The solum may contain up to 50 percent paragravel fragments.
The A horizon has value of 4 or 5 dry.
The Bw horizon has value of 5 or 6 dry and 3 or 4 moist, and chroma of 3 or 4. It is clay loam or loam with 22 to 30 percent clay, and has weak or moderate subangular blocky structure.
COMPETING SERIES: This is the Tincan series. Tincan soils lack a cambic horizon.
GEOGRAPHIC SETTING: The McCoin soils are on undulating to rolling hills at elevations of 1,300 to 3,800 feet. Slope gradients range from 2 to 60 percent. These soils formed in medium to moderately fine textured colluvium over semiconsolidated sediments. The climate is semiarid with hot summers and cold winters; mean annual temperature is 46 to 52 degrees F., mean winter temperature is 32 to 33 degrees F., mean summer temperature is 62 to 64 degrees F., and mean annual precipitation is 9 to 12 inches. The frost-free period is 70 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Court, Era, Lamonta and Madras soils. All of these soils are deeper than 20 inches. Court soils are on alluvial fans and have contrasting textures within the control section. Era soils have calcareous horizons. Lamonta and Madras soils have argillic horizons and duripans.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Range and cropland. Large areas of cropland have been seeded to perennial grasses. Native vegetation is bluebunch wheatgrass, Idaho fescue, bitterbrush, and associated forbs.
DISTRIBUTION AND EXTENT: Central Oregon; MLRA 10, John Day area. Series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Jefferson County (Trout Creek-Shaniko Area), Oregon, 1970.
REMARKS: Diagnostic horizons and other features:
Mollic epipedon - from 0 to 9 inches
Cambic Horizon - from 9 to 16 inches
Paralithic contact - from 16 to 21 inches
Lithic contact - at 21 inches