LOCATION MIRES WA+MTEstablished Series
TAXONOMIC CLASS: Ashy over sandy or sandy-skeletal, glassy over mixed, frigid Humic Vitrixerands
TYPICAL PEDON: Mires ashy loam, cropland. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 6 inches; dark gray (10YR 4/1) ashy loam, black (10YR 2/1) moist; weak fine granular structure; soft, very friable, slightly plastic; many roots; 10 percent gravel; neutral (pH 6.6); abrupt smooth boundary. (6 to 8 inches thick)
A--6 to 14 inches; dark grayish brown (10YR 4/2) ashy loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; soft, very friable, slightly plastic; many roots; many very fine pores; 10 percent gravel; neutral (pH 6.7); abrupt wavy boundary. (4 to 11 inches thick)
Bw--14 to 21 inches; yellowish brown (10YR 5/4) very gravelly ashy sandy loam, dark yellowish brown (10YR 3/4) moist; weak medium subangular blocky structure; soft, very friable; common roots; many fine and very fine pores; 45 percent gravel; neutral (pH 6.9); clear wavy boundary. (7 to 10 inches thick)
C1--21 to 26 inches; pale brown (10YR 6/3) very gravelly loamy sand, brown (10YR 4/3) moist; massive; loose; common roots; 50 percent gravel and cobblestones; neutral (pH 6.9); abrupt wavy boundary. (4 to 6 inches thick)
2C2--26 to 48 inches; very gravelly coarse sand; loose; 50 percent gravel and cobblestones; neutral (pH 7.0); lime coatings on underside of some coarse fragments. (Many feet thick)
TYPE LOCATION: Ferry County, Washington; 390 feet south and 180 feet east of the NW corner in NW1/4 NW1/4 section 16, T.37N., R.33E.
RANGE IN CHARACTERISTICS: Solum thickness is 17 to 19 inches. The mean annual soil temperature is 44 to 47 degrees F. The upper part of the control section averages 30 to 60 percent pyroclastic glass. Coarse fragments in the soil average from 10 to 35 percent by volume, and range up to 50 percent in some subhorizons. Thickness of the mollic epipedon is 10 to 19 inches. The pH values range from 6.4 to 7.2.
The A horizon has value of 3 or 4 dry and chroma of 1 or 2. It is ashy silt loam or ashy sandy loam, and may be gravelly, cobbly or stony.
The Bw horizon has value of 4 through 6 dry, 3 or 4 moist, and chroma of 3 or 4. It is typically a gravelly ashy sandy loam, but the range includes cobbly ashy sandy loam.
The 2C horizon has value of 5 or 6 dry, 3 or 4 moist, and chroma of 3 or 4. It ranges from very gravelly loamy sand to very gravelly sand and very cobbly sand.
COMPETING SERIES: This is the Goosmus series. Goosmus soils have chroma of 3 in the lower part of the mollic epipedon.
GEOGRAPHIC SETTING: Mires soils are on level to sloping glacial outwash terraces at elevations of 1,800 to 3,500 feet. They formed in a mantle of loess and volcanic ash over glacial outwash of mixed mineralogy. These are in a continental climate. The mean annual precipitation is 14 to 18 inches; the mean annual temperature is 43 degrees F.; and the frost free season is 95 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chesaw, Hunters, Molson, Phoebe, and Republic soils. Chesaw soils are sandy-skeletal. Hunters soils are fine-silty. Molson soils are ashy over loamy. Phoebe and Republic soils are coarse-loamy.
DRAINAGE AND PERMEABILITY: Well drained; permeability is moderate; runoff is slow to medium.
USE AND VEGETATION: Irrigated grass and legume hay, pasture, small grains, and range. The native vegetation is bluebunch wheatgrass, Idaho and rough fescue, Sandberg bluegrass, needlegrass, and scattered ponderosa pine and Douglas-fir.
DISTRIBUTION AND EXTENT: North, central Washington, east to Upper Flathead Valley of Montana. These are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Flathead County (Upper Flathead Valley Area), Montana, 1958.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the soil surface to 14 inches (Ap and A horizons)
Cambic horizon - the zone from 14 inch to 21 inches (Bw horizon)
Strongly contrasting particle-size classes at 21 inches.
Particle-size control section - the zone from 0 to 40 inches (the Ap, A, Bw, 2C1, and part of the 2C2.
The 10/2001 draft reflects a change in classification from Ashy over sandy or sandy-skeletal, mixed, frigid Mollic Vitrandepts to Ashy over sandy or sandy-skeletal, glassy over mixed, frigid Humic Vitrixerands. This change is based on Soil Taxonomy 2nd Edition