LOCATION LEONARDO WAEstablished Series
TAXONOMIC CLASS: Ashy over loamy-skeletal, glassy over isotic Humic Xeric Vitricryands
TYPICAL PEDON: Leonardo ashy fine sandy loam, grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 8 inches; dark grayish brown (10YR 4/2) channerery ashy fine sandy loam, black (10YR 2/1) moist; moderate medium granular structure; soft, friable, nonsticky and nonplastic; many fine roots; beginning of turf mat; 15 percent shale fragments; moderately acid (pH 6.0); clear wavy boundary. (7 to 9 inches thick)
A2--8 to 16 inches; dark grayish brown (10YR 4/2) ashy fine sandy loam, very dark brown (10YR 2/2) moist; weak fine granular structure; soft, friable, nonsticky and nonplastic; many fine roots; 10 percent shale fragments moderately acid (pH 6.0); clear wavy boundary. (8 to 10 inches thick)
AC--16 to 38 inches; brown (10YR 4/3) stony ashy fine sandy loam, dark brown (10YR 3/3) moist; single grained; loose, friable, nonsticky and nonplastic; few fine roots; 10 percent shale fragments, and 15 percent angular stones; moderately acid (pH 6.0); clear wavy boundary. (10 to 24 inches thick)
2C--38 to 60 inches; yellowish brown (10YR 5/4) extremely stony sandy loam, brown (10YR 4/3) moist; single grained; loose, friable, nonsticky and nonplastic; 50 percent angular stone, 20 percent shale fragments; moderately acid (pH 5.8).
TYPE LOCATION: Ferry County, Washington; on Taylor Ridge, Kettle Falls Ranger District, Colville National Forest; NW1/4 sec. 15, T.38N., R.35E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at depth of 20 inches ranges from 38 degrees to 42 degrees F. and mean summer temperature is 43 degrees to 47 degrees F. The upper part of the control section contains more than 30 percent pyroclastic glass in the sand and coarse silt materials. These soils are usually moist but are dry in all parts between 8 and 24 inches for 60 to 75 consecutive days following summer solstice. Content of coarse fragments in the upper portion of the particle-size control section ranges from 5 to 35 percent. Content of coarse fragments in the lower portion of the control section exceeds 50 percent. The mollic epipedon has a base saturation of 55 to 70 percent, and is more than 20 inches thick. The solum is 25 to 40 inches thick. The soils are moderately to slightly acid.
The A horizon has value of 3 or 4 dry, and chroma of 1 or 2 dry or moist. It is ashy fine sandy loam or ashy loam and is gravelly in some pedons. This horizon has weak to moderate granular structure.
The AC horizon has value of 4 or 5 dry, and chroma of 2 or 3 moist or dry. It is ashy loam or ashy fine sandy loam and is gravelly or stony.
The 2C horizon has value of 5 or 6 dry and chroma of 3 or 4 dry. It is sandy loam or fine sandy loam and is very gravelly, extremely stony, very gravelly or very stony.
COMPETING SERIES: These are the Toroda soils and the similar Buckhouse, Growden, and Maude series. Toroda soils are neutral or slightly acid, have a cambic horizon. Buckhouse soils are strongly to very strongly acid. Growden soils have umbric epipedons. Maude soils are massive in all parts, contain pumice within the control section and have umbric epipedons.
GEOGRAPHIC SETTING: Leonardo soils are on moderately steep to very steep glaciated mountain slopes at elevations of 5,500 to 6,500 feet. They formed in volcanic ash, loess, and material from siliceous rocks. These soils occur in a cold subhumid climate; mean annual temperature is about 40 degrees F.; and frost-free season is about 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Growden soils and the Edds, Scar, and Togo soils. Edds soils have a portion of the control section not dominated by volcanic ash. Scar soils lack 60 percent volcanic ash. Togo soils lack mollic epipedons.
DRAINAGE AND PERMEABILITY: Well-drained; medium to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Grazed woodland, Douglas-fir, ponderosa pine, Idaho fescue, rough fescue, bluebunch wheatgrass, and Wyeth buckwheat.
DISTRIBUTION AND EXTENT: Northeastern Washington. Series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Ferry County, Washington, 1971.
REMARKS: Diagnostic horizons and feature recognized in this pedon are:
Mollic epipedon, the zone from 0 to 38 inches; (A1, A2, and AC horizons)
The upper 38 inches of the soil is more than 30 percent volcanic glass (A and AC horizons). This draft reflects a change in classification from Medial over loamy-skeletal, mixed, Typic Cryandepts to Ashy over loamy-skeletal, glassy over isotic Humic Xeric Vitricryands