LOCATION ZAZA IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Lithic Haploxerepts
TYPICAL PEDON: Zaza loam - on an 18 percent slope, south-southwest aspect, 4,840 feet elevation, in forest. When described on June 11, 1976 the profile was moist. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inch; undecomposed and partially decomposed needles, leaves, and twigs; moderately acid (pH 5.6).
A--1 to 4 inches; brown (7.5YR 5/4) loam, dark reddish brown (5YR 3/4) moist; moderate fine and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine roots; many fine irregular pores; 10 percent fine gravel; moderately acid (pH 5.8); abrupt smooth boundary. (2 to 5 inches thick)
BA--4 to 8 inches; brown (7.5YR 5/4) very gravelly loam, dark reddish brown (5YR 3/4) moist; moderate very fine and fine subangular blocky and moderate very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and common coarse roots; many fine tubular pores; 35 percent gravel; moderately acid (pH 5.8); clear wavy boundary. (2 to 5 inches thick)
Bw--8 to 13 inches; reddish brown (5YR 5/4) very gravelly loam, dark reddish brown (5YR 3/4) moist; moderate very fine and fine subangular blocky and moderate very fine and fine granular structure; slightly hard, friable, sticky and plastic; many fine and common coarse roots; many fine tubular pores; about 50 percent gravel; moderately acid (pH 5.8); abrupt wavy boundary. (4 to 10 inches thick)
R--13 inches; fractured basalt with soil material in cracks.
TYPE LOCATION: Idaho County, Idaho; about 8 miles southwest of Grangeville; about 2,300 feet south and 1,300 feet west of the northeast corner of section 27, T. 29 N., R. 2 E. Latitude - 45 degrees, 49 minutes, 27 seconds North; Longitude - 116 degrees, 11 minutes, 08 seconds West; USGS White Bird Hill Quadrangle.
RANGE IN CHARACTERISTICS:
Depth to bedrock - 10 to 20 inches
Average annual soil temperature - 43 to 47 degrees F.
Particle-size control section
Rock fragments - 35 to 85 percent
A horizon
Hue - 7.5YR or 5YR
Value - 4 through 6 dry, 3 or 4 moist
Chroma - 2 through 4, dry or moist
Reaction - moderately acid or slightly acid
Bw horizon
Hue - 7.5YR or 5YR
Value - 4 through 6 dry, 3 or 4 moist
Texture - CBX-L, CBV-L, GRX-L
Reaction - moderately acid or slightly acid
Base saturation - (by NH4OAc) greater than 60 percent
COMPETING SERIES: This is the Sherod series and the similar Riggins series. The Sherod soils have a water table between 12 and 18 inches at sometime in most years and meet vitrandic subgroup criteria. The Riggins soil in a closely related family has an argillic horizon and a mollic epipedon.
GEOGRAPHIC SETTING: Zaza soils are on south-facing canyon and mountain slopes and hills on plateaus and have slopes of 4 to 65 percent. They formed in residuum and colluvium from basalt with loess mixed into the upper layers. Elevations are 4,000 to 5,350 feet. The average annual precipitation is 26 to 28 inches. The climate is humid with cold, snowy winters and moderately warm, dry summers. The average annual temperature is 42 to 46 degrees F., and the frost season is 60 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brody, Cramont, Culdesac, Klickson and Wapshilla soils. Brody and Culdesac soils have volcanic ash in the surface layers and are on north and east aspects. Cramont soils have fine textured argillic horizons, are very deep, and are on broad ridges. Klickson soils are deep and are on similar landscape positions. Wapshilla soils have argillic horizons, are very deep, and are on north and east aspects.
DRAINAGE AND PERMEABILITY: Well drained; rapid and very rapid runoff; moderate permeability.
USE AND VEGETATION: Zaza soils are used mostly for woodland and woodland grazing. The natural vegetation is mainly Douglas-fir, ponderosa pine, lodgepole pine, baldhip rose, common snowberry, bluebunch wheatgrass, and silky lupine.
DISTRIBUTION AND EXTENT: Northern Idaho. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Idaho County, Idaho, 1976.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 4 inches (Oi and A horizons).
Cambic horizon - the zone from 4 to 13 inches (BA and Bw horizons)
Lithic contact - the top of the R horizon.
Particle-size control section - the zone from 1 to 13 inches (A, BA, and the Bw horizon)