LOCATION ZEPH IDEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, frigid Aeric Fluvaquents
TYPICAL PEDON: Zeph silty clay -- on a 1 percent slope at 4880 feet elevation in pasture. (Colors are for dry soil unless otherwise noted. When described on October 17, 1991, the soil was moist from the surface to 24 inches and a water table was present at 24 inches).
Oe--0 to 3 inches; moderately decomposed roots. (0 to 3 inches thick)
Ag--3 to 8 inches; gray (N 5/0) silty clay, very dark grayish brown (2.5Y 3/2) moist; moderate medium angular blocky structure; hard, firm, very sticky and very plastic; many very fine and fine roots; many fine and very fine tubular pores; slightly effervescent; slightly alkaline (pH 7.7); abrupt smooth boundary. (4 to 9 inches thick)
2Cg1--8 to 19 inches; gray (N 6/0) very gravelly coarse sand, dark olive gray (5Y 3/2) moist; single grain; loose; many very fine and fine roots; many very fine and fine irregular pores; 45 percent gravel; slightly alkaline (pH 7.8); abrupt smooth boundary. (8 to 11 inches thick)
2Cg2--19 to 22 inches; yellowish red (5YR 5/8) extremely gravelly coarse sand, dark brown (7.5YR 3/4) moist; single grain; loose; common very fine and fine roots; many very fine and fine irregular pores; 60 percent gravel; slightly alkaline (pH 7.4); abrupt smooth boundary. (0 to 19 inches thick)
2Cg3--22 to 26 inches; gray (5Y 6/1) extremely gravelly coarse sand, olive gray (5Y 4/2) moist; many medium prominent strong brown (7.5YR 5/6) redox concentrations on coarse fragments; single grain; loose; common very fine and fine roots; many very fine and fine irregular pores; 60 percent gravel; slightly alkaline (pH 7.5); clear smooth boundary. (4 to 22 inches thick)
2Cg4--26 to 63 inches; multicolored extremely gravelly coarse sand; many fine prominent strong brown (7.5YR 5/6) redox concentrations on coarse fragments; single grain; loose; few very fine and fine roots; many fine irregular pores; 40 percent gravel, 15 percent cobbles, 5 percent stones; neutral (pH 7.3).
TYPE LOCATION: Lemhi County, Idaho; about 16 miles southeast of Salmon, Idaho, about 1,300 feet north and 250 feet west of the southeast corner of section 6, T.19N. R.24E. Latitude - 45 degrees, 00 minutes, 8 seconds, North; Longitude - 115 degrees, 39 minutes, 38 seconds, West.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 40 to 42 degrees
Control section - Percent clay - 5 to 8 percent; rock fragments average over 50 percent
Depth to sand and gravel - 4 to 9 inches
Depth to water table - 6 to 18 inches in March through June
Reaction of profile - neutral through slightly alkaline
Ag horizon
Hue - N, 2.5Y, 10YR
Value - 2 through 5 dry, 2 or 3 moist
Chroma - 0 through 2 dry, 1 or 2 moist
2Cg1 horizon
Hue - N, 2.5Y, 5Y
Value - 4 through 6 dry, 3 or 4 moist
Chroma - 0 through 2 dry, 2 or 3 moist
Texture - GRX-COS, GRX-LCOS, GRV-COS,
Coarse fragments - 45 to 70 percent
2Cg2 horizon (absent in some pedons)
Hue - 5YR, 7.5YR
Value - 5 or 6 dry, 3 through 5 moist
Chroma - 6 through 8 dry, 4 through 6 moist
Texture - GRX-COS, GRX-LCOS, GRV-COS
Coarse fragments - 45 to 70 percent
2Cg3 and 2Cg4 horizons
Value - 5 through 7 dry, 3 through 5 moist
Chroma - 1 through 3 dry, 2 through 4 moist
Texture - GRX-COS, GRX-LCOS
Rock fragments - 60 to 80 percent
COMPETING SERIES: This is the Canarway series. Canarway soils typically will average less than 50 percent rock fragments in the particle-size control section.
GEOGRAPHIC SETTING: Zeph series are on flood plains. These soils formed in mixed riverine alluvium. Slopes are 0 to 2 percent. Elevations are 4,200 to 5,200 feet. The climate is cold and moist in winter and spring, and dry in summer. Average annual precipitation is 9 to 12 inches. Average annual temperature is 42 to 44 degrees F. The frost-free period is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ajax and Wimpey soils. Ajax soils are in depressions on flood plains and have fine textured particle-size control sections and mollic epipedons. Wimpey soils are on smooth positions on flood plains and have contrasting particle-size control sections and mollic epipedons that are greater than 20 inches thick. Ajax soils are in depressions on flood plains and Wimpey soils are on smooth positions on flood plains.
DRAINAGE AND PERMEABILITY: Poorly drained. Slow runoff. Permeability is slow over very rapid. This soil floods occasionally for brief periods in January through June.
USE AND VEGETATION: Used mostly for flood irrigated grass hay and pasture. The principle native vegetation is sedges, western wheatgrass and willows.
DISTRIBUTION AND EXTENT: East-central Idaho. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lemhi County, Idaho, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Particle-size control section - the zone from 13 to 43 inches (part of the 2Cg1 horizon, the 2Cg2 horizon, 2Cg3 horizon and part of the 2Cg4 horizon)
All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.