LOCATION ZER IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Xeric Haplocalcids
TYPICAL PEDON: Zer gravelly loam - on a 5 percent northeast facing slope at an elevation of 5,800 feet in rangeland. (Colors are for dry soil unless otherwise noted. When described on October 19, 1981, the soil was moist to 8 inches.)
A--0 to 2 inches; grayish brown (10YR 5/2) gravelly loam, dark grayish brown (10YR 4/2) moist; moderate thick platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; common fine tubular pores; slightly effervescent; 15 percent gravel; slightly alkaline (pH 7.8); clear smooth boundary. (2 to 6 inches thick)
Bw--2 to 9 inches; pale brown (10YR 6/3) gravelly silt loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; common fine tubular pores; strongly effervescent (about 9 percent calcium carbonate); 10 percent gravel; 5 percent cobbles; moderately alkaline (pH 8.0); clear smooth boundary. (0 to 7 inches thick)
Bkq1--9 to 13 inches; very pale brown (10YR 7/3) gravelly sandy loam, brown (10YR 5/3) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; common fine tubular pores; violently effervescent (about 30 percent calcium carbonate equivalent); 20 percent gravel; bottom sides of gravel have lime and silica pendants; moderately alkaline (pH 8.4); clear smooth boundary. (4 to 6 inches thick)
Bkq2--13 to 20 inches; very pale brown (10YR 7/3) very gravelly sandy loam, pale brown (10YR 6/3) moist; strong fine and medium subangular blocky structure; hard, friable, nonsticky and slightly plastic; common very fine and fine roots; few tubular pores; violently effervescent (about 40 percent calcium carbonate equivalent); 30 percent gravel, 5 percent cobbles; undersides of fragments have lime and silica pendants; strongly alkaline (pH 8.6); clear smooth boundary. (7 to 13 inches thick)
Bk1--20 to 32 inches; very pale brown (10YR 8/2) extremely gravelly sandy loam, light yellowish brown (10YR 6/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine and fine roots; few tubular pores; violently effervescent (about 40 percent calcium carbonate equivalent); 50 percent gravel, 10 percent cobbles; strongly alkaline (pH 8.6); gradual smooth boundary. (12 to 14 inches thick)
Bk2--32 to 41 inches; very pale brown (10YR 7/4) extremely gravelly loamy sand, yellowish brown (10YR 5/4) moist; single grain; loose; common very fine and fine roots; few tubular pores; violently effervescent (about 30 percent calcium carbonate equivalent); 60 percent gravel, 5 percent cobbles; strongly alkaline (pH 8.6); gradual smooth boundary. (9 to 15 inches thick)
Bk3--41 to 60 inches; light yellowish brown (10YR 6/4) very gravelly loamy sand, yellowish brown (10YR 5/4) moist; single grain; loose; few very fine and fine roots; violently effervescent (about 18 percent calcium carbonate equivalent); 40 percent gravel, 5 percent cobbles; strongly alkaline (pH 8.6).
TYPE LOCATION: Clark County, Idaho, about 17 miles west and 1 mile north of Dubois; 2,250 feet north and 1,050 feet west from the southeast corner of section 16, T. 10 N., R. 33 E.
RANGE IN CHARACTERISTICS:
Particle-size control section - weighted average 10 to 18 percent total clay Rock fragments in particle-size control section - 35 to 80 percent Depth to carbonates - 0 to 7 inches Depth to the calcic horizon (Bkq) - 5 to 10 inches Calcic horizon contains 15 to 40 percent calcium carbonate equivalent Average annual soil temperature - 41 to 45 degrees F. Average summer soil temperature - 59 to 63 degrees F. The soil moisture control section is dry for one-half to three-fourths of the time with the soil temperature is above 41 degrees F; aridic bordering on xeric.
A horizon
Value - 5 or 6 dry, 2 through 5 moist
Chroma - 2 through 4 dry or moist
Reaction slightly to very strongly alkaline
Bw, Bkq and Bk1 horizons
Hue - 7.5YR or 10YR
Value - 5 through 8 dry, 3 through 6 moist
Chroma - 2 to 4 dry or moist
Texture - gravelly through extremely gravelly loam, silt loam, or sandy loam Gravel - 15 to 40 percent
Cobbles - 0 to 20 percent
Stones - 0 to 20 percent
Reaction - slightly to strongly alkaline
Bk2 and Bk3 horizons
Value - 6 through 8 dry, 3 through 7 moist
Chroma - 2 through 4 dry or moist
Texture - gravelly through extremely gravelly loam, sandy loam, fine sandy loam, loamy sand or sand
Gravel - 20 to 60 percent
Cobbles - 5 to 10 percent
Stones - 0 to 20 percent
Reaction - moderately to strongly alkaline
COMPETING SERIES: These are the Holinrock, Misfire, and Packmo series. Packmo soils have depth to carbonates 10 to 13 inches. Holinrock soils are moderately deep. Misfire soils have a calcic horizon at depths of 11 to 17 inches.
GEOGRAPHIC SETTING: Zer soils are on mountains, foothills, outwash fans and terraces and have slopes of 0 to 50 percent. Elevations are 4,000 to 8,000 feet. The soils formed in slope alluvium and colluvium from mixed sources. The climate is cold and moist in winter and dry in summer. The average annual precipitation ranges from 6 to 13 inches. The average summer temperature is 62 to 66 degrees F. and the average annual temperature is 37 to 44 degrees F. The frost-free period is 45 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Mogg series. Mogg soils have bedrock at 10 to 20 inches.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately rapid or moderate permeability.
USE AND VEGETATION: These soils are used for range. Vegetation is dominantly low sagebrush, threetip sagebrush, rabbitbrush, bluebunch wheatgrass, and Indian ricegrass.
DISTRIBUTION AND EXTENT: These soils are extensive in southeastern Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Custer-Lemhi Counties, Idaho, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Calcic horizon - the zone from 9 to 41 inches (Bkq1, Bkq2, Bk1, and Bk2 horizons)
Cambic horizon - from 2 to 9 inches (this horizon is absent in many pedons)
Particle-size control section - the zone from 10 to 40 inches (part of the Bkq1, the Bkq2, Bk1, and part of the Bk2 horizons)