LOCATION HOLINROCK          ID
Established Series
Rev. KWH/CLM/HBM
09/1999

HOLINROCK SERIES


The Holinrock series consists of moderately deep, well drained soils that formed of residuum and colluvium from extrusive igneous rocks. The Holinrock soils are on ridges and foothills. Permeability is moderate. Slopes are 15 to 40 percent. The average annual precipitation is about 8 inches and average annual temperature is about 39 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Xeric Haplocalcids

TYPICAL PEDON: Holinrock gravelly loam--on a 35 percent west-facing slope in rangeland at 5,900 feet elevation. (Colors are for dry soil unless otherwise noted. When described on July 16,1984, the soil was dry throughout.)

A--0 to 2 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure parting to weak fine granular; soft, very friable, slightly sticky and slightly plastic; many very fine and fine and few medium roots; many very fine and fine irregular pores; 30 percent gravel; lime coatings less than 1 mm thick on coarse fragments; slightly alkaline (pH 7.5); clear wavy boundary. (1 to 3 inches thick)

Bw--2 to 6 inches; yellowish brown (10YR 5/4) very gravelly loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine and few medium roots; common very fine and fine irregular pores; 35 percent gravel; slightly alkaline (pH 7.5); gradual wavy boundary. (0 to 4 inches thick)

Bkq1--6 to 13 inches; pale brown (10YR 6/3) very gravelly loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, fine and medium roots; many fine irregular pores; 35 percent gravel; lime and silica coatings less than 1 mm thick on undersides of coarse fragments; few soft masses of secondary lime; strongly effervescent; moderately alkaline (pH 8.0) clear wavy boundary. (4 to 8 inches thick)

Bkq2--13 to 24 inches; pale brown (10YR 6/3) very gravelly loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine and fine irregular pores; 45 percent gravel; fine gravel are coated with lime and silica; few root mats between peds; moderately alkaline (pH 8.2); clear wavy boundary. (8 to 11 inches thick)

Bkq3--24 to 29 inches; yellowish brown (10YR 5/4) extremely gravelly loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine and fine irregular pores; 50 percent gravel 15 percent cobbles; many root mats on sides of coarse fragments; lime and silica coatings 2 to 8 mm thick on sides and undersides of coarse fragments; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (2 to 9 inches thick)

R--29 inches; fractured rhyodacite; lime and silica coatings 5 millimeter to 1 centimeter thick in fractures which are greater than 4 inches apart.

TYPE LOCATION: Custer County, Idaho; about 8.5 miles southeast of Challis, Idaho; about 1,800 feet south and about 1,350 feet west from the northeast corner of section 28, T. 13 N., R. 20 E. Latitude - 44 degrees, 25 minutes, 48 seconds North; Longitude - 114 degrees, 05 minutes, 52 seconds West.

RANGE IN CHARACTERISTICS:

Average annual soil temperature - 40 to 43 degrees F.
Control section - Percent clay: 18 to 26
Coarse fragments: 35 to 65
Depth to calcic horizon - 3 to 7 inches
Depth to bedrock - 21 to 35 inches

A horizon
Value - 5 or 6 dry, 3 or 4 moist

Bkq horizon
Value - 5 through 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Coarse fragments - 35 to 65 percent
Texture - GRV-L, GRX-L
Reaction - slightly or moderately alkaline

COMPETING SERIES: These are the Misfire, Packmo, and Zer soils. Misfire, Packmo and Zer soils are very deep.

GEOGRAPHIC SETTING: Holinrock soils are on ridges and foothills. They formed in colluvium and residuum from extrusive igneous rock. Slopes are 15 to 40 percent and elevations are 5,300 to 6,500 feet. The climate is cold and moist in winter and dry in summer. Average annual precipitation is 7 to 10 inches; average annual temperature is 38 to 41 degrees F. and the frost free period is 60 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Farvant, Mitring, Sprabat and Snowslide soils. Farvant soils, on mountains and ridges are shallow to a paralithic contact. Snowslide and Sprabat soils are on fan terraces and are very deep. Mitring soils are on ridge sideslopes and are moderately deep to a paralithic contact.

DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.

USE AND VEGETATION: Rangeland. Vegetation is shadscale, bluebunch wheatgrass, needleandthread and winterfat.

DISTRIBUTION AND EXTENT: East-central Idaho. This soil is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Custer County, Idaho, 1999.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - the zone from 0 to 6 inches (A and Bw horizons)

Calcic horizon - the zone from 6 to 29 inches (Bkq horizon)

Lithic contact - the boundary is at 29 inches (R horizon)

Particle-size control section - the zone from 10 inches to the lithic contact (part of Bkq1, the Bkq2 and the Bkq3 horizons)


National Cooperative Soil Survey
U.S.A.