LOCATION GACIBA                  ID

Established Series
Rev. RWW/KWH/HBM
11/2010

GACIBA SERIES

The Gaciba series consists of shallow to bedrock, well drained soils formed in residuum and slope alluvium derived dominantly from extrusive igneous rock. Gaciba soils are on mountains, lava plains, and foothills. Permeability is moderate. Slopes are 0 to 60 percent. The average annual precipitation is about 12 inches, and the average annual air temperature is about 39 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Aridic Lithic Argixerolls

TYPICAL PEDON: Gaciba gravelly loam on a 25 percent east-facing slope at an elevation of 5,500 feet on rangeland. (Colors are for dry soil unless otherwise noted. When described on November 6, 1979, the soil was dry throughout.)

A--0 to 4 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine interstitial pores; 30 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (3 to 6 inches thick)

Bt1--4 to 10 inches; brown (10YR 5/3) very gravelly loam, dark brown (10YR 3/3) moist; weak very fine and fine subangular blocky structure; slightly hard, very friable, slightly sticky, and slightly plastic; many very fine and fine roots; many very fine tubular pores; common faint clay film on faces of peds and in pores; 35 percent gravel; neutral (pH 7.2); clear wavy boundary. (2 to 8 inches thick)

Bt2--10 to 15 inches; yellowish brown (10YR 5/4) very gravelly loam, brown (10YR 4/3) moist; weak very fine and fine subangular blocky structure; slightly hard, very friable, slightly sticky, and slightly plastic; many very fine and fine roots; many very fine tubular pores, common faint and few distinct clay films on faces of peds and in pores; 40 percent gravel; slightly alkaline (pH 7.4); abrupt smooth boundary. (3 to 7 inches thick)

R--15 inches; basalt

TYPE LOCATION: Custer County, Idaho; about 6 miles northwest of Challis, Idaho; about 400 feet east and 350 feet south of the northwest corner, sec. 6, T. 14 N., R. 18 E. Latitude - 44 degrees, 34 minutes, 42 seconds North; Longitude - 114 degrees, 17 minutes, 30 seconds West.

RANGE IN CHARACTERISTICS:

Profile:
Average annual soil temperature - 39 to 46 degrees F
Thickness of the mollic - 8 to 13 inches
Depth to bedrock - 12 to 20 inches
Reaction of profile - neutral or slightly alkaline

Particle-size control section:
Clay content averages - 16 to 24 percent
Rock fragments content- 35 to 60 percent

A horizon :
Value - 4 or 5 dry
Chroma - 2 through 4 dry or moist

Bt horizon:
Value - 4 or 5 dry and 3 or 4 moist
Chroma - 2 through 4 dry or moist
Coarse fragments average - 35 to 60 percent

Bk horizon (when present):
Value - 4 or 5 dry and 3 or 4 moist
Chroma - 2 through 4 dry or moist
Coarse fragments - 35 to 60 percent

COMPETING SERIES: These are the Anaud(T), Bellenmine(T), Cleavage, Cropper(T), Gabica, Hutchley, Mascamp, Pernty, Poisoncreek(T), Shalcleav(T), Shalper(T), and Tweener(T) series. Anaud soils have 25 to 34 percent clay in the control section and 30 to 38 percent clay in the Bt horizon. Bellenmine soils have a paralithic contact at 6 to 14 inches in depth above the lithic contact. Cleavage soils do not have mollic epipedons that extend into the upper part of the argillic horizon. Cropper soils have 27 to 35 percent clay in the control section. Gabica soils have 18 to 25 inches of annual precipitation, A xeric moisture regime, and are dry for 45 to 70 consecutive days. Hutchley soils have 24 to 35 percent clay in the control section. Mascamp soils have sandy clay loam textures in the argillic horizons and 60 to 80 percent rock fragments in the control section. Pernty and Poisoncreek soils have 25 to 35 percent clay in the Bt horizon. Shalcleav soils have 28 to 35 percent clay in the control section and have hard bedrock at 4 to 12 inches. Shalper soils are 4 to 12 inches to bedrock and have 24 to 35 percent clay in the control section. Tweener soils are 7 to 12 inches to bedrock and have mainly cobbles and stones as rock fragments in the control section.

GEOGRAPHIC SETTING: Gaciba soils are on mountains, foothills, and lava plains and have slopes of 0 to 60 percent. Elevations are 5,000 to 7,500 feet. The soils formed in residuum, lava plains, and slope alluvium from extrusive igneous rock. The climate is cold and moist in winter and spring and dry in summer. Average annual precipitation is 11 to 14 inches. Average summer air temperature is 60 to 66 degrees F. Average annual air temperature is 37 to 44 degrees F. Frost-free period is 45 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Custco, Dacont, Dawtonia, Nielsen, Resoot, and Zeebar soils on mountains and foothills. Custco, Dacont, Dawtonia, Resoot, and Zeebar soils are on mountains and are very deep. Nielsen soils are on mountain ridges and have a cryic temperature regime.

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

USE AND VEGETATION: The soils are dominantly used for range. Vegetation is mainly Wyoming big sagebrush and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: East-central Idaho. These soils are not extensive.

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

SERIES ESTABLISHED: Custer County, Idaho, 1999.

REMARKS: Diagnostic horizons and features in this pedon are:

Mollic epipedon - The zone from the surface to a depth of 10 inches (A and Bt horizons).

Argillic horizon - The zone from 4 to 15 inches (Bt1 and Bt2 horizons).

Bedrock - At a depth of 15 inches.

Particle-size control section - The zone from 4 to 15 inches (Bt horizons).

Moisture Regime - Aridic

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National Cooperative Soil Survey
U.S.A.