LOCATION MENAN IDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Xeric Calciargids
TYPICAL PEDON: Menan silt loam, rangeland; on a 1 percent slope at 5,310 feet elevation under basin big sagebrush and basin wild rye. When described on June 24, 1993, the soil was dry throughout. (Color is for dry soil unless otherwise noted.)
A1--0 to 3 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; few very fine tubular pores; 2 percent basalt gravel; slightly alkaline (pH 7.4); clear smooth boundary. (1 to 4 inches thick)
A2--3 to 7 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; few very fine tubular pores; 1 percent basalt gravel; slightly alkaline (pH 7.6); clear smooth boundary. (3 to 7 inches thick)
Bt1--7 to 13 inches; pale brown (10YR 6/3) silty clay loam, brown (10YR 4/3) moist; weak and moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; few faint clay films on faces of peds; 1 percent basalt gravel; slightly alkaline (pH 7.7); clear smooth boundary. (3 to 6 inches thick)
Bt2--13 to 27 inches; pale brown (10YR 6/3) silty clay loam, dark brown (10YR 3/3) moist; moderate fine prismatic structure parting to strong fine subangular blocky; hard, friable, moderately sticky and moderately plastic; common very fine, fine and medium roots; common very fine and fine tubular and irregular pores; common faint clay films on faces of peds; 1 percent basalt gravel; slightly alkaline (pH 7.8); gradual wavy boundary. (9 to 14 inches thick)
Bt3--27 to 33 inches; pale brown (10YR 6/3) silty clay loam, brown (10YR 4/3) moist; strong medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; common very fine and fine tubular and irregular pores; common faint clay films on faces of peds; 1 percent basalt gravel; moderately alkaline (pH 7.9); clear smooth boundary. (6 to 7 inches thick)
Btk--33 to 38 inches; pale brown (10YR 6/3) silty clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; common very fine tubular pores; common hard coarse rounded nodules or cicada krotovinas; 1 percent basalt gravel; slightly effervescent (12 percent calcium carbonate equivalent); moderately alkaline (pH 8.0); clear wavy boundary. (0 to 12 inches thick)
Bk1--38 to 51 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine, fine, and medium roots; common very fine tubular pores; many hard coarse rounded nodules or cicada krotovinas; strongly effervescent (20 percent calcium carbonate equivalent); 1 percent basalt gravel; moderately alkaline (pH 8.0); gradual smooth boundary. (13 to 30 inches thick)
Bk2--51 to 60 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine tubular pores; strongly effervescent (20 percent calcium carbonate equivalent); 1 percent basalt gravel; moderately
alkaline (pH 8.0).
TYPE LOCATION: Bingham County, Idaho; about 2 1/2 miles northeast of Little Butte, about 8 miles northeast of Atomic City; about 2,500 feet south and 2,400 feet east of the northwest corner of sec. 26, T.3N., R.33E.; Latitude - 43 degrees, 33 minutes, 44 seconds north. Longitude - 112 degrees, 32 minutes, 4 seconds west.
RANGE IN CHARACTERISTICS:
The soil moisture control section is dry for one-half to three-fourths of the time when the soil temperature is above 41 degrees F; dry for 70 to 85 consecutive days.
Average annual soil temperature - 44 to 47 degrees F.
Average summer soil temperature - 62 to 66 degrees F.
Depth to argillic horizon - 4 to 10 inches
Depth to calcic horizon - 24 to 40 inches
Particle-size control section:
Total clay content - 27 to 35 percent
Carbonate clay - 0 to 5 percent, carbonate free clay - 25 to 35 percent
Rock fragments - 0 to 5 percent
Particles ranging in size from fine sand through gravel comprise 5 to 15 percent.
A horizons:
Value - 5 or 6 dry and 3 or 4 moist
Chroma - 1 through 3 dry or moist
Rock fragments - 0 to 5 percent
Reaction - slightly or moderately alkaline
Bt horizons:
Value - 5 or 6 dry and 3 or 4 moist
Chroma - 1 through 3 dry or moist
Rock fragments - 0 to 5 percent
Reaction - slightly or moderately alkaline
Btk horizon:
Value - 6 or 7 dry and 3 or 4 moist
Chroma - 1 through 4 dry or moist
Texture - SICL or SIL
Rock fragments - 0 to 5 percent
Calcium carbonate equivalent - 10 to 15 percent
Bk horizons:
Hue - 10YR or 2.5Y
Value - 6 through 8 dry and 4 or 5 moist
Chroma - 1 through 4 dry or moist
Texture - SIL, L, or CL
Rock fragments - 0 to 5 percent
Calcium carbonate equivalent - 15 to 25 percent
Reaction - moderately or strongly alkaline
COMPETING SERIES: These are no other series in this family. Soils in a closely related family are the McCain and the Power series. Power soils have a mesic soil temperature regime. McCain soils are petronodic.
GEOGRAPHIC SETTING: Menan soils formed in mixed alluvium and are in basins on lava plains. Slopes are 0 to 2 percent. Elevation ranges from 4,500 to 5,500 feet. The average annual precipitation ranges from 9 to 11 inches. Some additional moisture comes as run-on in spring. The average annual air temperature is about 43 to 45 degrees F. The frost free season is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Nargon, Atom, Deuce, and Techicknot soils. Nargon soils are moderately deep to basalt are coarse-loamy and occur on higher positions than Menan soils. Atom and Deuce soils do not have an argillic horizon and are on higher positions than Menan soils. In addition, Atom soils are Sodic and Deuce soils are shallow to bedrock. Techicknot soils are on similar positions but have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained; very slow to slow runoff; moderately slow permeability.
USE AND VEGETATION: Used primarily for range and wildlife. Vegetation is mainly basin big sagebrush and basin wildrye.
DISTRIBUTION AND EXTENT: Southeastern Idaho. The soils of this series are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Butte County Area, Idaho, 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 7 inches (the A1 and A2 horizons).
Argillic horizon - the zone from 7 to 38 inches (the Bt1, Bt2, Bt3 and Btk horizons).
Calcic horizon - the zone from 38 to 60 inches (the Bk1 and Bk2 horizons).
Particle-size control section - the zone from 7 to 27 inches (the upper 20 inches of the argillic horizon, the Bt1 and Bt2 horizons)
Depending on the amount of nodules in the Btk and Bk1 horizons, (common and many respectively) some pedons will classify as Petronodic if amount is over 20 percent and is a 6 inch layer within 40 inches of the surface.