LOCATION MOLYNEUX IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Ultic Argixerolls
TYPICAL PEDON: Molyneux loam - on 3 percent east facing slope at an elevation of 5,520 feet in rangeland. When described on September 27, l978, the soil was dry throughout. (Colors are for dry soil unless otherwise noted.)
A1--0 to 8 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; moderate fine to medium platy structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine, medium and coarse roots; common very fine irregular pores; 10 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (3 to 10 inches thick)
A2--8 to 13 inches; brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2) moist; moderate fine to medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine, fine, medium and coarse roots; many very fine, fine, and medium irregular pores; 5 percent gravel; slightly acid (pH 6.2); abrupt wavy boundary. (5 to 10 inches thick)
Bt1-13 to 24 inches; yellowish brown (10YR 5/4) clay loam, dark yellowish brown (10YR 3/4) moist; moderate medium prismatic structure; hard, friable, moderately sticky and moderately plastic; few very fine, fine, medium, and coarse roots; many fine and medium tubular pores; many faint clay films on faces of peds and in pores; 10 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (10 to 25 inches thick)
Bt2--24 to 50 inches; yellowish brown (10YR 5/4) clay loam, dark yellowish brown (10YR 4/4) moist; strong fine to medium angular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine and medium roots; many fine and medium irregular pores; many faint clay films on faces of peds; 10 percent gravel; neutral (pH 6.6); clear wavy boundary. (15 to 30 inches thick)
Bt3--50 to 75 inches; yellowish brown (10YR 5/4) gravelly sandy clay loam, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine, fine, and medium roots; many fine and medium irregular pores; many faint clay films on faces of peds; 15 percent gravel; neutral (pH 6.8).
TYPE LOCATION: Blaine County, Idaho about 3 miles west and 1 mile north from Hailey; 500 feet south and 1,000 feet west of the northeast corner of sec. 24, T. 2 N., R. 17 E. Latitude - 43 degrees, 29 minutes, 36 seconds North; Longitude - 114 degrees, 21 minutes, 45 seconds West.
RANGE IN CHARACTERISTICS:
Depth to bedrock - more than 60 inches
Average annual soil temperature - 42 to 47 degrees F.
Reaction - Slightly acid to neutral
Thickness of mollic epipedon - 10 to 20 inches
Base saturation (upper 75 cm) by sum of cation - 50 to 75 percent
A horizon
Color value, dry - 4 or 5
Value, moist - 2 or 3
Chroma - 2 to 4 dry, 2 or 3 moist
Clay content - 10 to 15 percent
Coarse fragments - 0 to 10 percent
Bt1 and Bt2 horizons
Color value, dry - 3 through 6
Value, moist - 2 through 5
Chroma, moist or dry - 2 through 4
Clay content - 22 to 35 percent
Coarse fragments - 0 to 25 percent
Texture - CL, SIL, SCL, L, CB-L, GR-SCL, CB-CL
More than 30 percent fine sand or coarser
Bt3 horizon
Hue - 10YR or 7.5YR
Color value, dry - 5 to 7
Color value, moist - 3 through 6
Chroma, moist or dry - 3 or 4
Texture - GR-CL, GR-SCL, CL, L, CB-SCL
Coarse fragments - 5 to 25 percent
COMPETING SERIES: These are the Buffom, Carmack, Elkcreek, Johnson, Lidos, Mojo, Muldoon, Simonton, Skelter, Suloaf, and Trojan series. Buffom soils have bedrock at 40 to 60 inches. Carmack soils have an 0 horizon and less than 30 percent sand coarser than very fine sand in the control section. Elkcreek and Mojo soils are 20 to 40 inches deep to bedrock. Johnson and Trojan soils have hues of 7.5YR and 5YR in the argillic horizon. Muldon soils have less thank 30 percent fine sand or coarser and less than 5 percent rock fragments in the upper part of the particle-size control section. Skelter soils have stratified alluvium in the lower part of the particle-size control section and have strongly or extremely acid reaction in the lower part of the series control section. Trojan soils have an 0 horizon, and are dry more than 80 consecutive days. Suloaf soils have bedrock between 40 and 60 inches. Simonton soils have a solum that is 30 to 40 inches thick. Lidos soils have an 0 horizon and are slightly acid to strongly acid throughout.
GEOGRAPHIC SETTING: Molyneux soils are on fan terraces, basalt plains, canyon sides, and foothills. Slopes range from 2 to 35 percent. Elevation ranges from 4,800 to 6,000 feet. The soil formed in alluvium and colluvium from mixed sources. The average annual precipitation is 12 to 16 inches, most of which falls as snow and early spring rain. The average annual temperature is about 40 to 45 degrees F. The frost-free season is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Bringmee, Drage, Little Wood, and McCarey soils. Bringmee soils have mollic epipedons thicker than 20 inches. Drage and Little Wood soils contain more than 35 rock fragments in the B2t horizons. McCarey soils are moderately deep and are on basalt plains. Bringmee and Little Wood soils are on stream terraces. Drage soils are on fan terraces.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately slow permeability.
USE AND VEGETATION: Mainly used for range, irrigated hay and pasture, and some cropland. Vegetation is mountain big sagebrush basin big sagebrush, Idaho fescue; and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: South-central Idaho. This series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Blaine County, Idaho, 1985.
REMARKS: Diagnostic horizons and features recognized in this series are:
Mollic epipedon - zone from the soil surface to about 13 inches (A1 and A2 horizons)
Argillic horizon - zone from about 13 to 50 inches (Bt1 and Bt2 horizons)
Base saturation - 50 to 75 percent in upper 75 cm.
Particle-size control section - 13 to 33 inches (Bt1 and Bt2 horizons)