LOCATION FOURME IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Xeric Argicryolls
TYPICAL PEDON: Fourme loam, rangeland - on a 1 percent nearly level, southwest-facing slope under grass and shrub at 6,540 feet elevation. (Colors are for air-dry soil unless otherwise stated. When described on October 10, 1979 the soil was moist below 15 inches.)
A--0 to 5 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; 10 percent gravel; slightly acid (pH 6.4); clear smooth boundary. (5 to 10 inches thick)
BA--5 to 15 inches; yellowish brown (10YR 5/4) gravelly loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few faint clay films bridging sand grains; 15 percent gravel; neutral (pH 6.6) gradual wavy boundary. (5 to 10 inches thick)
Bt1--15 to 23 inches; yellowish brown (10YR 5/4) very gravelly sandy clay loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; slightly hard, friable, sticky and plastic; few faint clay films bridging sand grains; 30 percent gravel, 5 percent cobbles; slightly alkaline (pH 7.5); gradual wavy boundary. (6 to 16 inches thick)
Bt2--23 to 32 inches; multicolored, dominantly light yellowish brown (10YR 6/4) extremely gravelly sandy clay loam, multicolored, dominantly dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure parting to single grain; soft, very friable, slightly sticky and slightly plastic; few fine roots; few faint clay films bridging sand grains; 45 percent gravel, 20 percent cobbles; slightly alkaline (pH 7.7); gradual wavy boundary. (9 to 30 inches thick)
C--32 to 60 inches; multicolored extremely gravelly sand, multicolored, dominantly yellowish brown (10YR 5/4) moist; single grain; loose; 45 percent gravel, 20 percent cobbles; moderately alkaline (pH 8.0).
TYPE LOCATION: Fremont County, Idaho; about 18 miles east and 44 miles north of St. Anthony; 2,376 feet south and 1,188 feet west of the northeast corner of sec. 25, T.15N., R.43E.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 10 to 15 inches
Depth to base of argillic horizon - 30 to 60 inches or more
Moisture control section - dry for 45 to 60 consecutive days during the four months following the summer solstice. Particle-size control section
Clay content - 20 to 35 percent
Rock fragments - 35 to 60 percent
Average annual soil temperature - 36 to 42 degrees F.
Average summer soil temperature - 50 to 56 degrees F.
A horizon
Hue - 10YR or 7.5YR
Value - 3 through 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Reaction - slightly acid or neutral
BA and Bt horizons
Hue - 10YR or 7.5YR
Value - 3 through 6, dry or moist
Chroma - 3 through 6, dry or moist
Texture - GRV-SCL, GRX-CL, CL, GRV-CL, GRX-SCL, GR-L, or GR-SL Reaction - slightly acid through slightly alkaline
C horizon
Hue - variegated, 10YR or 7.5YR
Value - 3 though 6, dry or moist
Chroma - 4 through 6, dry or moist
Texture - GRX-S, GRX-LS, or GRX-COS
Reaction - neutral through moderately alkaline
COMPETING SERIES: These are the Blaine, Bowen, Buena Vista, Bullville (T), Chamberlain (T), Elwood, Ess, Ezbin (T), Fornor, Forsey, Fourmile, Geertsen, Hodden, Hoodle, Lagarita, Latigo (T), Libeg, Maciver (T), Nathale, Nathrop, Norriston, Nurkey (T), Packer, Parkview, Quander, Ratiopeak (T), Sawfork, Scuffe (T), Stopatoe (T), Spanpeak (T), Tagum (T), Tahquats, Teeler, Thiel, Winada, Woodhall, and Zeebar (T) soils. Blaine, Bowen, Buena Vista, Bullville, Elwood, Nathale, Nathrop, Parkview, Scuffe, Stopatoe, Tagum, Winada, and Woodhall soils have lithic or paralithic contact at depths shallower than 40 inches. Chamberlain, Fornor, Hodden, Hoodle, Latigo, Maciver, Nurkey, Quander, Ratiopeak, and Thiel soils have a layer of carbonate accumulation below the argillic horizon. Geertsen soils have an O horizon, an average annual soil temperature of 40 to 46 degree F. and are dry for 30 to 45 days following the summer solstice. Ess soils have an O horizon and a predominant summer soil moisture period. Ezbin soils have O horizons and have an average summer soil temperature of 45 to 47 degrees F. Forsey and Fourmile soils have average annual soil temperatures of 40 to 44 degrees F. Libeg soils have an ustic soil moisture regime. Norriston soils have sand and gravel at depths less than 20 inches, have average annual soil temperatures greater than 40 degrees F, and have a lithologic discontinuity in the profile. Packer soils are less than 21 inches deep to the base of the argillic horizon. Sawfork soils have a depth to the base of the argillic horizon of 10 to 20 inches and have calcareous material at 5 to 25 inches. Spanpeak soils have an 0 horizon and are dominated by schist or gneiss rock fragments. Tahquats soils are slightly acid to strongly acid in the argillic horizon. Teeler soils have depth to the base of the argillic horizon and depth to carbonates of 8 to 15 inches. Zeebar soils are dry in the moisture control section for 60 to 80 days consecutively and have a sandy loam, or dry loam texture in the substratum.
GEOGRAPHIC SETTING: Fourme soils are on alluvial fans, fan terraces and outwash plains. Slopes range from 0 to 4 percent. Elevation ranges from 6,100 to 7,000 feet. The soil formed in mixed alluvium derived dominantly from quartzite, limestone, sandstone, rhyolite, and mica schist. The average annual precipitation is about 18 to 26 inches. The average annual air temperature is about 34 to 40 degrees F. The frost-free season is 30 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Raynoldson, Sawtelpeak, Shotgun, Spliten, and Targhee soils. Raynoldson soils lack Bt horizons and are on alluvial fans and mountain slopes. Sawtelpeak soils are poorly drained and are on lacustrine deposits. Shotgun and Spliten soils are less than 40 inches deep to bedrock on loess covered basalt plains. Targhee soils are moderately deep on rhyolite flows.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately slow permeability in the upper part and very rapid below.
USE AND VEGETATION: Fourme soils are used principally for rangeland and grass hay production. The potential natural vegetation is Idaho fescue, bluebunch wheatgrass, Columbia needlegrass, prairie junegrass, arrowleaf balsamroot, and mountain big sagebrush.
DISTRIBUTION AND EXTENT: These soils are moderately extensive in southeast Idaho.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Fremont County, Idaho, Western Part, 1989.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to 15 inches (the A and BA horizons.)
Argillic horizon - the zone from 15 to 32 inches (the Bt1 and Bt2 horizons.)
Particle-size control section - the argillic horizon, the zone from 15 to 32 inches (the Bt1 and Bt2 horizons.)
Soil moisture regime - xeric