LOCATION SANFELIPE IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, carbonatic, frigid Aridic Calcixerolls
TYPICAL PEDON: Sanfelipe gravelly loam--on a 5 percent smooth, south-facing slope at 6,550 feet in rangeland. (Colors are for dry soil unless otherwise noted. When described on September, 25, 1980, the soil was moist to 5 inches and dry from 5 to 60 inches.)
A1--0 to 5 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; weak thin platy structure parting to weak fine granular; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine irregular pores; 15 percent gravel; slightly alkaline (pH 7.5); clear smooth boundary. (3 to 8 inches thick)
A2--5 to 9 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine irregular pores; 25 percent gravel; slightly effervescent; slightly alkaline (pH 7.6); abrupt smooth boundary. (0 to 7 inches thick)
Bk1--9 to 20 inches; light gray (10YR 7/2) very gravelly loam, grayish brown (10YR 5/2) moist; weak medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine roots; few fine irregular pores; 40 percent gravel; prominent lime coatings on undersides of coarse fragments; violently effervescent (25 percent calcium carbonate equivalent); slightly alkaline (pH 7.8); clear smooth boundary. (8 to 15 inches thick)
Bk2--20 to 30 inches; grayish brown (10YR 5/2) extremely gravelly sandy loam, dark grayish brown (10YR 4/2) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; few very fine irregular pores; 60 percent gravel; prominent lime coatings on undersides of coarse fragments; violently effervescent (70 percent calcium carbonate equivalent); moderately alkaline (pH 8.3); gradual smooth boundary. (8 to 20 inches thick)
Bkq--30 to 60 inches; light brownish gray (10YR 6/2) extremely gravelly loamy coarse sand; dark grayish brown (10YR 4/2) moist; single grain; loose; 70 percent gravel; prominent lime and silica coatings 1 to 3 mm thick on undersides of coarse fragments; violently effervescent (65 percent calcium carbonate equivalent); slightly alkaline (pH 7.8).
TYPE LOCATION: Custer County, Idaho; about 3 miles north of the intersection on the Double Springs Pass Road and Idaho Highway 93, about 1,900 feet south and about 500 feet west of the northeast corner of section 24, T. 10 N., R. 21 E.
Latitude - 44 degrees, 07 minutes, 52 seconds North; Longitude - 113 degrees, 54 minutes, 45 seconds West.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 39 to 44 degrees F.
Depth to calcic horizon - 2 to 15 inches.
Mollic epipedon thickness - 8 to 12 inches.
Control section - Percent clay: 10 to 20.
Coarse fragments - average 40 to 65 percent (control section).
Calcium carbonate equivalent (averages) - 40 to 60 percent when 2 mm to 20 mm fractions are included.
Depth to the Bkq horizon - 25 to 40 inches.
A horizon
Value - 4 or 5 dry and 2 or 3 moist.
Chroma - 2 or 3 dry or moist.
Bk horizon
Value - 4 through 7 dry, 3 to 5 moist.
Chroma - 1 to 3 dry or moist.
Texture - GRV-L, GRV-SL, GRX-SL, GRX-COSL, GR-L.
Coarse fragments - 30 to 65 percent.
Reaction - slightly or moderately alkaline.
Bkq horizon
Value - 4 through 6 dry or moist.
Chroma - 1 or 2 dry or moist.
Texture - GRX-LCOS, GRX-LS, FRX-SL, GRV-SL.
Coarse fragments - 40 to 80 percent.
Reaction - slightly or moderately alkaline.
COMPETING SERIES: These are the Ansping and Ekim series. Ansping soils have a weakly cemented layer at 10 to 16 inches and a strongly cemented duripan at 40 to 55 inches. Ekim soils are moderately deep to limestone bedrock.
GEOGRAPHIC SETTING: Sanfelipe soils are on south and west-facing outwash fans and fan terraces. Elevations range from 6,000 to 7,000 feet. Slopes are 5 to 20 percent. The soils formed in alluvium derived dominantly from limestone and calcareous siltstones and sandstones. The climate is cold and moist in winter and spring and dry in summer. The mean annual precipitation is 9 to 13 inches. The mean annual air temperature is 37 to 42 degrees F. The frost-free period is 50 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Goosebury, Simeroi, Zeale and Zer. Goosebury, Simeroi and Zer soils are on outwash fans and fan terraces. Goosebury soils have ochric epipedons and cryic soil temperature regimes. Simeroi and Zer soils have ochric epipedons. Zeale soils are on mountains and have cryic soil temperature regimes.
DRAINAGE AND PERMEABILITY: Well drained. Slow runoff. Moderate permeability in the upper part and rapid in the lower part.
USE AND VEGETATION: Range. Vegetation is mainly Wyoming big sagebrush, three tip sagebrush and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: East-central, Idaho. These soils are of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Custer County, Idaho, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 9 inches (A1 and A2 horizons).
Calcic horizon - The zone from 9 to 30 inches (Bk1 and Bk2 horizons).
Particle-size control section - The zone from 10 to 40 inches (part of the Bk1, the Bk2 and part of the Bkq horizons).