LOCATION LEADORE            ID
Established Series
Rev. GPB/HBM
03/2003

LEADORE SERIES


The Leadore series consists of very deep and somewhat excessively drained soils formed in alluvium derived dominantly from quartzite. Leadore soils are on outwash fans and fan terraces. Permeability is moderate over very rapid. Slopes range from 1 to 8 percent. The average annual temperature is 38 degrees F and the average annual precipitation is about 9 inches.

TAXONOMIC CLASS: Sandy-skeletal, mixed, frigid Xeric Haplocalcids

TYPICAL PEDON: Leadore gravelly loam -- on a north facing slope of 3 percent, rangeland, at 6,330 feet elevation. (Colors are for dry soil unless otherwise stated. When described on April 28, 1982, the soil was moist throughout.)

A--0 to 3 inches; yellowish brown (10YR 5/4) gravelly loam, dark brown (10YR 3/3) moist; weak very fine subangular blocky structure parting to weak very fine and fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine interstitial pores; 15 percent pebbles; neutral (pH 7.2); clear wavy boundary. (1 to 5 inches thick)

Bw--3 to 9 inches; pale brown (10YR 6/3) gravelly loam, brown (10YR 4/3) moist; weak very fine, fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine interstitial pores; 15 percent pebbles; neutral (pH 7.3); gradual wavy boundary. (3 to 10 inches thick)

Bk--9 to 16 inches; pale brown (10YR 6/3) gravelly loam, brown (10YR 4/3) moist; weak very fine, fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine interstitial pores; 25 percent pebbles, 5 percent cobbles; lime and silica coatings less than 2mm thick on undersides of coarse fragments; slightly effervescent; slightly alkaline (pH 7.5); abrupt wavy boundary.(3 to 8 inches thick)

2Bkq1--16 to 27 inches; very pale brown (10YR 7/3) extremely cobbly loamy sand, light yellowish brown (10YR 6/4) moist; massive; slightly hard, very friable, nonsticky and nonplastic; loose; few very fine roots; many very fine and few fine and medium interstitial pores; 40 percent pebbles, 40 percent cobbles; lime and silica coatings less than 2mm thick on undersides of coarse fragments cementing fine pebbles and sand to coarse fragments; discontinuous silica cap less than 1mm thick present at 15 to 19 inch depths; violently effervescent; moderately alkaline (pH 7.9); gradual wavy boundary. (5 to 14 inches thick)

2Bkq2--27 to 60 inches; multicolored extremely cobbly sand; single grain; loose; common very fine roots as mats around pebbles and cobbles; many very fine, common fine and few medium interstitial pores; 40 percent pebbles, 35 percent cobbles, 5 percent stones; lime and silica coatings less than 2mm thick on undersides of coarse fragments cementing fine pebbles and sand to coarse fragments; slightly effervescent with areas of strongly effervescent; moderately alkaline (pH 8.3).

TYPE LOCATION: Lemhi County, Idaho; about 3.5 miles west of Leadore, Idaho;, about 1,700 feet north and 2,450 feet west from the southeast corner of section 36, T. 16 N., R. 25 E.

RANGE IN CHARACTERISTICS:

Average annual soil temperature - 39 to 41 degrees F.
Average summer soil temperature - 59 to 61 degrees F.
Control section - averages 3 to 12 percent clay
Rock fragments - 50 to 75 percent
Depth to secondary lime - 8 to 12 inches
Depth to calcic horizon - 10 to 20 inches

A horizon
Chroma - 3 or 4 dry

Bw horizon
Hue - 7.5YR or 10YR
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 through 6, dry and moist
Textures - GR-L, GRV-L, GRV-SL, GRV-SCL
Rock fragments - 15 to 40 percent

2Bkq horizon
Textures - CBX-LS, CBX-S, GRX-LS, GRX-LCOS, CBX-SL
Rock fragments - 65 to 85 percent

COMPETING SERIES: This is the Whiteknob series. Whiteknob soils are calcareous to the surface and contain 10 to 20 percent calcium carbonate equivalent in the surface.

GEOGRAPHIC SETTING: Leadore soils are on outwash fans and fan terraces. Elevations are 5,200 to 6,800 feet. Slopes are 1 to 8 percent. The soils formed in alluvium derived dominantly from quartzite. The climate is cold and moist in winter and dry in summer. Average annual precipitation is 8 to 11 inches. Average summer air temperature is 60 to 63 degrees F, and average annual air temperature is 37 to 39 degrees F. Frost free period is 45 to 75 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chamberlain, Whiteknob and Zer soils. Chamberlain and Zer soils have loamy-skeletal control sections and have a mollic epipedon.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow runoff; permeability is moderate over rapid.

USE AND VEGETATION: Rangeland. Some areas of Leadore soils are used for hayland, pastureland, and small grain crops. Vegetation is mainly Wyoming big sagebrush and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: East central Idaho. This series is moderately extensive.

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

SERIES ESTABLISHED: Lemhi County, Idaho 1999.

REMARKS: Diagnostic features recognized in this pedon are:

Ochric epipedon
Cambic horizon - the zone from 3 to 16 inches (Bw horizons)
Calcic horizon - the zone from 16 to 60 inches.
The particle-size control section is the zone from 10 to 40 inches (part of the Bw2, the 2Bkq1, and part of the 2BKq2 horizons)


National Cooperative Soil Survey
U.S.A.