LOCATION ELBOW              ID
Established Series
Rev. KRL/CLM
09/1999

ELBOW SERIES


The Elbow series consists of moderately deep to a duripan, well drained soils that formed in alluvium. Elbow soils are on outwash fans and fan terraces. Permeability is moderate above the duripan and very rapid below. Slopes are 1 to 4 percent. The average annual precipitation is about 12 inches and the average annual temperature is about 40 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Haploduridic Durixerolls

TYPICAL PEDON: Elbow gravelly loam-- on a 4 percent southwest facing slope at 6,100 feet elevation in rangeland. (Colors are for dry soil unless otherwise noted. When described on August 8, 1988 the soil was dry to 31 inches and slightly moist below 31 inches.)

A--0 to 5 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate very thick platy structure; soft, very friable, nonsticky and nonplastic; common very fine and few medium roots; few very fine tubular pores; 20 percent fine gravel; strongly effervescent; moderately alkaline (pH 7.9); abrupt wavy boundary. (3 to 6 inches thick)

Bk1--5 to 12 inches; brown (10YR 5/3) gravelly silt loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; soft, friable, nonsticky and nonplastic; common very fine and few medium roots; few very fine tubular pores; 20 percent fine gravel; common calcium carbonate coatings on coarse fragments; violently effervescent; moderately alkaline (pH 8.1); clear wavy boundary.

Bk2--12 to 17 inches; brown (10YR 5/3) very gravelly loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine roots; few very fine tubular pores; 35 percent gravel, 5 percent cobbles; common calcium carbonate coatings on coarse fragments; violently effervescent; strongly alkaline (pH 8.5); clear wavy boundary. (Combined thickness of the Bk horizons is 8 to 17 inches)

Bkq--17 to 23 inches; light brownish gray (10YR 6/2) extremely gravelly sandy loam, grayish brown (10YR 5/2) moist; weak very thick platy structure; slightly hard, friable, nonsticky and nonplastic; few very fine roots; few very fine tubular pores; 65 percent gravel, 10 percent cobbles; common calcium carbonate and silica coatings on coarse fragments; violently effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (5 to 10 inches thick)

Bkqm--23 to 31 inches; pinkish gray (7.5YR 7/2) indurated duripan, grayish brown (10YR 5/2) moist; massive; 45 percent gravel, 30 percent cobbles; violently effervescent; strongly alkaline (pH 8.8); abrupt wavy boundary. (3 to 9 inches thick)

B'kq1--31 to 35 inches; light gray (10YR 7/2) extremely cobbly coarse sandy loam, grayish brown (10YR 5/2) moist; massive, hard, firm, nonsticky and nonplastic; few very fine tubular pores; 40 percent gravel, 30 percent cobbles, 10 percent stones; common prominent calcium carbonate and silica coatings on coarse fragments; violently effervescent; strongly alkaline (pH 8.7); clear wavy boundary.

B'kq2--35 to 55 inches; multicolored extremely gravelly sand; single grain; loose, nonsticky and nonplastic; many fine irregular pores; 55 percent gravel, 30 percent cobbles; common prominent calcium carbonate and silica pendants on undersides of coarse fragments; strongly effervescent; strongly alkaline (pH 8.7); clear wavy boundary. (Combined thickness of the B'kq horizons is 18 to 35 inches)

B'k--55 to 60 inches; light gray (10YR 7/2) extremely gravelly coarse sand, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and few fine irregular pores; 60 percent gravel, 25 percent cobbles; common calcium carbonate coatings on coarse fragments; strongly effervescent; strongly alkaline (pH 8.6).

TYPE LOCATION: about 4 miles northeast of Leslie, Idaho; about 2,600 feet north and 850 feet east of the southwest corner of section 30, T. 7 N., R. 26 E.

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.

Average annual soil temperature - 39 to 43 degrees F.
Average summer soil temperature - 59 to 61 degrees F.
Thickness of mollic epipedon - 11 to 18 inches
Depth to duripan - 20 to 30 inches
Reaction - moderately or strongly alkaline
Particle-size control section: percent total clay averages - 10 to 18 percent carbonate free clay - 5 to 10
Depth to the calcic horizon - 2 to 6 inches

A horizon
Chroma - 2 or 3 dry or moist

Bk horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 or 3 dry or moist
Texture - GR-L, GR-SIL, GRV-L
Coarse fragments - 20 to 40 percent
Calcium carbonate equivalent - 15 to 20 percent

Bkq horizon
Value - 5 or 6 dry, 3 through 5 moist
Chroma - 2 or 3 dry or moist
Coarse fragments - 60 to 80 percent
Calcium carbonate equivalent - 15 to 20 percent

Bkqm horizon
Cementation - indurated in the upper part and strong or moderate cementation in the lower part

B'kq horizon
Rock fragments - 60 to 85 percent
Texture - CBX-COSL, GRX-COS, GRX-S
Clay content - 0 to 8 percent
Calcium carbonate equivalent - 10 to 20 percent

COMPETING SERIES: There are no other series in this family. The Loza soil in a closely related family is shallow to a duripan.

GEOGRAPHIC SETTING: Elbow soils are on outwash fans and fan terraces. These soils formed in alluvium. Slopes are 1 to 4 percent and elevations are 5,500 to 6,500 feet. The climate is cold and moist in winter and dry in summer. The average annual precipitation 11 to 13 inches; average annual temperature is 38 to 42 degrees F.; and the frost-free period is 70 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sanfelipe, Sparmo, Simeroi and Whiteknob soils. Sanfelipe soils are on outwash fans and fan terraces and lack duripans. Sparmo, Simeroi and Whiteknob soils are on outwash fans and fan terraces and lack mollic epipedons and duripans.

DRAINAGE AND PERMEABILITY: Well drained. Slow runoff. Moderate permeability above the duripan and very rapid below the pan.

USE AND VEGETATION: Rangeland. Natural vegetation is threetip sagebrush and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: East central Idaho. These soils 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:

Mollic epipedon - the zone from the soil surface to 17 inches (A, Bk1 and Bk2 horizons)

Calcic horizon - the zone from 5 to 23 inches (Bk1, Bk2 and Bkq horizons)

Duripan - the zone from 23 to 31 inches (Bkqm horizon)

Particle-size control section - the zone from 10 to 23 inches (part of Bk1, Bk2, Bkq horizons)


National Cooperative Soil Survey
U.S.A.