LOCATION FORMATION IDTentative Series
TAXONOMIC CLASS: Coarse-loamy, carbonatic Xeric Calcicryolls
TYPICAL PEDON: Formation loam, pastureland; on a 1 percent slope at 6,140 feet elevation. When described on July 18, 1989 the soil was dry throughout. (Color is for air dry soil unless otherwise noted.)
A1--0 to 4 inches; brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2) moist; moderate coarse and very coarse platy structure parting to moderate medium subangular blocky; soft, very friable, nonsticky and slightly plastic; common very fine and few fine roots; few very fine irregular, few very fine vesicular and few fine tubular pores; strongly effervescent (50 percent calcium carbonate equivalent); disseminated lime; moderately alkaline (pH 8.3); abrupt smooth boundary. (2 to 5 inches thick)
A2--4 to 9 inches; brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine and few fine roots; few very fine irregular and common very fine tubular pores; strongly effervescent (45 percent calcium carbonate equivalent); disseminated lime; moderately alkaline (pH 8.3); clear smooth boundary. (5 to 9 inches thick)
Bk1--9 to 17 inches; brown (10YR 5/3) loam, dark grayish brown (10YR 4/2) moist; moderate medium and coarse subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; common very fine roots; few very fine irregular and tubular pores; few small snail shells; violently effervescent (65 percent calcium carbonate equivalent); disseminated lime; moderately alkaline (pH 8.4); abrupt smooth boundary. (4 to 11 inches thick)
Bk2--17 to 29 inches; very pale brown (10YR 7/3) fine sandy loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, friable, nonsticky and slightly plastic; few very fine roots; few very fine irregular and tubular pores; few small snail shells; violently effervescent (85 percent calcium carbonate equivalent); disseminated lime; strongly alkaline (pH 8.5); clear smooth boundary. (6 to 15 inches thick)
Bk3--29 to 41 inches; light yellowish brown (10YR 6/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine irregular and few very fine tubular pores; violently effervescent (55 percent calcium carbonate equivalent); few fine irregularly shaped soft lime filaments and soft lime masses; 2 percent gravel (travertine tubes); strongly alkaline (pH 8.5); abrupt smooth boundary. (5 to 15 inches thick)
C--41 to 63 inches; brownish yellow (10YR 6/6) loamy sand, dark yellowish brown (10YR 4/6) moist; single grain; loose; few very fine roots; many very fine irregular and vesicular pores; violently effervescent (50 percent calcium carbonate equivalent); disseminated lime; 2 percent gravel (travertine fragments); strongly alkaline (pH 8.6).
TYPE LOCATION: Caribou County, Idaho; about 1 mile northwest of Conda; about 2,150 feet north and 2,600 feet east of the southwest corner of sec. 9, T.8S., R.42E. 42 degrees, 44 minutes, 30 seconds north latitude, 111 degrees, 33 minutes, 15 seconds west longitude.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 7 to 14 inches
Depth to calcic horizon - 5 to 14 inches
Depth to travertine - 40 to 60 inches or more
Average annual soil temperature - 36 to 38 degrees F
Particle-size control section:
Clay content - averages 5 to 15 percent
A horizons
Chroma - 2 or 3 moist
Bk horizons
Hue - 10YR or 2.5Y
Value - 5 through 8 dry, 3 through 6 moist
Chroma - 2 through 4 dry or moist
Reaction - moderately alkaline through strongly alkaline
Texture - L, FSL, SL or LS
C horizon (absent in some pedons)
Hue - 10YR or 2.5Y
Value - 6 through 8 dry, 4 through 6 moist
Chroma - 6 or 7 dry or moist
Reaction - moderately or strongly alkaline
COMPETING SERIES: There are no other soils in the same family. A soil in a closely related family is the Escarlo series. The Escarlo soils are fine-loamy and have 30 to 40 percent volcanic glass in the sand and coarse silt fraction of the A horizon..
GEOGRAPHIC SETTING: Formation soils are in wide, old drainageways and on fan terraces. Slopes range from 0 to 2 percent. Elevations range from 6,000 to 6,200 feet. The soils formed in travertine residuum with some loess influence. Average annual precipitation is 17 to 19 inches, average annual temperature is 35 to 37 degrees F. and the frost free period is 45 to 65 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chinahat and Lantonia soils. Chinahat and Lantonia soils have a coarse-silty particle size control section. Chinahat soils are on south and west-facing convex slopes on loess covered basalt plains. Lantonia soils are on north and east-facing smooth to concave slopes on loess covered basalt plains and hills.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately rapid permeability.
USE AND VEGETATION: Formation soils are used for nonirrigated cropland. Typical crops consist of small grains.
DISTRIBUTION AND EXTENT: Southeastern Idaho. The soils of this series are of small extent.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Caribou County, Idaho, 1990. The name is taken from Formation Springs.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 9 inches (the A1 and A2 horizons).
Calcic horizon - The zone from 9 to 41 inches (the Bk1, Bk2 and Bk3 horizons).
Particle-size control section - The zone from 10 inches to 40 inches (part of the Bk1, the Bk2 and part of the Bk3 horizons).
Xeric moisture regime.