LOCATION FORMATION ID
Tentative Series
Rev. SM/FRK/MPR
04/2015
FORMATION SERIES
The Formation series consists of very deep, well drained soils that weathered from travertine residuum with some loess influence. Formation soils have slopes of 0 to 6 percent in drainageways and travertine terraces in valleys. The mean annual precipitation is about 450 millimeters, and the mean annual air temperature is about 3.3 degrees C.
TAXONOMIC CLASS: Coarse-loamy, carbonatic, frigid Typic Haploxerolls
TYPICAL PEDON: Formation loam, pastureland; on a 1 percent slope at 1872 meters. When described on July 18, 1989 the soil was dry throughout. (Colors are for dry soil unless otherwise noted.)
A1--0 to 10 cm; brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2) moist; moderate thick and very thick platy parting to moderate medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine and few fine roots; few very fine irregular, very fine vesicular, and fine tubular pores; 50 percent calcium carbonate equivalent; strongly effervescent; moderately alkaline (pH 8.3); abrupt smooth boundary
A2--10 to 23 cm; 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; 55 percent calcium carbonate equivalent; strongly effervescent; moderately alkaline (pH 8.3); clear smooth boundary
A3--23 to 43 cm; 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; 1 percent 4-to 8-mm snail shell fragments; 65 percent calcium carbonate equivalent; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary
C1--43 to 74 cm; 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; 1 percent 4- to 8-mm diameter snail shell fragments; 75 percent calcium carbonate equivalent; violently effervescent; strongly alkaline (pH 8.5); clear smooth boundary
C2--74 to 104 cm; 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; 75 percent calcium carbonate equivalent; violently effervescent; 5 percent 3- to 10-mm dendritic weakly cemented travertine nodules; strongly alkaline (pH 8.5); abrupt smooth boundary
C3--104 to 160 cm; 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; 75 percent calcium carbonate equivalent; violently effervescent; 2 percent travertine gravel; strongly alkaline (pH 8.6)
R--160 cm; travertine
TYPE LOCATION: Caribou County, Idaho; about 1.5 kilometers northwest of Conda, Idaho; about 655 meters north and 793 meters east of the southwest corner of sec. 9, T.8S., R.42E., Boise Meridian; Soda Springs, Idaho USGS quadrangle; 42.741667 north latitude, 111.554167 west longitude WGS84; UTM 454642 meters east, 4732277 meters north, zone 12
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 3.0 to 6.0 degrees C
Mean summer soil temperature - 15.0 to 18.0 degrees C
Depth to lithic contact - Greater than 150 cm
Thickness of mollic epipedon - 18 to 36 cm
Particle-size control section-
Clay content (total) - 5 to 15 percent
Clay content (carbonate) - 2 to 10 percent
Calcium carbonate equivalent - 50 to 90 percent
Rock fragments - 0 to 25 percent travertine gravel
A1 and A2 horizons
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 moist
Thickness - 18 to 36 cm
A3 horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 or 3 moist
Texture - Loam, fine sandy loam, sandy loam
Rock fragments - 0 to 25 percent travertine gravel and shell fragments
Thickness - 0 to 20 cm
C horizons
Hue - 10YR or 2.5Y
Value - 5 to 8 dry, 3 to 6 moist
Chroma - 2 to 6 dry or moist
Texture - Loam, fine sandy loam, sandy loam, loamy sand
Reaction - 8.0 to 9.0
Rock fragments - 0 to 25 percent travertine gravel and shell fragments
Thickness - Greater than 88 cm
COMPETING SERIES: There are no competing series
GEOGRAPHIC SETTING:
Parent material - Residuum weathered from travertine with some loess influence
Landscape - Valleys
Landform - Travertine terraces and drainageways
Slope - 0 to 6 percent
Elevation - 1,780 to 1,900 meters
Climate - Warm, dry summers; cool, moist winters
Mean annual precipitation - 400 to 500 mm
Mean annual air temperature - 2.0 to 5.0 degrees C
Frost free duration - 60 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Metole - Loamy-skeletal; smooth to slightly convex positions
Spaa - Lithic contact at 25 to 50 cm (shallow to travertine); slightly higher adjacent positions
Vertine - Moderately deep to a lithic contact (moderately deep to travertine); slightly higher positions and near travertine outcrops
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: (Ksat)
Drainage class - Well drained
Ksat - High to very high
USE AND VEGETATION:
Use - Livestock grazing, wildlife habitat, watershed, nonirrigated small grains
Potential natural vegetation - Mountain big sagebrush, threetip sagebrush, bluebunch wheatgrass, and Sandberg bluegrass
DISTRIBUTION AND EXTENT: Southeastern Idaho; MLRA 13; small extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Caribou County, Idaho, 1990; the name is taken from Formation Springs
REMARKS:
Particle-size control section - 25 to 100 cm
Mollic epipedon - 0 to 23 cm
Carbonatic mineralogy - Particle-size control section averages greater than 40 percent calcium carbonate equivalent
Calcium carbonate equivalent - Increases with depth, mainly travertine deposition
Soil temperature regime - Frigid
Soil moisture regime - Xeric
National Cooperative Soil Survey
U.S.A.