LOCATION SWALA ID
Tentative Series
Rev. SM/FRK/KMS
12/2015
SWALA SERIES
The Swala series consists of shallow, well drained soils formed in loess influenced residuum from travertine. Swala soils are found on slopes of 2 to 40 percent on travertine terraces. The mean annual precipitation is about 450 millimeters and the mean annual air temperature is about 3.3 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, carbonatic, frigid Lithic Haploxerolls
TYPICAL PEDON: Swala very stony silt loam, located on a south facing loess mantled dissected travertine terrace side slope with a slope of 32 percent and elevation of 1,885 meters. When described on August 16th, 1989 the soil was dry throughout (Colors are for dry soil unless otherwise noted)
A--0 to 8 cm; dark grayish brown (10YR 4/2) very stony silt loam, very dark brown (10YR 2/2) moist; weak fine and medium subangular blocky parting to weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; common very fine irregular and vesicular pores; few fine irregular soft secondary calcium carbonate masses and disseminated calcium carbonate; 35 percent calcium carbonate equivalent; moderately effervescent; 10 percent travertine gravel, 5 percent travertine cobbles and 20 percent travertine stones; moderately alkaline (pH 7.9); abrupt wavy boundary
Bk1--8 to 25 cm; grayish brown (10YR 5/2) gravelly silt loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; common very fine irregular pores; few fine irregular soft secondary calcium carbonate masses and disseminated calcium carbonate; 55 percent calcium carbonate equivalent; strongly effervescent; 10 percent travertine gravel, 5 percent travertine channers and 10 percent travertine flagstones; moderately alkaline (pH 8.2); clear wavy boundary
Bk2--25 to 38 cm; grayish brown (10YR 5/2) very gravelly loam, dark brown (10YR 3/3) moist; massive; soft, very friable, slightly sticky and slightly plastic; few very fine roots; common very fine and few fine irregular pores; many medium irregular soft secondary calcium carbonate masses and disseminated calcium carbonate; 65 percent calcium carbonate equivalent; violently effervescent; 20 percent travertine gravel, 15 percent travertine channers and 20 percent travertine flagstones; moderately alkaline (pH 8.3); abrupt wavy boundary
R--38 cm; very strongly cemented travertine
TYPE LOCATION: Caribou County, Idaho; about 12.5 kilometers southeast of Soda Springs, Idaho; 696 meters south and 367 meters west of the northeast corner, sec. 31, T.9S., R.43E.; Fossil Canyon, ID, USGS topographic quadrangle; latitude, 42.598584 north and longitude, -111.470594 west, WGS 84
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 3.3 to 5.6 degrees C. (frigid soil temperature regime)
Mean summer soil temperature - 15.0 to 18.3 degrees C.
Depth to lithic contact - 25 to 50 cm
Thickness of mollic epipedon - 18 to 40 cm
Particle-size control section-
Clay content - 10 to 15 percent
Calcium carbonate equivalent - 60 to 75 percent
Rock fragments (travertine) - 35 to 70
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Calcium carbonate equivalent - 20 to 40 percent
Reaction - 7.8 to 8.2
Thickness - 7 to 18 cm
Bk horizons
Value - 5 to 7 dry, 2 to 4 moist
Chroma - 2 or 3 dry or moist
Fine earth texture - Silt loam, loam, sandy loam
Rock fragments (travertine) - 35 to 70 percent total
Calcium carbonate equivalent - 45 to 75 percent
Reaction - 8.0 to 8.4
Thickness - 18 to 35 cm
COMPETING SERIES:
Hymas - Lack B horizons with identifiable secondary calcium carbonate accumulations
GEOGRAPHIC SETTING:
Parent material - Loess influenced colluvium and residuum from travertine
Landscape - Valleys
Landform - Loess covered travertine terraces
Slope - 2 to 40 percent
Elevation - 1,765 to 1,900 meters
Climate - Warm, dry summers; cool, wet winters
Mean annual precipitation - 400 to 500 millimeters
Mean annual air temperature - 2.2 to 4.4 degrees C.
Frost free duration - 60 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Iphill - very deep; well drained on south and west-facing convex slopes on loess covered travertine terraces
Rexburg - very deep; well drained on west-facing smooth slopes on loess covered travertine terraces
Spaa taxadjunct - moderately deep; less than 35 percent coarse fragments in the particle-size control section; on similar positions as Swala
Wospring - very deep; poorly drained on higher positions of travertine terraces near springs
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: (Ksat)
Drainage class - Well drained
Ksat - Moderate
USE AND VEGETATION:
Use - Wildlife habitat
Potential natural vegetation - Mountain big sagebrush, bluebunch wheatgrass, and bitter brush
DISTRIBUTION AND EXTENT: Southeastern Idaho; MLRA 13; small extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Caribou County, Idaho, 2015; the name is coined
REMARKS:
Particle-size control section - 25 to 38 cm
Mollic epipedon - 0 to 38 cm
Xeric moisture regime
Carbonatic mineralogy - particle-size control section averages greater than 40 percent calcium carbonate equivalent
A significant portion of the calcium carbonate increase is due to the larger amount of less than 20mm fragments of travertine
Lithic contact - 38 cm very strongly cemented travertine
National Cooperative Soil Survey
U.S.A.