LOCATION SMALL IDTentative Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Calcic Argixerolls
TYPICAL PEDON: Small gravelly silt loam - on an east-facing convex slope of 4 percent under sagebrush and grasses at 6,230 feet elevation. (When described on November 17, 1981, the soil was dry throughout profile. Colors are for dry soil unless otherwise noted.)
A1--0 to 4 inches; dark grayish brown (10YR 4/2) gravelly silt loam; very dark brown (10YR 2/2) moist; moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; common fine and very fine roots; common very fine tubular pores; 25 percent gravel; neutral (pH 7.2); clear wavy boundary. (3 to 5 inches thick)
Bt--4 to 7 inches; dark brown (10YR 4/3); gravelly silt loam; very dark grayish brown (10YR 3/2) moist; moderate medium and fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common fine and very fine, few medium roots; common very fine tubular pores; common thin clay films on ped faces and in pores; slight effervescence (11 percent calcium carbonate); 25 percent gravel; mildly alkaline (pH 7.4); clear wavy boundary. (3 to 8 inches thick)
Btk--7 to 15 inches; yellowish brown (10YR 5/4); very gravelly loam; dark brown (10YR 3/3) moist; strong medium and fine subangular blocky structure; soft, friable, slightly sticky and plastic; common fine and very fine, few medium roots; common fine and very fine tubular pores; few thin clay films on ped faces; strong effervescence (18 percent calcium carbonate); 40 percent gravel and 5 percent flagstones; mildly alkaline (pH 7.8); abrupt wavy boundary. (8 to 10 inches thick)
Bk--15 to 22 inches; very pale brown (10YR 7/3); extremely gravelly loam; brown (10YR 5/3) moist; massive; soft, very friable, slightly sticky and slightly plastic; few very fine roots; few very fine tubular pores; violent effervescence (25 percent calcium carbonate); 60 percent gravel and 5 percent flagstones; moderately alkaline (pH 8.0). (6 to 17 inches thick)
2R--22 inches; lime coated rhyolite.
TYPE LOCATION: Clark County, Idaho; about 6 miles west and 2 miles north of Small; 200 feet east and 1,850 feet north of the southwest corner of section. 31, T. 12 N., R. 34 E.
RANGE IN CHARACTERISTICS:
Textural control section (averages)
Clay - 18 to 26 percent
Coarse fragments - 35 to 50 percent
Percent carbonates (as calcium carbonate) - 15 to 32 percent
Profile ranges
Thickness of mollic epipedon - 14 to 18 inches
Depth to carbonates - 3 to 5 inches
Depth to argillic - 3 to 5 inches
Depth to bedrock - 20 to 40 inches
Average annual soil temperature - 40 to 44 degrees F.
A horizon
Color value, dry - 4 or 5
Value, moist - 2 or 3
Chroma, dry and moist - 2 or 3
Reaction - neutral to mildly alkaline
Bt horizon
Color value, dry - 4 or 5
Value, moist - 3 or 4
Chroma, dry and moist - 2 through 4
Textures - gravelly loam to extremely gravelly loam, or gravelly silt loam
Reaction - neutral to moderately alkaline
Cobbles - 0 to 10 percent
Calcium carbonates - 11 to 38 percent
Bk horizon
Color value, dry - 7 or 8
Value, moist - 5 or 6
Chroma, dry and moist - 2 or 3
Carbonates - 26 to 41 percent
Gravel - 60 to 80 percent
Cobbles - 5 to 10 percent
COMPETING SERIES: These are the Broad, Custco (T), Drage (T), Searla, and Sheep Creek, and Swampydraw (T) series. Broad soils have a soil temperature that ranges from 44 to 46 degrees F, and have a calcic horizon at 23 to 36 inches. Drage soils have less than 15 percent calcium carbonates and are very deep. Searla soils are greater than 40 inches deep, and contain 60 to 80 percent coarse fragments in the argillic. Sheep Creek soils have very cobbly B2t horizons and are underlain by limestone. Coarse fragments are limestone or calcareous sandstone. They receive 18 to 24 inches precipitation, have very cobbly Bt horizons and lack Btk horizons. The Custco and Swampydraw soils are greater than 40 inches to bedrock and more than 5 inches to lime.
GEOGRAPHIC SETTING: Small soils are on nearly level to undulating mountain slopes at elevations of 5,500 to 6,600 feet. Slopes range from 1 to 60 percent. Small soils formed in rhyolite, influenced by slope alluvium and loess from mixed sources. The average annual precipitation is 10 to 14 inches; the average annual air temperature is 38 to 42 degrees F; the average summer temperature ranges from 58 to 63 degrees F; and the frost-free season ranges from 75 to 95 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Deecree (T), Medicine (T), Shagel (T), Trumble (T), and Westindian (T) series. Deecree soils are on dissected alluvial fan terraces and are very deep. Medicine soils are very deep with contrasting particle sizes within the control section, and are on alluvial flood plains. Shagel soils are shallow to rhyolite bedrock and are on sloping mountain terraces. Trumble soils are moderately deep and have strongly contrasting particle sizes within the control section. The Westindian series is moderately deep to a thick indurated duripan, and is formed in mixed alluvium on dissected alluvial terraces.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; permeability is moderate.
USE AND VEGETATION: Dominant use is rangeland and wildlife habitat. Principal vegetation is low sagebrush, Bluebunch wheatgrass, prairie junegrass, and winterfat.
DISTRIBUTION AND EXTENT: Small soils are inextensive in southeastern Idaho.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Clark County, Idaho, 1981.
REMARKS: Name taken from nearby community.