LOCATION SIPHONLAKE IDEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Typic Haploxerolls
TYPICAL PEDON: Siphonlake sandy loam -- on a 52 percent convex north-facing slope at 3,050 feet elevation in rangeland. When described on August 10, 1994, the soil was dry throughout. (Colors are for air-dry soil unless otherwise noted.)
A1--0 to 2 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium and coarse roots; many very fine and fine irregular pores; 5 percent fine gravel; slightly acid (pH 6.2); clear smooth boundary.
A2--2 to 6 inches; dark grayish brown (10YR 4/2) sandy loam, very dark brown (10YR 2/2) moist; weak medium platy structure parting to moderate fine granular; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium and coarse roots; common very fine and fine tubular pores; 5 percent fine gravel; slightly acid (pH 6.1); gradual wavy boundary. (combined A horizon - 5 to 12 inches thick)
BA--6 to 19 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; moderate medium and coarse subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; common very fine and fine tubular pores; 5 percent fine gravel; moderately acid (pH 6.0); clear wavy boundary. (0 to 15 inches thick)
Bt--19 to 31 inches; light yellowish brown (10YR 6/4) coarse sandy loam, dark yellowish brown (10YR 4/4) moist; strong fine and medium subangular blocky structure; very hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; common very fine and fine tubular pores; few faint clay films bridging sand grains and in pores; few continuous lamellae 2 to 5 mm thick with common distinct clay films bridging sand grains, on faces of peds, and in pores; 10 percent fine gravel; slightly acid (pH 6.2); gradual wavy boundary. (9 to 17 inches thick)
BC--31 to 42 inches; very pale brown (10YR 7/4) coarse sandy loam, yellowish brown (10YR 5/4) moist; moderate fine and medium subangular blocky structure; very hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; common very fine and fine tubular pores; 10 percent fine gravel; moderately acid (pH 6.0); clear smooth boundary. (7 to 24 inches thick)
C--42 to 47 inches; very pale brown (10YR 8/2) fine gravelly loamy coarse sand, grayish brown (10YR 5/2) moist; single grain; loose, nonsticky and nonplastic; few very fine, fine and medium roots; many very fine and fine irregular pores; 15 percent fine gravel; moderately acid (pH 6.0); abrupt wavy boundary. (0 to 10 inches thick)
Cr--47 to 60 inches; very pale brown (10YR 8/2) consolidated stratified sandy lacustrine deposits.
TYPE LOCATION: Boise County, Idaho; about 3 miles south and 1.5 mile west of Horseshoe Bend; 2,350 feet south and 2,250 feet west of the northeast corner of section 4, T.6 N., R.2 E.; USGS Horseshoe Bend Quadrangle; Latitude - 43 degrees, 53 minutes, 16 seconds N. and Longitude - 116 degrees, 13 minutes, 21 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 10 to 20 inches
Depth to paralithic contact - 40 to 60 inches
Particle-size control section - 8 to 18 percent clay; 0 to 10 percent rock fragments
Moisture control section - dry for 60 to 90 consecutive days following the summer solstice
Average annual soil temperature - 48 to 52 degrees F.
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Clay content - 10 to 18 percent
Rock fragments - 0 to 5 percent fine gravel
Reaction - slightly acid or neutral
BA horizon (when present)
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Texture - L or SL
Clay content - 8 to 18 percent
Rock fragments - 0 to 5 percent fine gravel
Reaction - moderately acid though neutral
Bt horizon
Value - 4 through 6 dry, 3 through 5 moist
Chroma - 2 through 4 dry or moist
Texture - L, SL or COSL
Clay content - 10 to 18 percent
Rock fragments - 0 to 10 percent fine gravel
Reaction - moderately acid though neutral
BC horizon
Value - 6 through 8 dry, 4 or 5 moist
Chroma - 2 through 4 dry or moist
Texture - COSL or SL
Clay content - 7 to 15 percent
Rock fragments - 0 to 20 percent fine gravel
Reaction - moderately acid though neutral
COMPETING SERIES: These are the Anders, Brief, Chenoweth, Cleverly, Cushenbury, Duart, Hesslan, Knutsen, Newbon, Panamint, Patemos (T), Rimforest (T) and Wato series. Anders soils are moderately deep to a lithic contact. Brief, Cleverly and Newbon soils are very deep and have more than 15 percent rock fragments in the particle-size control section. Chenoweth soils are very deep and have an average annual soil temperature of 53 to 54 degrees F. Cushenbury soils are moderately deep to a paralithic contact and have an average annual soil temperature of 53 to 59 degrees F. Duart and Hesslan soils are moderately deep to a paralithic contact. Knutsen soils are very deep and have 2C horizons between 30 and 60 inches. Panamint soils are moderately deep to a paralithic contact and have an average annual soil temperature of greater than 52 degrees F. Patemos, Rimforest and Wato soils are very deep and are dry for more than 90 consecutive days following the summer solstice.
GEOGRAPHIC SETTING: Siphonlake soils are on convex north and east-facing or concave south and west-facing hill backslopes and shoulders commonly associated with landslides at elevations of 2,750 to 4,550 feet. Slopes range from 35 to 65 percent. The soils formed in colluvium and residuum from sandy lacustrine deposits. The average annual precipitation is 14 to 20 inches. The average annual temperature is 46 to 50 degrees F. The frost-free period is 100 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Van Dusen and Solarview soils. Solarview soils are shallow to a paralithic contact and occur on convex steep south-facing slopes of lacustrine foothills. Van Dusen soils are very deep and have mollic epipedons that are more than 20 inches thick and occur on concave north and east facing lacustrine foothills.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Siphonlake soils are used mainly for rangeland. Native vegetation is xeric big sagebrush, bluebunch wheatgrass and on north aspects Idaho fescue.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 10. Siphonlake soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Boise County Area, Idaho, Parts of Ada and Boise Counties, 2005.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon - zone from the surface to 19 inches (A1, A2 and BA horizons)
Cambic horizon - zone from 19 to 42 inches (Bt and BC horizons); the Bt horizon lacks the clay increase necessary for an argillic horizon
Particle-size control section - zone from 10 to 40 inches
Paralithic contact - at 47 inches (Cr horizon)
Soil moisture regime - xeric
ADDITIONAL DATA: Reference sample no. S94ID-015-008 (NSSL pedon 95Z168), NSSL, 1/96.