LOCATION SIBBETT ID
Tentative Series
Ird. BAG/GAH/EMM
05/2014
SIBBETT SERIES
The Sibbett series consists of very deep, very poorly drained soils that formed in alluvium. Sibbett soils are on valley floors. Slopes are 0 to 2 percent. Mean annual precipitation is about 500 millimeters and mean annual air temperature is about 2.2 degrees C.
TAXONOMIC CLASS: Fine-silty, mixed, superactive Argic Cryaquolls
TYPICAL PEDON: Sibbett peat, on a level 0 percent slope wet meadow (colors are for dry soil unless otherwise noted).
Oi--0 to 6 cm; dark yellowish brown (10YR 4/4) peat, dark yellowish brown (10YR 4/4) moist; fibric material; slightly decomposed sedges and grasses; many very fine roots; slightly acid (pH 6.4); clear smooth boundary.
Oe--6 to 16 cm; dark yellowish brown (10YR 3/4) mucky peat, dark yellowish brown (10YR 3/4) moist; rubbed and pressed hemic material; about 90 percent unrubbed fibers; 50 percent rubbed; many very fine and fine roots; slightly acid (pH 6.4); clear smooth boundary. (combined thickness of the O horizons is 5 to 20 cm)
A--16 to 22 cm; black (10YR 2/1) silt loam, black (10YR 2/1) moist; weak medium subangular blocky structure parting to common fine granular; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine irregular pores; neutral (pH 7.3); clear smooth boundary. (5 to 30 cm thick)
Btk1--22 to 37 cm; dark gray (2.5Y 4/1) silt loam, very dark gray (2.5Y 3/1) moist; weak medium prismatic structure parting to strong very fine angular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; 15 percent medium, irregular calcium carbonate masses throughout; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary.
Btk2--37 to 60 cm; light gray (2.5Y 7/1) silty clay loam, gray (2.5Y 6/1) moist; weak medium prismatic structure parting to strong medium angular blocky; moderately hard, friable, moderately sticky and moderately plastic; many very fine and common fine roots; many very fine tubular pores; 15 percent distinct clay films on all faces of peds; 10 percent coarse, irregular calcium carbonate masses throughout; violently effervescent; 5 percent medium manganese films; moderately alkaline (pH 8.4); clear wavy boundary. (combined thickness of the Btk horizons is 20 to 80 cm thick)
Bkg1--60 to 110 cm; light gray (10YR 7/2) silt loam, grayish brown (10YR 5/2) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; many very fine tubular pores; 15 percent medium, irregular calcium carbonate masses throughout; violently effervescent; 20 percent coarse, distinct, dark gray (2.5Y 4/1) iron depletions and 5 percent medium, prominent, yellowish brown (10YR 5/6) masses of oxidized iron; strongly alkaline (pH 8.6); gradual wavy boundary. (40 to 60 cm thick)
Bkg2--110 to 150 cm; light yellowish brown (10YR 6/4) very fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine tubular pores; 2 percent medium, irregular calcium carbonate masses throughout; strongly effervescent; 70 percent coarse, distinct, dark gray (2.5Y 4/1) iron depletions and 10 percent medium, prominent, yellowish brown (10YR 5/6) masses of oxidized iron; strongly alkaline (pH 8.6); gradual wavy boundary.
TYPE LOCATION: Caribou County, Idaho; about 4.5 kilometers southwest of the Grays Lake Guard Station and 1.2 kilometers north of State Highway 34. About 245 meters east and 560 meters south of the northwest corner of section 09, T.5 S., R.43 E.; Bear Island, USGS topographic quadrangle; latitude 43 degrees 00 minutes 06.0 seconds north and longitude 111 degrees 24 minutes 54.5 seconds west, NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 1.7 to 3.9 degrees C.
Mollic epipedon thickness: 20 to 40 cm
Depth to diagnostic features from the soil surface:
Depth to argillic horizon: 20 to 40 cm
Depth to calcic horizon: 20 to 80 cm
Depth to redox concentrations: 35 to 90 cm
Depth to redox depletions with chroma of 2 or less: 60 to 100 cm
Depth to apparent water table: 35 to 50 cm, from July to September.
O horizons
Value: 3 or 4 moist
Chroma: 2 to 4 moist
Slightly to moderately decomposed sedges, rushes, and grasses
Reaction: pH 6.2 to 7.6
A horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 2 or 3 dry or moist
Chroma: 1 or 2; dry or moist
Clay content: 18 to 27 percent
Reaction: pH 6.6 to 7.8
Bt horizon (when present)
Hue: 10YR or 2.5Y; dry or moist
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Texture: silt loam, silty clay loam or clay loam
Clay content: 24 to 35 percent
Reaction: pH 7.2 to 7.8
Btk horizons
Hue: 10YR or 2.5Y; dry or moist
Value: 4 to 8; dry or moist
Chroma: 1 to 3; dry or moist
Texture: silt loam, silty clay loam or clay loam
Clay content: 20 to 35 percent
Reaction: pH 7.9 to 8.6
Bkg1 horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 to 7; dry or moist
Chroma: 2 to 4; dry or moist
Texture: silt loam, silty clay loam or clay loam
Clay content: 18 to 30 percent
Reaction: pH 8.2 to 8.6
Bkg2 horizon (absent in some pedons)
Hue: 10YR or 2.5Y; dry or moist
Value: 4 to 7; dry or moist
Chroma: 3 or 4; dry or moist
Texture: very fine sandy loam, fine sandy loam or sandy loam
Clay content: 12 to 18 percent
Reaction: pH 8.2 to 8.6
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform: valley floors
Landscape: valleys
Elevation: 1940 to 1950 meters
Slope: 0 to 2 percent
Parent Material: alluvium from loess, metamorphic, and sedimentary rocks
Mean annual air temperature: 0.6 to 3.3 degrees C.
Mean annual precipitation: 450 to 550 millimeters
Frost-free period: 30 to 65 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Grayslake: have a histic epipedon greater than 150 cm and are on lower positions of the same landform.
Outlet: Do not have clay films and are on higher positions of the same landform.
Tepete: Has a histic epipedon greater than 40 cm. and occupy positions adjacent to Sibbett.
DRAINAGE AND PERMEABILITY:
Drainage class: very poorly
Saturated hydraulic conductivity: moderately high
Ponding: 5 to 25 cm April to June
USE AND VEGETATION:
Major uses: watershed, pastureland, and wildlife habitat
Vegetation: herbaceous cinquefoil, horsetail, Baltic rush, and other forbs and grasses
DISTRIBUTION AND EXTENT: Southeastern Idaho; MLRA 44B. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES PROPOSED: Caribou County, Idaho, 2014. The series name is from a historical trail.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: from 16 to 37 cm
Argillic horizon: from 37 to 60 cm
Calcic horizon: from 22 to 150 cm
Horizon with redox masses: from 37 to 60 cm
Horizon with redox depletions with chroma of 2 or less: 60 to 150 cm
Particle-size control section: 37 to 60 cm
Sibbett soils have a cryic temperature regime and an aquic moisture regime
National Cooperative Soil Survey
U.S.A.