LOCATION HUBTALF IDTentative Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Fluvaquentic Endoaquolls
TYPICAL PEDON: Hubtalf silt loam, on nearly level pastureland at an elevation of 1870 meters. When described on August 10, 1992, the soil was moist below 20 cm and saturated below 102 cm. (Color is for air dry soil unless otherwise noted).
A1--0 to 8 cm; dark grayish brown (10YR 4/2) silt loam, black (10YR 2/1) moist; strong coarse and very coarse platy structure parting to moderate fine subangular blocky; hard, very friable, moderately sticky and moderately plastic; many very fine and common fine roots; many very fine vesicular and common very fine tubular pores; slightly alkaline (pH 7.6); abrupt smooth boundary. (8 to 20 cm thick)
A2--8 to 20 cm; dark grayish brown (10YR 4/2) silty clay loam, black (10YR 2/1) moist; strong very thick platy structure parting to strong medium and coarse subangular blocky; hard, very friable, moderately sticky and moderately plastic; many very fine and few fine roots; many very fine and few fine tubular pores; slightly alkaline (pH 7.7); abrupt smooth boundary. (12 to 36 cm thick)
Bg--20 to 38 cm; dark gray (10YR 4/1) silty clay loam, very dark gray (10YR 3/1) moist; moderate fine and medium subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; common very fine and few fine roots; many very fine and few fine tubular pores; few fine prominent brown (7.5YR 4/3) redox concentrations; slightly alkaline (pH 7.7); clear smooth boundary. (0 to 20 cm thick)
Bkg1--38 to 58 cm; dark gray (10YR 4/1) silty clay loam, very dark gray (10YR 3/1) moist; moderate medium and coarse subangular blocky structure parting to moderate very fine and fine subangular blocky; hard, very friable, moderately sticky and moderately plastic; common very fine and few fine roots; many very fine and common fine tubular pores; secondary calcium carbonates disseminated and segregated into many fine and medium irregularly shaped soft filaments and seams; 8 percent calcium carbonate equivalent; violently effervescent; few fine prominent strong brown (7.5YR 4/6) redox concentrations; moderately alkaline (pH 8.0); clear smooth boundary. (10 to 25 cm thick)
Bkg2--58 to 102 cm; light brownish gray (10YR 6/2) silty clay loam, grayish brown (10YR 5/2) moist; weak medium and coarse subangular blocky structure parting to moderate very fine and fine subangular blocky; hard, very friable, moderately sticky and moderately plastic; few very fine roots; common very fine tubular and many very fine vesicular pores; secondary calcium carbonates disseminated and segregated into common fine and medium irregularly shaped soft filaments and seams; 45 percent calcium carbonate equivalent; violently effervescent; few fine prominent brown (7.5YR 5/4) redox concentrations; moderately alkaline (pH 8.4); gradual wavy boundary. (18 to 45 cm thick)
2Bkg3--102 to 152 cm; grayish brown (10YR 5/2) very fine sandy loam, dark grayish brown (10YR 4/2) moist; massive; hard, very friable, nonsticky and nonplastic; common very fine tubular and many very fine irregular pores; secondary calcium carbonates disseminated and segregated into few fine irregularly shaped soft filaments and seams; 16 percent calcium carbonate equivalent; violently effervescent; few fine distinct light brown (7.5YR 6/3) redox concentrations; moderately alkaline (pH 8.0).
TYPE LOCATION: Caribou County, Idaho; about 17 kilometers north of Soda Springs, Idaho; about 670 meters east and 549 meters north of the southwest corner of section 16, T. 7 S., R. 42 E.; China Hat, USGS topographic quadrangle; latitude 42 degrees 48 minutes 47.6 seconds north and longitude 111 degrees 33 minutes 20.8 seconds west, NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 3.3 to 5.6 degrees C.
Mean summer soil temperature: 15 to 18.3 degrees C.
Thickness of mollic epipedon and depth to the calcic horizon: 45 to 60 cm.
Depth to distinct or prominent redox concentrations: 20 to 45 cm.
Depth to secondary calcium carbonates: 20 to 45 cm.
Depth to the lithologic discontinuity (2Bkg horizon): 100 to over 152 cm
Particle-size control section:
Clay content: averages 25 to 32 percent.
Oi: (present in some pedons)
A horizon:
Hue: 10YR or 7.5YR.
Value: 2 to 4 dry and 2 or 3 moist
Chroma: 1 or 2 dry, and 1 moist.
Bg horizon:
Value: 2 to 4 dry, 2 or 3 moist.
Chroma: 1 or 2 dry and 1 moist
Texture: SIL or SICL
Clay content: 25 to 35 percent.
Bkg horizons:
Value: 4 to 7 dry, 3 to 5 moist.
Chroma: 1 or 2 dry or moist.
Texture: SIL or SICL.
Clay content: 18 to 35 percent.
Calcium carbonate equivalent: 5 to 45 percent.
2Bkg horizon: (absent in some pedons)
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 1 or 2 dry or moist
Texture: VFSL, SIL or GR-SICL
Redoximorphic features: few or common
Reaction: slightly to strongly alkaline
Rock fragments: 0 to 35 percent
COMPETING SERIES: These are the Seelovers, Sturgill and Vancecreek series. These soils lack any accumulation of calcium carbonate within the profile.
GEOGRAPHIC SETTING:
Landscape: Valleys
Landform: Low stream terraces and floodplains
Elevation: 1840 to 1910 meters
Slope: 0 to 1 percent
Parent material: Silty alluvium from loess and alluvium from mixed sources
Mean annual air temperature: 2.2 to 4.4 degrees C
Mean annual precipitation: 400 to 500 millimeters
Frost free period: 60 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Foundem, Lostine, and Ririe series. Foundem, Lostine, and Ririe soils are all well drained. They are on higher positions on the same landform as Hubtalf soils.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: Poorly
Runoff: Low
Saturated hydraulic conductivity: Moderately high
Flooding: Rare from April through June
USE AND VEGETATION:
Major uses: Pasture and some grass hay
Vegetation: Clover, sedges, rushes, and water tolerant grasses
DISTRIBUTION AND EXTENT: Southeastern Idaho; MLRA 13. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Caribou County, Idaho, 1993. Caribou County Area Idaho Soil Survey.
REMARKS: This was the original type location for the Chubbflat series. The soil temperature regime is now considered to be frigid. The Chubbflat series type location was moved to a more representative area and remains cryic.
Diagnostic properties recognized in the typical pedon are:
Mollic epipedon: 0 to 58 cm
Calcic horizon: 58 to greater than 152 cm with a decrease in calcium carbonate from 45 to 16 percent at about 102 cm
Aquic conditions: mollic epipedon from 0 to 58 cm and chroma of 1 with prominent redox concentrations from 20 to 58 cm.
Particle-size control section: 25 to 100 cm
Fluvaquentic feature: irregular decrease in organic carbon between 25 and 125 cm.