LOCATION LASCHANCE               ID

Tentative Series
IRD: FRK/TDT
06/2011

LASCHANCE SERIES

The Laschance series consists of shallow, well drained soils formed in colluvium derived from dolomite, limestone, and calcareous sandstone. Laschance soils are on mountain slopes and hill slopes. Slopes range from 8 to 70 percent. The mean annual precipitation is about 456 mm, and the mean annual air temperature is about 4.4 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Lithic Haploxerolls

TYPICAL PEDON: Laschance gravelly loam, 68 percent slope, northwest aspect, in rangeland at 1,886 meters. (colors are for dry soil unless otherwise noted).

A--0 to 22 cm; very dark grayish brown (10YR 3/2) gravelly loam, very dark brown (10YR 2/2) moist; weak very fine and fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots; common very fine and fine irregular pores; 5 percent fine and 25 percent medium gravel; neutral (pH 7.2); clear wavy boundary. (7 to 22 cm thick)

Bk1--22 to 28 cm; brown (10YR 4/3) very gravelly loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine and common fine and medium roots; common very fine and fine irregular pores; very slightly effervescent; common fine and medium secondary calcium carbonate coats on the bottoms of rock fragments; 5 percent fine gravel, 30 percent medium and coarse gravel, and 5 percent cobbles; neutral (pH 7.2); abrupt irregular boundary. (6 to 25 cm thick)

Bk2--28 to 39 cm; brown (10YR 5/3) extremely cobbly loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; common very fine and fine irregular pores; slightly effervescent; common fine and medium secondary calcium carbonate coats around rock fragments; 30 percent medium and coarse gravel, 50 percent cobbles, and 5 percent stones; slightly alkaline (pH 7.6); abrupt wavy boundary. (0 to 11 cm thick)

R--39 cm; dolomite bedrock.

TYPE LOCATION: Caribou County, Idaho; about 10 kilometers west of Soda Springs; about 170 meters east and 375 meters north of the SW corner of sec. 6, T. 9 S., R. 41 E.; Alexander, USGS topographic quadrangle; latitude, 42 degrees 40 minutes 1.19 seconds north and longitude, 111 degrees 43 minutes 7.09 seconds west, NAD 83.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 2.8 to 5.6 degrees C.
Mean summer soil temperature: 15.0 to 18.3 degrees C.
Thickness of mollic epipedon: 18 to 40 cm.
Depth to bedrock: 25 to 50 cm.
Calcium carbonate equivalent: 1 to 5 percent

Particle-size control section:
Clay content: averages 7 to 14 percent
Rock fragment content: averages 40 to 80 percent


A horizon
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 2 or 3 dry or moist
Clay content: 5 to 15 percent
Rock fragment content: 15 to 35 percent total rock fragments; 15 to 35 percent gravel; 0 to 5 percent cobbles

Bk1 horizon
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3 dry or moist
Texture: loam, fine sandy loam, or sandy loam with 30 to 55 percent gravel; 5 to 40 percent cobbles; 0 to 5 percent stones
Clay content: 5 to 18 percent
Rock fragment content: 40 to 85 percent total rock fragments
Reaction: neutral to slightly alkaline

Bk2 horizon (absent in some pedons)
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 to 4 dry or moist
Texture: loam, fine sandy loam, or sandy loam with 15 to 30 percent gravel; 45 to 65 percent cobbles; 0 to 10 percent stones
Clay content: 5 to 16 percent
Rock fragment content: 65 to 85 percent total rock fragments

COMPETING SERIES:
Agassiz (UT): have 18 to 27 percent clay in the particle-size control section.
Alomax (CA): have an aridic moisture regime that borders on xeric and the series needs reclassification to Aridic Lithic subgroup.
Anatone (WA): lack accumulations of secondary calcium carbonate.
Bluecanyon (OR): lack accumulations of secondary calcium carbonate.
Bocker (WA): are 10 to 25 centimeters deep to a lithic contact.
Dipcreek ID): lack accumulations of secondary calcium carbonate.
Falula (UT): have a calcic horizon.
Foxol (UT): are slightly to moderately acid throughout the soil.
Gando (NV): have an aridic moisture regime bordering on xeric and the series needs reclassification to Aridic Lithic subgroup.
Gomine (UT): have more than 20 percent clay in the particle-size control section.
Grink (NV): have a calcic horizon.
Kenypeak (CA): are slightly to moderately acid and lack accumulations of secondary calcium carbonate.
Little Pole (UT): have greater than 18 percent clay in the particle-size control section and have accumulations of illuviated clay.
Nayrib (ID): have a lithic contact at 10 to 25 centimeters.
Onaqui (UT): have 18 to 27 percent clay in the particle-size control section.
Rexmont (UT): have 18 to 27 percent clay in the particle-size control section.
Starglade (OR): have a lithic contact at 10 to 25 centimeters and have an influence of ash throughout the profile.
Swanner (ID): have violently effervescent accumulations of disseminated secondary calcium carbonate in the lower part of the soil profile.
Van Wagoner (UT): lack accumulations of secondary calcium carbonate.

GEOGRAPHIC SETTING:
Parent material: colluvium derived dominantly from dolomite, limestone, and calcareous sandstone.
Landscape: Mountains and hills.
Landform: Smooth to slightly convex positions on mountain slopes and hill slopes.
Slopes: 8 to 70 percent.
Elevation: 1,690 to 2,285 meters.
Mean annual temperature: 2.8 to 5.6 degrees C
Mean annual precipitation: 406 to 508 millimeters
Frost-free period: 60 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ireland, Jimsage, Rexburg, and Ricrest soils. Ireland, Jimsage, and Ricrest soils are well drained and are on smooth to slightly concave areas on mountain slopes and backslopes of hills. Ireland soils are moderately deep and have a calcic horizon. Jimsage and Ricrest soils are very deep, have a mollic epipedon greater than 50 centimeters thick, and have a calcic horizon. Rexburg soils are well drained and are on footslopes and basalt plains. Rexburg soils are very deep, have a coarse-silty particle-size control section, and a calcic horizon.

DRAINAGE AND PERMEABILITY:
Drainage class: Well drained
Runoff: Medium to high
Saturated hydraulic conductivity: Moderate or moderately rapid.

USE AND VEGETATION:
Major uses: Wildlife habitat and livestock grazing.
Vegetation: Mainly bluebunch wheatgrass and mountain big sagebrush.

DISTRIBUTION AND EXTENT: Southeastern Idaho; MLRA 13. The soils are of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES PROPOSED: Caribou County Area, Idaho; 2011.

REMARKS: Diagnostic properties recognized in this pedon are:
Mollic epipedon: 0 to 39 cm (A, Bk1 and Bk2 horizons)
Particle size control section: 25 to 39 cm with weighted average rock fragment content of 75%
Lithic contact: 39 cm (R horizon).
Soil temperature regime: Frigid
Soil moisture regime: Xeric

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National Cooperative Soil Survey
U.S.A.