LOCATION LYONSBRIDGE MT
Established Series
TDL-EW-RJS
01/2012
LYONSBRIDGE SERIES
The Lyonsbridge series consists of very deep, well drained soils that formed in alluvium and/or lake sediments. These soils occur on alluvial fans, fan remnants and lakebeds. Slopes are 0 to 4 percent. Mean annual precipitation is about 390 millimeters and mean annual air temperature is about 3 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Ustic Calcicryepts
TYPICAL PEDON: Lyonsbridge fine sandy loam, in rangeland on a 1 percent slope at 2,025 meters elevation (colors are for dry soil unless otherwise noted).
A--0 to 15 cm; dark grayish brown (10YR 4/2) fine sandy loam; very dark brown (10YR 2/2) moist; weak very fine granular structure; very friable, soft, nonsticky and nonplastic; common very fine, fine and medium roots; finely disseminated calcium carbonate; slightly effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (7 to 16 cm thick)
Bw--15 to 40 cm; light brownish gray (2.5Y 6/2) fine sandy loam; very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; very friable, soft, nonsticky and nonplastic; common very fine roots; 5 percent gravel; finely disseminated calcium carbonate; slightly effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (15 to 32 cm thick)
Bk1--40 to 70 cm; light gray (2.5Y 7/2) loam; light olive brown (2.5Y 5/3) moist; weak fine subangular blocky structure; very friable, slightly hard, slightly sticky and nonplastic; 25 percent medium, prominent, irregular soft masses of calcium carbonate; violently effervescent, strongly alkaline (pH 8.8); gradual smooth boundary. (25 to 90 cm thick)
Bk2--70 to 117 cm; light gray (2.5Y 7/2) silt loam; light olive brown (2.5Y 5/3) moist; 20 percent fine, distinct, yellowish brown (10YR 5/6) moist, irregular mottles (masses of oxidized iron); weak fine subangular blocky structure; friable, slightly hard, slightly sticky and slightly plastic; 15 percent fine, prominent, irregular soft masses of calcium carbonate; violently effervescent, strongly alkaline (pH 8.6); gradual wavy boundary. (0 to 50 cm thick)
C--117 to 152 cm; pale yellow (2.5Y 7/3) loamy sand; light olive brown (2.5Y 5/4) moist; 15 percent fine, distinct, yellowish brown (10YR 5/6) moist, irregular mottles (masses of oxidized iron); massive; very friable, soft, nonsticky and nonplastic; finely disseminated calcium carbonate; strongly effervescent, strongly alkaline (pH 8.6).
TYPE LOCATION: Wolverine Creek topographic quadrangle; Beaverhead County, Montana; 432 meters north and 234 meters east of the SW corner of section 7, T. 14S, R. 4W; UTM 409245E, 4942212N, Datum NAD83, Zone 12.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 2 to 5 degrees C
Depth to calcic horizon - 25 to 50 cm
Mottles - relic redoximorphic features
A horizon
Value: 4 or 5 dry; 2 to 4 moist
Chroma: 2 to 4 dry; 1 or 2 moist
Texture: fine sandy loam or loam
Clay content: 10 to 20 percent
Rock fragments: 0 to 10 percent gravel
Calcium carbonate equivalent: 0 to 5 percent
Reaction: pH 7.6 to 8.0
Bw horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 3 to 5; moist
Chroma: 2 or 3; dry or moist
Texture: fine sandy loam, sandy clay loam or loam
Clay content: 15 to 25 percent
Rock fragments: 0 to 15 percent gravel
Calcium carbonate equivalent: 1 to 10 percent
Reaction: pH 7.6 to 8.2
Bk1 horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 to 7 dry; 3 to 6 moist
Chroma: 2 or 3; dry or moist
Texture: loam, fine sandy loam or sandy clay loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 10 percent gravel
Calcium carbonate equivalent: 15 to 40 percent
Sodium absorption ratio: 0 to 8
Reaction: pH 8.0 to 8.8
Bk2 horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 to 7 dry; 4 to 6 moist
Chroma: 2 to 4; dry or moist
Texture: loam, silt loam or fine sandy loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 5 percent gravel
Calcium carbonate equivalent: 15 to 40 percent
Sodium absorption ratio: 0 to 12
Reaction: pH 8.0 to 8.8
C horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 to 7 dry; 4 or 5 moist
Chroma: 2 to 4; dry or moist
Texture: loamy sand or loamy fine sand
Clay content: 5 to 12 percent
Rock fragments: 0 to 5 percent gravel
Calcium carbonate equivalent: 1 to 10 percent
Sodium absorption ratio: 0 to 12
Reaction: pH 8.0 to 8.8
COMPETING SERIES:
Kenosha (CO) - are moderately deep to a paralithic contact
Knep (ID) - are moderately deep to a paralithic contact
GEOGRAPHIC SETTING:
Landform - alluvial fans, fan remnants and lakebeds
Elevation - 2,015 to 2,130 meters
Slope - 0 to 4 percent
Parent materials - alluvium and/or lake sediments
Climate - long, cold winters; moist springs; cool summers
Mean annual precipitation - 350 to 450 millimeters
Mean annual air temperature - 1 to 4 degrees C
Frost-free period - 50 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate over rapid permeability.
USE AND VEGETATION: These soils are typically native range and used for grazing cattle and for wildlife habitat. Vegetation is chiefly three-tip sagebrush, Sandberg bluegrass, Idaho fescue, pussytoes, lupine and other forbs and grasses.
DISTRIBUTION AND EXTENT: The Lyonsbridge series is of small extent in the intermountain valleys of southwestern Montana. MLRA - 44B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Horse Prairie-South Valley Area - Part of Beaverhead County, Montana, 2011; proposed in Beaverhead County, Montana, 2010.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from the soil surface to 15 cm (A horizon)
Cambic horizon from 15 to 40 cm (Bw horizon)
Calcic horizon - from 40 to 117 cm (Bk1, Bk2 horizons)
Particle-size control section - from 25 to 100 cm (part of the Bw, Bk1, part of the Bk2 horizons)
Lyonsbridge soils have a cryic temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.