LOCATION CHARGOLD MT
Established Series
Rev. JMS/EMR/RJS
07/2013
CHARGOLD SERIES
The Chargold series consists of very deep, poorly drained soils formed in alluvium derived from volcanic ash and mixed sources. These soils are in backswamps on floodplains. Slopes are 0 to 2 percent. The average annual precipitation is about 356 mm, and the average annual temperature is about 6 degrees C.
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Aquandic Endoaquolls
TYPICAL PEDON: Chargold mucky silt loam, on a 1 percent slope at an elevation of 1,126 meters, in drained hayland. (Colors are for moist soil unless otherwise stated.)
Oe--0 to 6 cm; moderately decomposed plant material from dead roots and stems of grass and grass-like plants; abrupt smooth boundary.
A--6 to 32 cm; black (10YR 2/1) mucky silt loam; very dark very dark gray (10YR 3/1) dry; moderate medium angular blocky structure; very firm, very hard, very sticky and very plastic; many very fine and few fine roots; few very fine tubular pores; slightly acid (pH 6.1); abrupt smooth boundary. (25 to 35 cm thick)
C--32 to 39 cm; dark gray (10YR 4/1) ashy very fine sandy loam; gray (10YR 5/1) dry; massive; friable, slightly hard, moderately sticky, slightly plastic; common very fine and few fine roots; common very fine interstitial pores; neutral (pH 6.9); abrupt smooth boundary. (7 to 25 cm thick)
Ab--39 to 57 cm; black (10YR 2/1) silt loam; very dark gray (10YR 3/1) dry; moderate fine angular blocky structure; friable, slightly hard, moderately sticky and moderately plastic; common very fine, fine, and medium roots; common very fine and fine irregular pores; neutral (pH 6.9); abrupt smooth boundary. (0 to 18 cm thick)
C'--57 to 76 cm; dark gray (10YR 4/1) ashy very fine sandy loam, gray (10YR 5/1) dry; massive; friable, slightly hard, slightly sticky, nonplastic; many very fine roots; common very fine interstitial pores; neutral (pH 6.9); abrupt smooth boundary. (19 to 42 cm thick)
A'b--76 to 110 cm; very dark brown (10YR 2/2) silt loam; very dark grayish brown (10YR 3/2) dry; moderate medium angular blocky structure; friable, slightly hard, moderately sticky and moderately plastic; 10 percent fine distinct yellowish brown (10YR 5/6) redox concentrations; few very fine and fine roots; common very fine irregular pores; slightly acid (pH 6.5); abrupt smooth boundary. (0 to 34 cm thick)
2Cg--110 to 165 cm; greenish gray (10Y 5/1) coarse sandy loam, light greenish gray (10Y 7/1) dry; massive; friable, slightly hard, slightly sticky and nonplastic; 10 percent fine distinct yellowish brown (10YR 5/6) redox concentrations; 2 percent gravels; few fine roots; common fine interstitial pores; neutral (pH 7.2).
TYPE LOCATION: Hamilton South topographic quadrangle, Ravalli County, Montana; 817 meters west and 175 meters north of the SE corner of sec. 23, T. 5 N., R. 21 W; UTM zone 11, 717150.57E, 5116612.9N, NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 8 degrees C
Mollic epipedon thickness - 25 to 35 cm
Depth to seasonal high water table - 30 to 45 cm
Depth to redox features - 35 to 76 cm
Depth to strong gleying - 108 to 120 cm
Particle-size control section - 31 to 100 cm
It is assumed that enough active ferrous iron occurs in the A and upper C horizons, when aquic conditions are present, to give positive reactions to alpha, alpha-dipyridyl.
A horizon
Chroma: 1 or 2 moist or dry
Texture: mucky silt loam or mucky silty clay loam
Clay content: 20 to 30 percent
Reaction: pH 5.5 to 6.5
C horizons
Value: 4 or 5 moist or dry
Chroma: 1 or 2 moist or dry
Textures: ashy very fine sandy loam or ashy silt loam
Clay content: 5 to 15 percent
Reaction: pH 6.0 to 7.4
Ab horizons (where present)
Chroma: 1 or 2 moist or dry
Texture: silt loam or silty clay loam
Clay content: 20 to 28 percent
Reaction: pH 6.0 to 7.4
2Cg horizon
Textures: coarse sandy loam, sandy loam, or loamy coarse sand
Clay content: 5 to 15 percent
Rock fragments: 0 to 10 percent gravel
Reaction: pH 6.0 to 7.4
COMPETING SERIES:
Esro (CA) - have redox features from 25 to 200 cm; have strong gleying at 56 cm
Odenson (ID) - have horizons of secondary carbonate accumulation; have strong gleying and redox features from 23 to 165 cm; have a lithologic discontinuity at depths of 18 to 25 cm
GEOGRAPHIC SETTING:
Landform: backswamps on flood plains
Elevation: 1,067 to 1,445 meters
Slope: 0 to 2 percent
Parent material: alluvium
Climate: long, cold winters; moist springs; warm summers
Mean annual precipitation: 305 to 380 mm
Mean annual air temperature: 4 to 7 degrees C.
Frost-free season: 90 to 115 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Poorly drained; moderate to moderately rapid permeability. Drained phases are recognized.
USE AND VEGETATION: Used mainly for irrigated hayland and pasture (when artificially drained), and wildlife habitat. Vegetation is mainly creeping meadow foxtail, orchard grass, mountain rush, and Nebraska sedge.
DISTRIBUTION AND EXTENT: Chargold soils are of small extent in intermountain valleys of western Montana. MLRA 44A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Bitterroot Valley Area, Montana, 2013; proposed in Ravalli County, Montana, 2009.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 6 to 32 cm (A horizon)
Redox concentrations - from 76 to 165 cm (A'b and 2Cg horizons)
Aquandic feature - from 57 to 76 cm (C' horizon)
Horizon of strong gleying - from 110 to 165 cm (2Cg horizon)
Lithologic discontinuity - at 110 cm (2Cg horizon)
Particle-size control section - from 31 to 106 cm (part of the A, C, Ab, C', and part of the A'b horizons)
Chargold soils have a frigid temperature regime and an aquic moisture regime.
National Cooperative Soil Survey
U.S.A.