LOCATION IPASHA MT
Tentative Series
Rev. EMR-JMS-RJS
05/2017
IPASHA SERIES
The Ipasha series consists of very deep, very poorly drained soils that formed in alluvium and till derived from metasedimentary rock. Ipasha soils are commonly found along drainageways on moraines. Slopes are 0 to 15 percent. The mean annual precipitation is about 1,150 mm, and the mean annual air temperature is about 3.5 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Argic Cryaquolls
TYPICAL PEDON: Ipasha loam on 3 percent slope, at 1,715 meters elevation. (Colors are for moist soil unless otherwise noted.)
Oe--0 to 7 cm; black (10YR 2/1) moderately decomposed plant material, very dark grayish brown (10YR 3/2) dry; slightly acid (pH 6.2); clear smooth boundary.
A--7 to 26 cm; very dark brown (10YR 2/2) loam, dark grayish brown (10YR 4/2) dry; weak fine granular structure; friable, soft, slightly sticky and slightly plastic; many fine roots; many fine irregular pores; neutral (pH 6.7); clear smooth boundary.
Bt--26 to 45 cm; very dark grayish brown (10YR 3/2) loam, grayish brown (10YR 5/2) dry; weak fine subangular blocky structure; friable, slightly hard, slightly sticky and slightly plastic; few fine roots; many fine tubular pores; 20 percent clay films on surfaces along root channels; 2 percent fine brown (10YR 4/3), moist, masses of oxidized iron at top of horizon; 3 percent gravel; neutral (pH 6.8); gradual smooth boundary.
Bg--45 to 73 cm; dark gray (10YR 4/1) loam, gray (10YR 5/1) dry; weak medium subangular blocky structure; friable, slightly hard, slightly sticky and nonplastic; few fine roots; many fine tubular pores; 5 percent gravel; neutral (pH 6.8); clear smooth boundary.
Cg--73 to 150 cm; dark grayish brown (10YR 4/2) very gravelly sandy loam, light brownish gray (10YR 6/2) dry; massive; soft; friable, slightly sticky and nonplastic; 50 percent gravel; neutral (pH 6.8).
TYPE LOCATION: Glacier County, Montana; located about 625 meters north and 40 meters west of the southeast corner of sec. 23, T. 33N., R. 14W; Cut Bank Pass topographic quadrangle; UTM Zone 12, 323774e, 5385932n. NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 2.5 to 6.5 degrees C
Mollic epipedon thickness: 25 to 55 cm
Depth to argillic horizon: 20 to 42 cm
Particle-size control section: averages 18 to 34 percent clay
Depth to a seasonally high water table: 0 to 15 cm
Note: Some pedons have a thin Oi horizon. Also, some pedons may have a thin volcanic ash layer in the upper part of the mineral layer.
O horizons
Thickness: 3 to 9 cm
A horizon
Hue: 10YR or 2.5Y dry or moist
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 2 or 3 dry or moist
Texture (less than 2 mm fraction): loam, mucky loam
Clay content: 15 to 26 percent
Rock fragments: 0 to 10 percent--0 to 10 percent gravel; 0 to 5 percent cobbles
Reaction: pH 6.2 to 6.8
Thickness: 11 to 35 cm
Bt horizon
Hue: 7.5YR, 10YR, or 2.5Y dry or moist
Value: 4 to 6 dry; 3 to 5 moist
Chroma: 1 to 3 dry or moist
Texture (less than 2 mm fraction): loam, clay loam, silt loam, silty clay loam
Clay content: 20 to 34 percent
Rock fragments: 0 to 10 percent--0 to 10 percent gravel; 0 to 5 percent cobbles
Reaction: pH 6.4 to 7.2
Thickness: 16 to 50 cm
Bg horizon
Hue: 10YR or 7.5YR dry or moist
Value: 5 to 7 dry; 4 to 6 moist
Chroma: 1 or 2 dry or moist
Texture (less than 2 mm fraction): loam, silt loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 25 percent--0 to 25 percent gravel; 0 to 5 percent cobbles
Reaction: pH 6.4 to 7.2
Thickness: 0 to 28 cm
Cg horizon
Hue: 7.5YR, 10YR or 2.5Y dry or moist
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 1 or 2 dry or moist
Texture: loam, fine sandy loam, sandy loam
Clay content: 10 to 27 percent
Rock fragments: 50 to 75 percent--35 to 75 percent gravel; 0 to 15 percent cobbles; 0 to 5 percent stones
Reaction: pH 6.2 to 7.2
COMPETING SERIES: No competing series exist.
GEOGRAPHIC SETTING:
Landform: along drainageways on moraines
Elevation: 1,100 to 2,000 meters
Slope: 0 to 15 percent
Parent material: alluvium and till derived from metasedimentary rock
Climate: long, cold winters; moist springs; short warm summers with May and June receiving the most precipitation
Mean annual precipitation: 900 to 1,600 mm
Mean annual air temperature: 1.5 to 6.0 degrees C.
Frost-free period: 35 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Very poorly drained and 1.5 to 15 um/sec.
USE AND VEGETATION: These soils are used mainly for wildlife. These areas are dominated by tall willows, including Drummond's and Bebb's willows, alderleaf buckthorn, bluejoint reedgrass, and field horsetail.
DISTRIBUTION AND EXTENT: Ipasha soils are of limited extent in northern Montana. MLRAs 43A and 43B.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Glacier County, Montana. This soil is named for a peak in Glacier National Park.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 7 to 45 cm (A, Bt horizons)
Argillic horizon: 26 to 45 cm (Bt horizon)
Reduced matrix: 45 to 152 cm (Bt, Bg, Cg horizons)
Particle-size control section: from 26 to 45 cm (Bt horizon)
Ipasha soils have a cryic temperature regime and an aquic moisture regime.
Taxonomic version: Keys to Soil Taxonomy, Twelfth Edition, 2014.
National Cooperative Soil Survey
U.S.A.