LOCATION EUELL                   MT

Established Series
JMS/KTS/RJS
04/2011

EUELL SERIES

The Euell series consists of deep, well drained soils that formed in colluvium over residuum derived from rhyolite, rhyodacite, or rhyolitic tuff. These soils are on mountain slopes, hills, benches and ridges. Slopes are 4 to 60 percent. Mean annual precipitation is about 430 millimeters and mean annual air temperature is about 3 degrees C.

TAXONOMIC CLASS: Ashy-Skeletal, glassy Vitrandic Argicryolls

TYPICAL PEDON: Euell gravelly ashy loam, in rangeland on a 28 percent slope at 1,890 meters elevation (colors are for dry soil unless otherwise indicated).

A--0 to 25 cm; dark grayish brown (10YR 4/2) gravelly ashy loam, very dark brown (10YR 2/2) moist; weak fine granular structure; very friable, soft, slightly sticky and slightly plastic; many very fine and fine, and common medium roots; many fine irregular pores; 20 percent gravel, 5 percent cobbles, 5 percent stones; moderately acid (pH 5.8); clear smooth boundary. (18 to 30 cm thick)

Bt--25 to 79 cm; brown (10YR 5/3) extremely gravelly ashy sandy clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; friable, slightly hard, slightly sticky and moderately plastic; common very fine and fine, and few medium roots; common very fine tubular pores; common faint discontinuous clay films on ped faces and along pore linings; 55 percent gravel, 5 percent cobbles, 5 percent stones; neutral (pH 6.8); gradual smooth boundary. (15 to 70 cm thick)

BC--79 to 109 cm; light olive brown (2.5Y 5/3) very gravelly ashy sandy loam, olive brown (2.5Y 4/3) moist; weak medium subangular blocky structure; friable, slightly hard, slightly sticky and slightly plastic; few very fine and fine roots; common very fine and few fine tubular pores; 45 percent gravel, 5 percent cobbles, 5 percent stones; neutral (pH 7.0); abrupt smooth boundary.

R--109 cm; indurated tuffaceous rhyolite.

TYPE LOCATION: Ramsay topographic quadrangle, Silver Bow County, Montana; 530 meters north and 80 meters west of the SE corner of section 35, T. 4 N., R. 9 W. UTM Zone 12: 370458e, 5101201n, NAD 83.

RANGE IN CHARACTERISTICS:
Soil temperature - 2 to 6 degrees C
Thickness of mollic epipedon - 18 to 30 cm
Depth to top of argillic horizon - 18 to 30 cm
Depth to a lithic contact - 100 to 150 cm
Volcanic glass - 30 to 50 percent in the coarse silt and sand fraction.
Acid oxalate Al + 1/2 Fe - .12 to .20 percent

A horizon
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Texture: ashy loam or ashy sandy loam
Clay content: 10 to 27 percent
Rock fragments: 5 to 55 percent--10 to 45 percent gravel, 0 to 30 percent cobbles, 0 to 5 percent stones
Reaction: pH 5.6 to 7.8

Bt horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 4 to 6 dry; 4 or 5 moist
Chroma: 2 to 4; dry or moist
Texture: ashy sandy clay loam, ashy clay loam, ashy sandy loam or ashy loam
Clay content: 16 to 32 percent
Rock fragments: 35 to 70 percent--20 to 70 percent gravel, 0 to 25 percent cobbles, 0 to 5 percent stones
Reaction: pH 6.0 to 8.0

BC horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 to 7 dry; 4 or 5 moist
Chroma: 3 or 4; dry or moist
Texture: ashy sandy loam, ashy sandy clay loam or ashy loam
Clay content: 10 to 25 percent
Rock fragments: 30 to 75 percent--25 to 45 percent gravel, 0 to 30 percent cobbles, 0 to 5 percent stones
Reaction: pH 6.0 to 8.0

COMPETING SERIES:
Ashflat (CA) - is very deep
Beechcreek (MT) - is moderately deep to a lithic contact
Boulderfan (CA) - is very deep
Cowbell (CA) - is very deep
Fendersflat (CA) - have a xeric soil moisture regime
Hardshoulder (CA) - is very deep
Paynepeak (CA) - have a xeric soil moisture regime
Pyropatti (CA) - have a xeric soil moisture regime
Snag (NV) - is very deep
Tusune (NV) - is moderately deep to a paralithic contact

GEOGRAPHIC SETTING:
Landform - mountain slopes, hills, benches and ridges
Elevation - 1,555 to 2,275 meters
Slope - 4 to 60 percent
Parent material - colluvium over residuum derived from rhyolite, rhyodacite, or rhyolitic tuff
Climate - long, cold winters; cold, moist springs; short, cool summers
Mean annual precipitation - 300 to 585 millimeters, much of which falls as snow and as spring rain
Mean annual air temperature - 1 to 6 degrees centigrade
Frost-free period - 30 to 70 days

GEOGRAPHICALLY ASSOCIATED SOILS: Associated soils which occur on similar landforms are the Nissler, Hungryhill and Eastridge soil series. Nissler soils are very deep. Hungryhill soils are moderately deep to a lithic contact. Eastridge soils are very deep.

DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.

USE AND VEGETATION: Euell soils are used mainly for rangeland. Potential native vegetation is chiefly mixed grasses, such as bluebunch wheatgrass, rough fescue and Idaho fescue with some areas of widely scattered Douglas fir.

DISTRIBUTION AND EXTENT: Euell soils are of small extent in southwestern and central Montana. MLRA - 43B.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.

SERIES ESTABLISHED: Silver Bow County, Montana, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 25 cm (A horizon)
Argillic horizon - from 25 to 79 cm (Bt horizon)
Lithic contact - at 109 cm (R horizon)
Particle-size control section - from 25 to 75 cm (Bt horizon)

Euell soils have a cryic temperature regime and an ustic moisture regime.

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National Cooperative Soil Survey
U.S.A.