LOCATION ETTIENRIDGE             MT

Tentative Series
Ird. KTS-EMM
02/2013

ETTIENRIDGE SERIES


The Ettienridge series consists of moderately deep, well drained soils that formed in colluvium and/or slope alluvium over residuum derived from limestone. These soils occur on mountain slopes, hillslopes, canyons, and structural benches. Slopes are 2 to 70 percent. Mean annual precipitation is about 500 mm, and the mean annual temperature is about 3 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, carbonatic Ustic Calcicryepts

TYPICAL PEDON: Ettienridge very gravelly loam, in forest on a 45 percent north slope at an elevation of 1842 meters (Colors are for dry soil unless otherwise noted).

Oi--0 to 8 cm; Moss and slightly decomposed forest litter; clear smooth boundary. (2 to 10 cm thick)

A--8 to 20 cm; dark grayish brown (10YR 4/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine, medium, and coarse roots; few very fine and fine irregular pores; 40 percent gravel; slightly alkaline (pH 7.6); clear smooth boundary. (8 to 20 cm thick)

Bk1--20 to 42 cm; grayish brown (10YR 5/2) very gravelly loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, fine, medium, and coarse roots; few very fine and fine tubular pores; 50 percent gravel and 5 percent cobbles; continuous prominent calcium carbonate casts on bottoms of rock fragments and finely disseminated calcium carbonate; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary.

Bk2--42 to 74 cm; grayish brown (10YR 5/2) very gravelly loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, medium and coarse roots; few very fine and fine tubular pores; 45 percent gravel and 10 percent cobbles; continuous prominent calcium carbonate casts on bottoms of rock fragments and finely disseminated calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (combined thickness of Bk horizons - 30 to 80 cm thick)

R--74 to 152 cm; hard limestone bedrock.

TYPE LOCATION: Judith Basin County, Montana; located 110 meters north and 140 meters west of the southeast corner of sec. 24, T. 13 N., R 10 E; Ettien Spring topographic quadrangle; UTM 12T, 0546614e., 5190558n. NAD 83.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 1 to 4 degrees C.
Depth to lithic contact - 50 to 100 cm.
Depth to calcic horizon - 8 to 30 cm.
Note: When the mineral surface is mixed to a depth of 18cm, color does not meet the requirements for a mollic epipedon.

A horizon
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Clay content: 15 to 26 percent
Texture: loam or silt loam
Rock fragments: 15 to 50 percent--15 to 60 percent gravel or channers, 0 to 15 percent cobbles or flagstones
Calcium carbonate equivalent: 0 to 10 percent
Reaction: pH 7.2 to 8.2

Bk horizons
Value: 4 to 6 dry; 4 to 5 moist
Chroma: 2 to 4; dry or moist
Clay content: 16 to 25 percent
Rock fragments: 35 to 75 percent-35 to 70 percent gravel or channers, 0 to 20 percent cobbles or flagstones
Calcium carbonate equivalent: 40 to 60 percent
Reaction: pH 7.9 to 8.4

COMPETING SERIES:
Scudder (MT) - very deep
Foureyes (MT) - very deep

GEOGRAPHIC SETTING:
Landform - mountain slopes, hillslopes, canyons, and structural benches. Elevation - 1600 to 2200 meters.
Slope - 2 to 70 percent.
Parent material - colluvium and/or slope alluvium over residuum derived from limestone.
Climate - long, cold winters; moist springs; short warm summers.
Mean annual precipitation - 380 to 610 mm.
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 permeability.

USE AND VEGETATION: Ettienridge soils are used mainly for timber, wildlife and recreation. The vegetation is mainly Douglas-fir, ponderosa pine, lodgepole pine, spruce, limber pine, spirea, ninebark, common juniper, snowberry, twinflower, Oregon grape, russet buffaloberry, rose, clematis, wintergreen, arnica (species), pinegrass, elksedge and other miscellaneous grasses and forbs.

DISTRIBUTION AND EXTENT: Ettienridge soils are of limited extent in central Montana. MLRA 43B.

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

SERIES PROPOSED: Judith Basin County, Montana, 2012. Ettienridge series is named for a place on the Ettien Spring topographic quadrangle.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 20 cm (Oi and A horizons)
Calcic horizon - from 20 to 74 cm (Bk horizons)
Particle-size control section - from 25 to 74 cm (Bk horizons)

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

Taxonomic version: Eleventh Edition, 2010.


National Cooperative Soil Survey
U.S.A.