LOCATION CRITTENDEN              MT

Established Series
Rev. JAL/SJJ
04/2016

CRITTENDEN SERIES


The Crittenden series consists of deep, well drained soils formed in material weathered from granite rock. Crittenden soils are on hills. Slopes are 2 to 35 percent. The mean annual precipitation is about 12 inches, and the mean annual air temperature is about 43 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Aridic Argiustolls

TYPICAL PEDON: Crittenden sandy loam, native grassland (colors are for dry soil unless otherwise noted).

A--0 to 5 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; moderate very thin platy structure parting to moderate very fine granular; soft, very friable, slightly sticky and nonplastic; many very fine roots; 5 percent angular pebbles; slightly acid (pH 6.2); clear smooth boundary. (4 to 6 inches thick)

Bt--5 to 20 inches; pale brown (10YR 6/3) clay loam, brown (10YR 4/3) moist; moderate medium prismatic structure; slightly hard, friable, moderately sticky and slightly plastic; common very fine roots; many very fine tubular and interstitial pores; many distinct dark brown (10YR 3/3) moist, clay films on faces of peds; clay bridges between sand grains; 5 percent angular pebbles; slightly alkaline (pH 7.4); clear smooth boundary. (6 to 12 inches thick)

Bk1--20 to 31 inches; light gray (2.5Y 7/2) gravelly sandy loam, grayish brown (2.5Y 5/2) moist; weak medium prismatic structure; slightly hard, friable, moderately sticky and slightly plastic; common very fine roots; many very fine tubular and interstitial pores; 20 percent angular pebbles; common fine and medium masses of lime; continuous distinct lime coatings on undersides of pebbles; violently effervescent; moderately alkaline (pH 8.4); gradual smooth boundary. (5 to 15 inches thick)

2Bk2--31 to 50 inches; reddish yellow (7.5YR 6/6) very gravelly loamy coarse sand, brown (7.5YR 5/4) moist; massive; loose, slightly sticky and nonplastic; few very fine roots; 50 percent angular pebbles; common fine masses of lime; continuous distinct lime coatings on underside of pebbles; strongly effervescent; moderately alkaline (pH 8.2); gradual smooth boundary. (15 to 25 inches thick)

R--50 inches; hard granitic rock with a few cracks.

TYPE LOCATION: Lewis and Clark County, Montana; 650 feet north and 200 feet east of the SW corner of sec. 35, T. 11 N., R. 4 W.

RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Depth to Bk horizon - 10 to 18 inches.
Depth to sandy-skeletal 2Bk2 horizon - 20 to 40 inches.
Depth to R horizon - 40 to 60 inches.

A horizon - Value: 4 or 5 dry, 3 moist
Chroma: 2 or 3
Clay content: 10 to 20 percent
Rock fragments: 0 to 15 percent angular pebbles
Reaction: pH 6.1 to 7.3

Bt horizon - Value: 5 or 6 dry, 4 moist
Chroma: 3 or 4
Texture: sandy clay loam or clay loam
Clay content: 20 to 30 percent
Rock fragments: 0 to 15 percent angular pebbles
Reaction: pH 6.6 to 7.8

Bk1 horizon - Hue: 10YR or 2.5Y
Value: 6, 7, or 8 dry; 5 or 6 moist
Chroma: 2 or 3
Texture: sandy loam or loam
Clay content: 10 to 20 percent
Rock fragments: 10 to 30 percent
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.4

2Bk2 horizon - Hue: 10YR, 7.5YR, 5Y, or 2.5Y
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 2, 3, 4, 5, or 6
Texture: loamy coarse sand or coarse sand
Clay content: 0 to 5 percent
Rock fragments: 35 to 60 percent angular pebbles
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.4 to 8.4

COMPETING SERIES:
Assinniboine (MT) - very deep.
Beavwan (MT) - very deep.
Berlake (CO) - very deep.
Bostwick (CO) - very deep.
Cheesman (CO) - moderately deep to a paralithic contact.
Duffson (CO) - moderately deep to a lithic contact.
Eapa (SD) - very deep.
Evanot (CO) - very deep.
Evanston (WY) - very deep.
Jarre (CO) - very deep.
Joplin (MT) - very deep.
Kenilworth (MT) - very deep.
Kevin (MT) - very deep.
Marmarth (ND) - moderately deep to a paralithic contact.
Nuley (MT) - has a calcic horizon.
Perrypark (CO) - very deep.
Peyton (CO) - very deep.
Reicess (WY) - very deep.
Sugakool (WY) - very deep.
Telstad (MT) - very deep.
Turret (CO) - very deep.
Udecide (MT) - moderately deep to a paralithic contact.

GEOGRAPHIC SETTING:
Landform - hills.
Elevation - 3,800 to 4,500 feet.
Slope - 2 to 35 percent.
Parent material - material weathered from granitic rock.
Climate - long, cold winters; moist springs; and warm summers.
Mean annual precipitation - 10 to 14 inches, most of which falls during the spring and early summer.
Mean annual temperature - 40 to 45 degrees F.
Frost-free period - 105 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS:

DRAINAGE AND PERMEABILITY: Well drained; moderate permeability in the upper part of the soil through the Bt horizon and rapid in the sandy-skeletal horizon.

USE AND VEGETATION: Crittenden soils are used mainly for rangeland. Potential native vegetation is mainly bluebunch wheatgrass, prairie junegrass, needleandthread, western wheatgrass, fringed sagewort, broom snakeweed, Sandberg bluegrass, juniper, and some widely spaced ponderosa pine.

DISTRIBUTION AND EXTENT: Southwestern Montana. Crittenden soils are inextensive.

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

SERIES ESTABLISHED: Lewis and Clark County Area, Montana, 1991; proposed in Lewis and Clark County, Montana, 1979.

REMARKS: Soil interpretation records: MT0373, MT0920. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 7 inches mixed (A horizon); an argillic horizon from 5 to 20 inches which is the particle-size control section (Bt horizon); a sandy skeletal 2Bk2 horizon; and a lithic contact (R) at a depth of 50 inches. Crittenden soils have a frigid temperature regime and an ustic moisture regime that borders on aridic.


National Cooperative Soil Survey
U.S.A.