LOCATION CRACKERVILLE            MT

Established Series
Rev. TJK-DES-EMM
07/2012

CRACKERVILLE SERIES

The Crackerville series consists of moderately deep, well drained soils that formed in slope alluvium, residuum and colluvium derived from granitic and other coarse grained igneous rocks. These soils are on bedrock-floored plains, mountains, escarpments, ridges and hills. Slopes are 2 to 80 percent. Mean annual precipitation is about 17 inches, and mean annual temperature is about 40 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Argiustolls

TYPICAL PEDON: Crackerville loam, bouldery in rangeland (colors are for dry soil unless otherwise noted).

A--0 to 7 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; many very fine and common fine interstitial pores; 10 percent gravel; slightly acid (pH 6.2); clear smooth boundary. (6 to 15 inches)

Bt--7 to 15 inches; yellowish brown (10YR 5/4) very gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium and coarse prismatic structure parting to moderate medium and coarse subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine and few fine roots; common very fine and fine pores; common faint clay films on faces of peds and bridging sand grains; 40 percent gravel; neutral (pH 7.2); clear wavy boundary. (4 to 17 inches thick)

BC--15 to 23 inches; pale brown (10YR 6/3) gravelly coarse sandy loam, brown (10YR 4/3) moist; weak coarse prismatic structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and few fine roots; common very fine and few fine pores; 30 percent gravel; neutral (pH 7.2); clear wavy boundary. (0 to 10 inches thick)

Cr--23 to 31 inches; very pale brown (10YR 7/3) decomposed granite bedrock (grus) which crushes to very gravelly loamy coarse sand or coarse loamy sand. (3 to 18 inches thick)

R--31 inches; hard granite bedrock.

TYPE LOCATION: Jefferson County, Montana; 600 feet south and 800 feet east of the NW corner of sec. 16, T. 5 N., R. 2 W.

RANGE IN CHARACTERISTICS:

Soil temperature - 38 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 15 inches.
Depth to argillic horizon - 7 to 15 inches.
Depth to Cr horizon - 20 to 38 inches.
Depth to bedrock - 23 to 40 inches.

A horizon
Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Texture: sandy loam, loam, coarse sandy loam or sandy clay loam
Clay content: 14 to 27 percent
Rock fragments: 0 to 50 percent--0 to 20 percent stones and boulders; 0 to 10 percent cobbles; 5 to 40 percent gravel (gravel are mainly less than 7mm in diameter)
Reaction: pH 5.1 to 7.3

Bt horizon
Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 3, 4 or 5 moist
Chroma: 3, 4, or 6
Texture: loam, clay loam or sandy clay loam
Clay content: 20 to 30 percent
Rock fragments: 35 to 60 percent--0 to 15 percent cobbles; 35 to 45 percent gravel (gravel are mainly less than 7mm in diameter)
Reaction: pH 6.1 to 7.8

BC horizon
Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3, 4, or 6
Texture: sandy loam, coarse sandy loam, or loamy coarse sand
Clay content: 5 to 20 percent
Rock fragments: 30 to 70 percent--0 to 15 percent cobbles; 30 to 55 percent gravel (gravel are mainly less than 7mm in diameter)
Reaction: pH 6.6 to 7.8

Cr horizon - Reaction: pH 6.6 to 7.3

COMPETING SERIES:

Averett (UT) - does not have a lithic contact above 60 inches.

Bendire (CO) - has a moisture control section which is dry in some part from mid- May through mid-July and is dry in all parts from mid-July through September; minimum thickness of the argillic horizon is 17 inches; does not have a Cr horizon above the andesite bedrock.

Blaincreek (MT) - has less than 45 percent sand and has textures of loam or clay loam in the fine earth fraction of the particle-size control section; does not have a Cr horizon above the lithic contact.

Borpark (CO) - does not have a lithic contact above a depth of 40 inches.

Crampton (MT) - does not have a lithic contact above a depth of 40 inches.

Curecanti (CO) - does not have a lithic contact above a depth of 40 inches.

Ess (AZ) does not have a lithic contact above a depth of 40 inches.

Hilger (MT) - does not have a lithic contact above a depth of 40 inches.

Holter (MT) - does not have a lithic contact above a depth of 40 inches.

Quincreek (MT) - does not have a paralithic contact above the lithic contact; has horizons of secondary carbonate accumulation.

Sawbuck (MT) - does not have a paralithic or lithic contact above a depth of 40 inches.

Sawicki (MT) - does not have a paralithic or lithic contact.

Shawmut (MT) - does not have a lithic contact above a depth of 40 inches.

Wickes (MT) - does not have a paralithic contact above the lithic contact; has horizon of secondary carbonate accumulation.

GEOGRAPHIC SETTING:

Landform - bedrock-floored plains, mountains, escarpments, ridges and hills.
Elevation - 3,500 to 6,600 feet.
Slope - 2 to 80 percent.
Parent material - residuum, slope alluvium and colluvium derived from granitic and other coarse grained igneous rocks.
Climate - long, cold winters; moist springs; warm, dry summers.
Mean annual precipitation - 15 to 19 inches.
Mean annual air temperature - 36 to 45 degrees F.
Frost-free period - 70 to 105 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bielenberg, Catgulch, and Connieo soils. Bielenberg soils are fine-loamy and in more concave or linear positions.
Catgulch soils do not have argillic horizons, have a lithic contact at 10 to 20 inches and are in more convex positions. Connieo soils are loamy, have a lithic contact at 10 to 20 inches, and are in more convex positions.

DRAINAGE AND PERMEABILITY: Well drained; moderate permeability in the argillic horizon and moderately rapid below.

USE AND VEGETATION: Crackerville soils are used mainly for rangeland. The potential native vegetation is rough fescue, Idaho fescue, bluebunch wheatgrass, western yarrow, wild buckwheat, rubber rabbitbrush, prairie junegrass, and wild rose.

DISTRIBUTION AND EXTENT: Crackerville soils are of small extent in southwestern Montana. MLRA 43B and 44B.

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

SERIES ESTABLISHED: Powell County, Montana, 1995; proposed Jefferson County, Montana, 1993.

REMARKS: Soil interpretation record: MT1260.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from the soil surface to 7 inches (A horizon);
Argillic horizon - from 7 to 15 inches (Bt horizon);
Particle-size control section - from 7 to 15 inches (Bt horizon);
Paralithic contact - a layer of decomposed granite bedrock (grus) from 23 to 31 inches (Cr horizon);
Lithic contact - hard granite bedrock at 31 inches (R horizon).

Crackerville soils have a frigid temperature regime and an ustic moisture regime.

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National Cooperative Soil Survey
U.S.A.