LOCATION DUCKCREEK MT
Established Series
Rev. DRS-JAL-EMM
07/2012
DUCKCREEK SERIES
The Duckcreek series consists of moderately deep, well drained soils that formed in interbedded shale and sandstone residuum and clayey sedimentary beds. These soils are on hills, mountains and escarpments. Slopes are 4 to 60 percent. Mean annual precipitation is about 21 inches and mean annual temperature is about 39 degrees F.
TAXONOMIC CLASS: Fine, mixed, superactive Ustic Argicryolls
TYPICAL PEDON: Duckcreek loam, in rangeland (Colors are for dry soil unless otherwise noted).
A--0 to 6 inches; brown (10YR 4/3) loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and few fine and medium roots; many very fine and fine pores; 5 percent gravel, 5 percent stones; neutral (pH 7.2); clear smooth boundary. (5 to 12 inches thick)
Bt1--6 to 15 inches; dark yellowish brown (10YR 4/4) clay loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure parting to strong fine granular; hard, friable, moderately sticky and moderately plastic; common very fine and few fine and medium roots; common very fine pores; common faint discontinuous clay films on faces of peds; 10 percent gravel; neutral (pH 7.2); clear smooth boundary.
Bt2--15 to 29 inches; light yellowish brown (10YR 6/4) gravelly clay loam, brown (10YR 5/3) moist; weak medium subangular blocky structure parting to moderate fine granular; hard, friable, moderately sticky and moderately plastic; few very fine and fine roots; common very fine interstitial and tubular pores; common faint discontinuous clay films on faces of peds; 20 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary. (Combined thickness of the Bt1 and Bt2 horizon 15 to 25 inches)
Bk--29 to 36 inches; light gray (2.5Y 7/2) sandy clay loam, grayish brown (2.5Y 5/2) moist; weak coarse prismatic structure; soft, very friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine interstitial and tubular pores; common fine soft masses of lime; 30 percent soft shale fragments; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (5 to 17 inches thick)
Cr--36 to 60 inches; semiconsolidated black shale; strongly effervescent.
TYPE LOCATION: Sweet Grass County, Montana; 200 feet east and 2400 feet south of the northwest corner of section 19, T.2 N., R.12 E.; Latitude 45 degrees, 54 minutes, 31 seconds N., Longitude 110 degrees, 17 minutes, 28 seconds W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 36 to 40 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 8 to 15 inches.
Depth to Bk horizon - 15 to 35 inches.
Depth to Cr horizon - 20 to 40 inches.
A horizon - Hue: 10YR or 2.5Y
Value: 3, 4, or 5 dry; 2 or 3 moist
Chroma: 1, 2, or 3
Texture: loam or clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 25 percent-- 0 to 5 percent flagstones or stones, 0 to 10 percent cobbles, 0 to 15 percent channers or gravel; 0 to 20 percent soft shale chips.
Reaction: pH 5.6 to 7.4
Bt1 horizon - Hue: 10YR or 2.5Y
Value: 4, 5 or 6 dry; 3, 4 or 5 moist
Chroma: 2, 3 or 4
Texture: clay loam or clay
Clay content: 35 to 50 percent
Rock fragments: 0 to 25 percent-- 0 to 5 percent cobbles, 0 to 20 percent channers or gravel; 0 to 20 percent soft shale chips.
Reaction: pH 5.6 to 7.3
Bt2 horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3 or 4
Texture: clay loam or clay
Clay content: 35 to 50 percent
Rock fragments: 0 to 35 percent -- 0 to 5 percent cobbles, 0 to 30 percent channers or gravel; 0 to 20 percent soft shale chips.
Reaction: pH 6.1 to 7.8
Bk horizon - Hue: 10YR or 2.5Y
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 2, 3, or 4
Texture: loam, clay loam or clay
Clay content: 27 to 45 percent
Rock fragments: 0 to 35 percent--0 to 5 percent cobbles, 0 to 30 percent channers or gravel; 10 to 35 percent soft shale chips.
Calcium Carbonate equivalent: 5 to 15 percent
Reaction: pH 7.4 to 8.4
COMPETING SERIES:
Bangtail (MT) - does not have horizons of secondary calcium carbonate accumulation.
Bridger (MT) - does not have a paralithic contact above 60 inches.
Echard (UT) - does not have a paralithic contact above 60 inches; formed in soft rhyolitic tuff or strongly cemented ash.
Melville (MT) - does not have a paralithic contact above 60 inches.
Mollet (MT) - does not have a paralithic contact above 60 inches; does not have horizons of secondary calcium carbonate accumulation.
Rattler (MT) - does not have a paralithic contact above 60 inches.
Sevier (UT) - has Bt horizon which is 4 to 10 inches thick; is moderately well drained; does not have horizons of secondary calcium carbonate accumulation.
GEOGRAPHIC SETTING:
Landform - hills, mountains, escarpments.
Elevation - 5,600 to 8,300 feet.
Slope - 4 to 60 percent.
Parent material - residuum derived from cretaceous interbedded shale and sandstone.
Climate - long, cold winters; cool, moist springs; short summers.
Mean annual precipitation - 19 to 25 inches.
Mean annual air temperature - 35 to 43 degrees F.
Frost-free period - 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: Duckcreek soils are used mainly for rangeland and wildlife habitat. Potential native vegetation may include Idaho fescue, Richardson needlegrass, Columbia needlegrass, mountain brome, lupine, and sticky geranium.
DISTRIBUTION AND EXTENT: Duckcreek soils are of small extent in south central Montana. MLRAs 43B and 46.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Sweet Grass County, Montana, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from the surface to 15 inches (A and Bt1 horizons)
Argillic horizon - from 6 to 29 inches (Bt1 and Bt2 horizons)
Horizon of secondary calcium carbonate accumulation - from 29 to 36 inches (Bk horizon)
Paralithic contact - interbedded soft shale and sandstone from 36 to 60 inches (Cr horizon)
Duckcreek soils have a cryic temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.