LOCATION ABSAROOK MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Argiustolls
TYPICAL PEDON: Absarook loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 5 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium and fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine and very fine roots; 5 percent pebbles; slightly acid (pH 6.2); clear wavy boundary. (4 to 6 inches thick)
Bt1--5 to 13 inches; dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium prismatic structure parting to strong fine angular blocky; hard, firm, sticky and plastic; many fine and very fine roots; many fine and very fine tubular pores; common distinct dark grayish brown (10YR 4/2) clay films on ped and gravel surfaces; 5 percent pebbles; slightly acid (pH 6.4); gradual wavy boundary.
Bt2--13 to 25 inches; dark grayish brown (10YR 4/2) clay loam, brown (10YR 4/3) moist; moderate coarse prismatic structure; hard, friable, sticky and plastic; common fine and many very fine roots; common fine and very fine tubular pores; distinct dark grayish brown clay films on ped and gravel surfaces; 10 percent pebbles; slightly acid (pH 6.4); gradual wavy boundary. (Combined thickness of Bt horizons is 8 to 20 inches.)
Bk--25 to 32 inches; light gray (10YR 7/2) clay loam, light brownish gray (10YR 6/2) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine and common very fine roots; common very fine tubular pores; 10 percent pebbles; disseminated lime with few fine masses of lime, many distinct lime casts on pebbles; strongly effervescent; moderately alkaline (pH 8.2). (6 to 18 inches thick)
R--32 inches; very dark grayish brown (10YR 3/2) hard fractured sandstone.
TYPE LOCATION: Jefferson county, Montana; 800 feet south and 2,000 feet west of the NE corner of sec. 18, T. 1 N., R. 1 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 38 to 45 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 15 inches.
Depth to argillic horizon - 4 to 9 inches.
Depth to the Bk horizon - 12 to 25 inches.
Calcium carbonate equivalent of Bk horizon - 15 to 40 percent.
Depth to bedrock - 20 to 40 inches.
A thin (less than 4 inches) C or Cr transition horizon is allowed.
A horizon - Hue: 10YR or 2.5Y
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 2 or 3
Clay content: 20 to 27 percent
Rock fragments: 0 to 30 percent pebbles
Reaction: pH 6.1 to 7.3
Bt horizons - Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 3, 4, or 5 moist
Chroma: 2, 3, or 4
Texture: loam, clay loam, sandy clay loam or silty clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 25 percent pebbles
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: 1, 2, 3, or 4
Texture: sandy loam, loam, or clay loam
Clay content: 15 to 30 percent
Rock fragments: 10 to 35 percent--0 to 5 percent cobbles, 10 to 30 percent pebbles or channers
Calcium carbonate equivalent: 15 to 40 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Beartooth (MT) - does not have a lithic contact above a depth of 60 inches.
Beeno (WY) - has a paralithic contact at depths of 20 to 40 inches.
Beilenberg (MT) - does not have lime above a depth of 40 inches; does not have a lithic contact above a depth of 60 inches.
Bookcliff (UT) - does not have a lithic contact above a depth of 60 inches.
Bullflat (SD) - does not have a lithic contact above a depth of 60 inches.
Burtoner (MT) - has a paralithic contact above the lithic contact; does not have horizon of secondary carbonate accumulation.
Clancy (MT) - does not have horizon of secondary carbonate accumulation; has a paralithic contact at depths of 20 to 40 inches.
Clasoil (MT) - does not have a paralithic contact at depths of 20 to 40 inches; does not have a calcic horizon; does not have a horizon of secondary calcium carbonate accumulation.
Cortyzack (CO) - does not have a lithic contact above a depth of 60 inches.
Dooley (MT) - has substratum of glacial till that has a bulk density of 1.55 and greater.
Empedrado (CO) - does not have a lithic contact above a depth of 60 inches.
Fairfield (MT) - does not have a lithic contact above a depth of 60 inches.
Farnuf (MT) - does not have a lithic contact above a depth of 60 inches.
Felor (SD) - does not have a lithic contact above a depth of 60 inches.
Greenway (SD) - does not have a lithic contact above a depth of 60 inches.
Gurney (SD) - has hues yellower than 7.5YR; does not have a calcic horizon.
Hangdo (UT) - does not have lime above a depth of 40 inches; does not have a lithic contact above a depth of 60 inches.
Hoppers (MT) - does not have horizon of secondary carbonate accumulation.
Hyalite (MT) - has a discontinuity of sandy-skeletal material above 40 inches and immediately below the argillic horizon; does not have a lithic contact above a depth of 60 inches.
Jeffcity (MT) - has a paralithic contact at depths of 20 to 40 inches.
Lefor (ND) - has a paralithic contact at depths of 20 to 40 inches.
Lininger (CO) - has a paralithic contact at depths of 20 to 40 inches.
Livona (ND) - does not have a lithic contact above a depth of 60 inches.
Martinsdale (MT) - does not have a lithic contact above a depth of 60 inches.
Maudlin (CO) - does not have a Bk horizon or a calcic horizon.
Meagher (MT) - does not have a lithic contact above a depth of 60 inches.
Moen (CO) - does not have a calcic horizon or a Bk horizon.
Pianohill (MT) - does not have a horizon of secondary carbonate accumulation.
Placerton (MT) - has a paralithic contact above the lithic contact.
Reeder (ND) - has a paralithic contact a depths of 20 to 40 inches.
Reedwest (MT) - does not have a lithic contact above a depth of 60 inches.
Snakejohn (UT) - has a lithic contact at 40 to 60 inches.
Sponseller (AZ) - does not have lime above a depth of 40 inches; does not have a lithic contact above a depth of 60 inches.
Trag (CO) - does not have lime above a depth of 40 inches; does not have a lithic contact above a depth of 60 inches.
Trazuni (NM) - does not have a lithic contact above 60 inches.
Tschicoma (NM) - does not have lime above a depth of 40 inches; does not have a lithic contact above a depth of 60 inches.
Ulrant (WY) - does not have a lithic contact above a depth of 40 inches.
Vida (MT) - has substratum of till that has a bulk density of 1.55 and greater; does not have a lithic contact above a depth of 60 inches.
Watrous (ND) - does not have a calcic horizon.
Wemple (MT) - has a paralithic contact at depths of 20 to 40 inches.
Williams (ND) - does not have a lithic contact above a depth of 60 inches.
Yegen (MT) - does not have a lithic contact above a depth of 60 inches.
GEOGRAPHIC SETTING:
Landform - sedimentary plains, hills and ridges.
Elevation - 4,400 to 6,200 feet.
Slope- 2 to 35 percent.
Parent material - alluvium, colluvium, or residuum from hard sandstone or fine grained igneous bedrock.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 15 to 19 inches.
Mean annual air temperature - 36 to 43 degrees F.
Frost-free period - 70 to 110 days.
DRAINAGE AND PERMEABILITY: Well drained, moderately slow permeability.
USE AND VEGETATION: Absarook soils are mainly used for rangeland and cropland. The potential native vegetation is mainly bluebunch wheatgrass, rough fescue, Idaho fescue, slender wheatgrass, parry danthonia, prairie junegrass, lupin, sticky geranium, fringed sagewort, western yarrow, larkspur, big sagebrush.
DISTRIBUTION AND EXTENT: Absarook soils are of small extent in southwestern Montana.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Gallatin County, Montana, 1997. Series proposed: Jefferson County, Montana, 1993.
REMARKS: Soil interpretation record: MT1443, MT1486, MT3028. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 13 inches (A, Bt1 horizons); an argillic horizon from 5 to 25 inches (Bt1, Bt2 horizons); a particle-size control section from 5 to 25 inches (Bt1, Bt2 horizons); a calcic horizon (Bk horizon); a lithic contact at 32 inches (R horizon). Absarook soils have a frigid temperature regime and an ustic moisture regime.