LOCATION LACEYCREEK MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Pachic Argiustolls
TYPICAL PEDON: Laceycreek loam, in quaking aspen stand (colors are for dry soil unless otherwise noted).
A1--0 to 18 inches; very dark gray (10YR 3/1) loam, black (10YR 2/1) moist; strong fine and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine and very fine roots and few medium and coarse roots; (pH 6.8); clear smooth boundary. (4 to 20 inches thick)
A2--18 to 23 inches; very dark grayish brown (10YR 3/2) loam, very dark brown (10YR 2/2) moist; weak medium prismatic structure parting to weak medium subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; many fine and very fine roots; many very fine and few fine tubular pores; neutral (pH 6.6); clear wavy boundary. (0 to 20 inches thick)
Bt1--23 to 30 inches; dark brown (10YR 3/3) clay loam, very dark grayish brown (10YR 3/2) moist; weak medium prismatic structure parting to moderate fine and medium subangular blocky; hard, friable, moderately sticky and moderately plastic; common fine and very fine roots; many very fine and few fine tubular pores; common faint clay films on faces of peds; neutral (pH 6.8); clear wavy boundary. (6 to 20 inches thick)
Bt2--30 to 42 inches; dark brown (10YR 4/3) clay loam, very dark grayish brown (10YR 3/2) moist; weak medium prismatic structure parting to moderate fine and medium subangular blocky; hard, friable, moderately sticky and moderately plastic; few fine and very fine roots; many very fine and few fine tubular pores; common distinct clay films on faces of peds; neutral (pH 6.8); clear wavy boundary. (10 to 26 inches thick)
2BC--42 to 60 inches; brown (10YR 5/3) gravelly sandy loam, dark brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and few fine tubular pores; 15 percent pebbles; neutral (pH 7.2).
TYPE LOCATION: Hill County, Montana; 2,300 feet north and 200 feet east of the SW corner of sec. 28, T. 29 N., R. 16 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 40 to 43 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 16 to 60 inches.
Depth to the 2BC horizon - 40 inches or more.
Some pedons have a thin O horizon.
Some pedons have an A3 horizon.
Soil phases - moist (quaking aspen overstory), cool (ponderosa pine and Douglas fir overstory).
A1 horizon - Hue: 10YR, 2.5Y, or N
Value: 3 or 4 dry; 2, 3, or N moist
Chroma: 0 or 1
Clay content: 15 to 24 percent
Rock fragments: 0 to 15 percent--0 to 10 percent pebbles, 0 to 5 percent cobbles
Reaction: pH 6.1 to 7.3
A2 horizon - Hue: 10YR, 2.5Y, or N
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 1, 2 or 3
Texture: loam or very fine sandy loam
Clay content: 15 to 24 percent
Rock fragments: 0 to 15 percent--0 to 10 percent pebbles, 0 to 5 percent cobbles
Reaction: pH 6.1 to 7.3
Bt1 horizon - Hue: 10YR or 2.5Y
Value: 3, 4, or 5 dry, 3 moist
Chroma: 2, 3 or 4
Texture: loam or clay loam
Clay content: 24 to 35 percent
Rock fragments: 0 to 10 percent--0 to 10 percent pebbles, 0 to 5 percent cobbles
Reaction: pH 6.1 to 7.3
Bt2 horizon - Hue: 10YR or 2.5Y
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2, 3 or 4
Texture: loam, clay loam, or sandy clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 25 percent--0 to 20 percent pebbles, 0 to 5 percent cobbles
Reaction: pH 6.6 to 7.8
2BC horizon - Hue: 10YR or 2.5Y
Value: 4, 5 or 6 dry, 3, 4 or 5 moist
Chroma: 2, 3 or 4
Texture: sandy loam or loam
Clay content: 5 to 20 percent
Rock fragments: 0 to 60 percent--0 to 50 percent pebbles, 0 to 10 percent cobbles
Reaction: pH 6.6 to 7.8
COMPETING SERIES:
Bowbells (ND) - has horizon of secondary carbonate accumulation.
Brycan (UT) - has a buried horizon of secondary carbonate accumulation.
Carfall (MT) - does not have a lithologic discontinuity.
Center Creek (UT) - has redox concentrations between 20 and 40 inches; is somewhat poorly drained.
Chugcreek (WY) - has a lithic contact at 20 to 40 inches.
Detra (UT) - has a lithic contact at 40 to 60 inches.
Fiesta (NM) - has hues of 7.5YR throughout.
Flaxton (ND) - has a lithologic discontinuity of glacial till at 10 to 40 inches.
Hesperus (CO) - does not have a lithologic discontinuity.
Ohwiler (CO) - does not have a lithologic discontinuity.
Pachel (MT) - has horizon of secondary carbonate accumulation.
Peta (ND) - is somewhat poorly drained; has redox features at 7 to 32 inches.
Schauson (UT) - does not have a lithologic discontinuity.
Todacheene (NM) - has hues of 5YR or 7.5YR throughout; formed in alluvium from basalt or basaltic tuff.
Trag (CO) - does not have a lithologic discontinuity.
Weed (CO) - has horizon of secondary carbonate accumulation.
GEOGRAPHIC SETTING:
Landform - alluvial fans, drainageways, hills, and stream terraces.
Elevation - 3,700 to 6,200 feet.
Slope - 2 to 45 percent.
Parent material - alluvium or colluvium from igneous and sedimentary rocks.
Climate - long, cold winters; moist springs; and warm summers.
Mean annual precipitation - 15 to 24 inches.
Mean annual air temperature - 39 to 44 degrees F.
Frost-free period - 70 to 110 days.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability above the 2BC horizon and moderately rapid through the 2BC horizon.
USE AND VEGETATION: The Laceycreek soils are used mainly for rangeland and woodland. Some areas are used for hayland and cropland. The potential native vegetation is mainly bluebunch wheatgrass, rough fescue, Idaho fescue, and Columbia needlegrass. The moist phase has an overstory of quaking aspen and the potential native understory vegetation is rose, snowberry, Saskatoon serviceberry, Canada wildrye, red raspberry, and sticky geranium. The cool phase has an overstory of ponderosa pine and Douglas fir and the potential native understory vegetation is pinegrass, common snowberry, white spirea, rose, and kinnikinnick.
DISTRIBUTION AND EXTENT: Laceycreek soils are of small extent in the Highwood and Bearpaw Mountains in central and north-central Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Chouteau County, Montana, 1992.
REMARKS: Soil interpretations record: MT1283. Diagnostic horizons and features recognized in this pedon are: a mollic color from the surface to 42 inches; an argillic horizon from 23 to 42 inches (Bt1, Bt2 horizons). Laceycreek soils have a frigid temperature regime and an ustic moisture regime bordering on udic.
ADDITIONAL DATA: Laboratory sample number S90MT-015-790