LOCATION MACMEAL MT+WYEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Haplustalfs
TYPICAL PEDON: Macmeal gravelly loam, forested (colors are for dry soil unless otherwise noted).
0i1--2 inches to 1-inch; mat of twigs, leaves, and dead plants.
0i2--1-inch to 0; layer of slightly decomposed organic material.
E--0 to 7 inches; pale brown (10YR 6/3) gravelly loam, dark brown (10YR 4/3) moist; weak fine and very fine granular structure; soft, very friable, slightly sticky and slightly plastic; common fine and medium roots; common fine pores; many unstained sand and silt grains; 20 percent pebbles, 5 percent flagstones; neutral (pH 7.0); clear wavy boundary. (3 to 12 inches thick)
Bt1--7 to 14 inches; yellowish brown (10YR 5/4) very gravelly clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine granular structure; hard, friable, sticky and plastic; common fine and very fine roots; common fine and very fine pores; 50 percent pebbles, 5 percent flagstones; neutral (pH 7.0); clear wavy boundary.
Bt2--14 to 32 inches; yellowish brown (10YR 5/4) extremely channery clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium and fine blocky structure; very hard, firm, sticky and plastic; few fine and very fine roots; common very fine pores; few faint clay films on faces of peds; 50 percent channers, 15 percent flagstones; neutral; gradual wavy boundary.
Bt3--32 to 48 inches; yellowish brown (10YR 5/4) extremely channery clay loam dark yellowish brown (10YR 4/4) moist; moderate medium and fine blocky structure; very hard, firm, sticky and plastic; common very fine pores; few faint clay films on faces of peds; 50 percent channers, 15 percent flagstones; neutral; clear wavy boundary. (Combined thickness of Bt horizons is 20 to 45 inches)
Bk--48 to 60 inches; brown (10YR 5/3) extremely flaggy clay loam, dark brown (10YR 4/3) moist; moderate medium and fine subangular blocky structure; very hard, friable, sticky and plastic; 40 channers, 25 percent flagstones; common distinct lime coats on underside of fragments; slightly alkaline.
TYPE LOCATION: Blaine County, Montana; about 550 feet west and 1,600 feet north of the SE corner of sec. 15, T. 26 N., R. 24 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 38 to 44 degrees F.
Moisture control section - between 4 and 12 inches.
Depth to Bk horizon - 24 to 55 inches.
E horizon - Hue: 10YR or 7.5YR Value: 5, 6, or 7 dry; 4, 5, or 6 moist Chroma: 2 or 3 Texture: loam or clay loam Clay content: 10 to 30 percent Rock fragments: 15 to 55 percent--0 to 10 percent stones, 5 to 25 percent cobbles or flagstones, 10 to 20 percent pebbles or channers Reaction: pH 6.1 to 7.3
Bt horizons - Hue: 10YR or 7.5YR Value: 5 or 6 dry; 4 or 5 moist Chroma: 3 or 4 Clay content: 27 to 35 percent Rock fragments: 35 to 70 percent--0 to 5 percent stones, 5 to 15 percent cobbles or flagstones, 30 to 50 percent pebbles or channers Reaction: pH 6.1 to 7.3
Bk horizon - Hue: 10YR or 7.5YR Value: 5, 6, or 7 dry; 4, 5, or 6 moist Chroma: 2, 3, or 4 Clay content: 27 to 35 percent Rock fragments: 35 to 75 percent--5 to 10 percent stones, 5 to 25 percent cobbles or flagstones, 25 to 40 percent pebbles or channers Reaction: pH 7.4 to 8.4
COMPETING SERIES:
Abrue (NM) - has igneous bedrock at 40 to 60 inches; does not have horizon of secondary carbonate accumulation.
Geohrock (MT) - does not have O or E horizons; has accumulation of carbonates at 6 to 10 inches.
Grizzly (SD) - does not have horizon of carbonate accumulation; has more than 35 percent clay in the Bt2 horizon.
Krakow (MI) - does not have horizon of secondary carbonate accumulation; formed in till.
Pactola (SD) - does not have horizon of secondary carbonate accumulation; has fractured bedrock between 20 and 50 inches; has glossic horizon.
Rockoa (SD) - does not have horizon of secondary carbonate accumulation; is stony to extremely stony throughout.
Tecolote (NM) - does not have horizon of secondary carbonate accumulation; has a glossic horizon above 60 inches.
Trapps (MT) - has Bt horizon 10 to 20 inches thick.
Vanocker (SD) - does not have an E horizon; is calcareous at 4 to 25 inches.
Wahatoya (CO) - has a lithic contact at 20 to 40 inches.
Yourame (MT) - has mixed E/Bt horizon.
Yreka (MT) - has mixed E/Bt horizon; does not have horizon of secondary carbonate accumulation.
GEOGRAPHIC SETTING:
Landform - mountains, hills, alluvial fans and stream terraces
Elevation - 4,000 to 6,500 feet.
Slope- 4 to 60 percent.
Parent material - alluvium and colluvium from igneous and metamorphic rocks.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 17 to 25 inches.
Mean air annual temperature - 38 to 44 degrees F.
Frost-free period - 80 to 100 days.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Macmeal soils are used mainly for range and woodland. Potential native vegetation is mainly green needlegrass, bluebunch wheatgrass, creeping juniper, snowberry, wild rosebush, kinnikinnick, and low to moderate density stands of ponderosa pine.
DISTRIBUTION AND EXTENT: Macmeal soils are of small extent in the mountains in central Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Blaine County, Montana, 1976.
REMARKS: Soil Interpretations Record: MT0285 and MT0784.
Diagnostic horizons and features recognized in this pedon are: ochric epipedon - from the soil surface to 7 inches (E horizon); argillic horizon - from 7 to 48 inches (Bt horizons); horizon of carbonate accumulation - from 48 to 60 inches (Bk horizon); particle-size control section - from 7 to 27 inches (Bt1 and Bt2 horizons). Macmeal soils have a frigid temperature regime and an ustic moisture regime.