LOCATION MOLLMAN MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Eutrudepts
TYPICAL PEDON: Mollman gravelly loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 1 inch; undecomposed and slightly decomposed forest litter. (1 to 2 inches thick)
Oe--1 to 3 inches; decomposed forest litter. (0 to 2 inches thick)
E--3 to 17 inches; very pale brown (10YR 7/3) gravelly loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many fine and medium roots; common fine tubular pores; 20 percent pebbles; slightly acid (pH 6.1); clear wavy boundary. (10 to 18 inches thick)
E/Bw--17 to 34 inches; E part (80 percent) is very pale brown (10YR 7/3) very gravelly loam, yellowish brown (10YR 5/4) moist; B part (20 percent) is brownish yellow (10YR 6/6) very gravelly loam, yellowish brown (10YR 5/6) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium roots; common fine and medium tubular pores; 10 percent cobbles and 40 percent pebbles; slightly acid (pH 6.2); gradual wavy boundary. (10 to 20 inches thick)
Bw/E--34 to 41 inches; B part (55 percent) is brownish yellow (10YR 6/6) very gravelly loam, yellowish brown (10YR 5/6) moist; E part (45 percent) is pale brown (10YR 6/3) very gravelly loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium roots; common fine and medium tubular pores; 10 percent cobbles and 40 percent pebbles; slightly alkaline (pH 7.8); clear wavy boundary. (0 to 10 inches thick)
Bk1--41 to 51 inches; very pale brown (10YR 8/3) very gravelly loam, pale brown (10YR 6/3) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine and medium roots and abundant medium and fine matted roots occur at top of horizons; few medium, common fine tubular pores; 15 percent cobbles and 40 percent pebbles; disseminated lime; violently effervescent with many moderately thick segregated seams of lime in the upper part of the horizon; moderately alkaline (pH 8.0); clear wavy boundary. (8 to 35 inches thick)
Bk2--51 to 60 inches; very pale brown (10YR 8/2) very gravelly loam, light brownish gray (10YR 6/2) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine roots; 15 percent cobbles and 40 percent pebbles; disseminated lime; violently effervescent; moderately alkaline (pH 8.0)
TYPE LOCATION: Lake County, Montana; 1,000 feet south and 200 feet east of the NW corner of sec. 19, T. 26 N., R. 18 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 40 to 45 degrees F.
Moisture control section - between 4 and 12 inches.
Depth to Bk horizon - 20 to 40 inches below the mineral soil surface.
E horizon - Hue: 10YR or 2.5Y
Value: 6 or 7 dry, 5 or 6 moist
Chroma: 2 or 3
Texture: loam or silt loam
Clay content: 10 to 27 percent
Rock fragments: 0 to 60 percent--0 to 20 percent cobbles and stones, 0 to 45 percent pebbles
Reaction: pH 6.1 to 7.3
E/Bw horizon - Hue: E part 10YR or 2.5Y; B part 7.5YR or 10YR
Value: E part 6 or 7, B part 5 or 6 dry; E part 5 or 6, B part 4 or 5 moist
Chroma: E part 2, 3 or 4; B part 3, 4, 6 or 8
Texture: loam or silt loam
Clay content: 10 to 27 percent
Rock fragments: 35 to 60 percent--10 to 20 percent cobbles and stones, 25 to 40 percent pebbles
Reaction: pH 6.1 to 7.3
Bw/E horizon - Hue: B part 10YR or 2.5Y; E part 10YR or 2.5Y
Value: B part 5 or 6, E part 6 or 7 dry; B part 4, 5 or 6, E part 5 or 6 moist
Chroma: B part 3, 4, 6 or 8; E part 2, 3, or 4
Texture: loam or silt loam
Clay content: 15 to 27 percent
Rock fragments: 35 to 60 percent--10 to 20 percent cobbles and stones, 25 to 40 percent pebbles
Reaction: pH 7.4 to 7.8
Bk1 horizon - Hue: 10YR or 2.5Y
Value: 7 or 8 dry, 5 or 6 moist
Chroma: 2, 3, or 4
Texture: loam or silt loam
Clay content: 15 to 27 percent
Rock fragments: 35 to 60 percent--10 to 20 percent cobbles and stones, 25 to 40 percent pebbles
Calcium carbonate equivalent: 15 to 35 percent
Reaction: pH 7.9 to 8.4
Bk2 horizon - Hue: 10YR or 2.5Y
Value: 7 or 8 dry, 5 or 6 moist
Chroma: 2, 3, or 4
Texture: loam or silt loam
Clay content: 15 to 27 percent
Rock fragments: 35 to 60 percent--10 to 20 percent cobbles and stones; 25 to 40 percent pebbles
Calcium carbonate equivalent: 15 to 35 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Beeskove (MT) - have more than 60 percent rock fragments in the Bk horizon; have less than 15 percent clay throughout; have less than 15 percent calcium carbonate equivalent.
Posen (MI) - have horizons of illuvial organic material; do not have a mixed E/B or B/E horizon; do not have a Bk horizon.
GEOGRAPHIC SETTING:
Landform - moraines, hills, and mountains.
Elevation - 2,900 to 5,500 feet.
Slope - 0 to 60 percent.
Parent material - calcareous loamy glacial till or colluvium.
Climate - long, cold winters; moist falls and springs; warm summers.
Mean annual precipitation - 24 to 45 inches, much of which falls as snow or as spring rain.
Mean annual temperature - 38 to 45 degrees F.
Frost-free period - 70 to 90 days.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.
USE AND VEGETATION: Mollman soils are used mainly for timber production and some cherry orchards at lower elevations near Flathead Lake. The native vegetation is Douglas fir, western larch, ponderosa pine, and grand fir with an understory of twinflower, queencup beadlily, snowberry, and ninebark.
DISTRIBUTION AND EXTENT: Mollman soils are of moderate extent in western Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lake County, Montana, 1991; proposed in Lake County, Montana, 1974.
REMARKS: Soil interpretation record: MT0044, MT0780. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the mineral soil surface to 7 inches (E horizon); a cambic horizon from 17 to 41 inches (E/Bw and Bw/E horizons); calcic hroizons from 41 to 60 inches (Bk1, Bk2 horizons); a particle-size control section from 10 to 40 inches below the mineal soil surface (E, E/Bw, Bw/E, Bk1 horizons). Mollman soils have a udic moisture regime and a frigid temperature regime.
ADDITIONAL DATA: Laboratory data S84MT-047-990.