LOCATION MICHELSON MT+WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Calcic Argicryolls
TYPICAL PEDON: Michelson cobbly loam - native sod. (Colors are for dry soil unless otherwise stated.)
A--0 to 13 cm; very dark grayish brown (10YR 3/2) cobbly loam, black (10YR 2/1) moist; weak coarse prismatic structure that separates to weak fine granules; slightly hard, very friable, nonsticky and slightly plastic; many fine and very fine roots; 35 percent rounded gravel and cobbles; neutral (pH 6.6); clear irregular boundary. (10 to 18 cm thick)
Bt--13 to 46 cm; yellowish brown (10YR 5/4) clay loam, dark brown (10YR 3/3) moist, grading with depth to brown (10YR 4/3) moist; strong medium prismatic structure that separates to moderate medium blocks; hard, friable, slightly sticky and slightly plastic; common fine and very fine roots with concentration of roots between prisms; few rounded gravel and cobbles; slightly acid (pH 6.4) in upper part and neutral (pH 6.9) in the lower part; clear wavy boundary. (25 to 51 cm thick)
2Bk1--46 to 86 cm; pink (5YR 8/3) clay loam, reddish brown (2.5YR 4/3) moist; weak thin platy structure; hard, friable, slightly sticky and moderately plastic; few medium and fine roots; few rounded gravel and cobbles; strongly calcareous with segregated lime as seams of light brownish gray (2.5Y 6/2) and pale yellow (2.5Y 8/2) and as coatings on gravel and cobbles; clear wavy boundary.
2Bk2--86 to 97 cm; pink (5YR 7/4) clay loam, reddish yellow (5YR 6/6) moist; weak thin platy structure; hard, friable, moderately sticky and moderately plastic; few fine roots; strongly calcareous with segregated lime as seams and mottlings; few rounded gravel and cobbles; clear wavy boundary. (2Bk horizons are 38 to 76 cm thick)
3Bk3--97 to 122 cm; light brown (7.5YR 6/4) extremely gravelly sandy clay loam, yellowish red (5YR 5/6) moist; massive; very hard, firm, very sticky and moderately plastic; few fine roots; strongly calcareous with pink (7.5YR 8/4) lime coatings on gravel and cobbles, mostly on bottom sides; 70 percent rounded gravel and cobbles; clear wavy boundary. (13 to 51 cm thick)
4Btb--122 to 183 cm; reddish yellow (5YR 6/6) extremely gravelly sandy clay, yellowish red (5YR 4/6) moist; massive; very hard, friable, moderately sticky and moderately plastic; no roots; 70 percent rounded gravel and cobbles; distinct light-reflective coating on walls of few tubular pores, coating some gravels and bridging sand; noncalcareous except for segregated lime coating some gravel and cobbles; slightly alkaline (pH 7.5).
TYPE LOCATION: Glacier County, Montana; 1,600 feet west and 500 feet north of center of section 2, T.34N., R.12W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 38 to 100 cm. Gravel, cobbles, and some stones occur on and in the soil pedon, ranging from 5 to 40 percent of volume in the A horizon, 5 to 15 percent of volume above a minimum depth of 76 cm, and from 35 to 80 percent of volume below a maximum depth of 102 cm. Base saturation ranges from 85 to 100 percent. The mean annual soil temperature ranges from 4 to 7 degrees C. The average summer soil temperature ranges from 11 to 15 degrees C. The average winter soil temperature is about -6 degrees C. Soil temperature at 50 cm is warmer than 5 degrees C. from about May 15 to November 1. The soils are dry to 50 cm for about 40 cumulative days during the growing season. The mollic epipedon ranges from 18 to 28 cm thick and includes the upper part of the Bt horizon.
The A horizon has hue of 10YR or 7.5YR, value of 3 through 5 dry and 2 or 3 moist and chroma of 1 through 3.
The Bt horizon has hue of 10YR or 7.5YR, value of 5 or 6 dry and 3 or 4 moist and chroma of 2 through 4. It is heavy loam to light clay loam with 25 to 35 percent clay and 30 to 40 percent silt plus very fine sand. It is neutral to slightly alkaline (pH 6.6 to 7.8).
The 2Bk1, 2Bk2, and 3Bk3 horizons, have hues of 2.5Y through 2.5YR, values of 6 through 8 dry and 4 through 6 moist and chromas of 3 through 6. They have 15 to 45 percent CaC03 equivalent.
The 4Btb horizon of the typifying pedon occurs at depths greater than 102 cm and extends below 152 cm in most pedons.
COMPETING SERIES:
Accola (MT) - does not have a lithologic discontinuity.
Oro Fino (MT) - is sandy-skeletal at 40 to 60 inches.
Philipsburg (MT) - does not have a buried argillic horizon below a depth of 40 inches.
GEOGRAPHIC SETTING: Michelson soils are on the nearly level to gently sloping, high, old terraces and their sloping sides. They formed in old alluvium from Cretaceous shales and quartzites and argillite rocks. Mean annual air temperature ranges from 3 to 7 degrees C., mean summer air temperature ranges from 13 to 15 degrees C. and mean winter temperature is -7 or -6 degrees C. Mean annual precipitation ranges from 381 to 610 mm, most of which falls in spring, summer and fall months of May through September. Annual snowfall ranges from 1270 to 3810 mm.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Adel, Gelkie, Pishkun, and Redchief series. Adel soils have mollic epipedons more than 40 mm thick and lack argillic horizons. Gelkie soils lack calcic horizons. Pishkun soils have ochric epipedons in loamy-skeletal profiles. Redchief soils have more than 35 percent coarse fragments in the control section.
DRAINAGE AND PERMEABILITY: Well-drained; slow to moderate runoff; moderate permeability.
USE AND VEGETATION: Used mostly for range. Native grasses are western wheatgrass, bluebunch wheatgrass, rough fescue and Idaho fescue.
DISTRIBUTION AND EXTENT: Montana and Wyoming on high terraces adjacent to and in valleys of the Rocky Mountains. The Michelson series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Glacier County (Blackfeet Reservation-Cut Bank Area), Montana, 1969