LOCATION MICHIGAMME MI+MN WIEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Fragic Haplorthods
TYPICAL PEDON: Michigamme cobbly silt loam - forested. (Colors are for moist soil unless otherwise stated).
Oi--0 to 1 inches; slightly decomposed plant material; extremely acid; abrupt smooth boundary.
A--1 to 3 inches; dark reddish brown (5YR 2/2) cobbly silt loam, dark reddish gray (5YR 4/2) dry; moderate fine granular structure; very friable; many fine roots; about 2 percent gravel and 30 percent cobbles; extremely acid; clear smooth boundary. (0 to 4 inches thick).
E--3 to 5 inches; brown (7.5YR 5/2) cobbly silt loam; weak medium subangular blocky structure; friable; many fine roots; about 2 percent gravel and 30 percent cobbles; extremely acid; clear wavy boundary. (0 to 5 inches thick).
Bhs--5 to 8 inches; dark reddish brown (5YR 3/2) silt loam; moderate medium subangular blocky structure parting to weak fine granular; friable; many fine and medium roots; about 3 percent gravel and 10 percent cobbles; extremely acid; clear wavy boundary. (3 to 7 inches thick)
Bs1--8 to 15 inches; dark reddish brown (5YR 3/4) silt loam; weak medium subangular blocky structure; friable; many fine and medium roots; about 2 percent gravel; very strongly acid; gradual wavy boundary.
Bs2--15 to 21 inches; reddish brown (5YR 4/4) silt loam; weak medium subangular blocky structure; friable; common fine roots; about 3 percent gravel and 10 percent cobbles; strongly acid; gradual wavy boundary.
Bs3--21 to 25 inches; brown (7.5YR 4/4) cobbly silt loam; weak fine subangular blocky structure; friable; few fine roots; about 8 percent gravel and 27 percent cobbles; strongly acid; gradual irregular boundary. (Combined thickness of the Bs horizons are 5 to 22 inches thick)
2E/Bx--25 to 32 inches; brown (10YR 5/3) gravelly fine sandy occupying about 55 percent of the horizon (E) surrounding dark reddish brown (5YR 3/4) gravelly fine sandy loam (B); weak thick platy structure parting to weak fine subangular blocky structure; friable; brittle and firm in about 35 percent of the horizon; few fine roots between ped faces; about 20 percent gravel and 10 percent cobbles; strongly acid; abrupt smooth boundary. (2 to 8 inches thick)
3R--32 inches; metamorphic bedrock; one-half inch coating of weak red (2.5YR 5/2) firm loam on top of rock.
TYPE LOCATION: Baraga County, Michigan; about 4 miles south of Covington; 2,200 feet south and 300 feet east of the northwest corner of sec. 12, T. 47 N., R. 34 W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 20 to 40 inches. Texture of the solum includes silt loam, loam, very fine sandy loam, fine sandy loam, sandy loam or the gravelly or cobbly analogs of these textures. Rock fragments range from 0 to 35 percent as a weighted average throughout. Volume of gravel ranges from 0 to 25 percent and volume of cobbles and stones ranges from 0 to 35 percent throughout. The pedon ranges from extremely acid to slightly acid.
The A horizon has hue of 5YR, 7.5YR, or 10YR; value of 2 to 4; and chroma of 1 to 3. The E horizon has hue of 5YR or 7.5YR and value of 4 to 6 and chroma of 2 or 3.
The Bhs horizon has value and chroma of 2 or 3. The Bs horizon has hue of 2.5YR, 5YR, or 7.5YR; value of 3 to 6; and chroma of 3 to 6.
The 2E/Bx horizon has hue of 5YR, 7.5YR, 10YR, or 2.5Y; value of 3 to 6; and chroma of 2 to 4. It is loamy sand, sandy loam, fine sandy loam, or gravelly or cobbly analogs of these textures. Fragic properties commonly occupy 30 to 60 percent of the 2E/B horizon, but range to above 60 percent when the horizon thickness is less than 6 inches.
Some pedons have a 2B/Ex horizon with colors and textures similar to the 2E/B horizon.
Some pedons have 2C or 2Cx horizons. They are firm and have fragipan-like characteristics in some pedons.
The underlying bedrock is typically igneous or metamorphic but less commonly is conglomerate.
COMPETING SERIES: There are no competing series. The closely related Dishno soil is moderately well drained and has a lithic contact between 40 and 60 inches. The Peshekee and Arcadian soils have a lithic contact between 10 and 20 inches.
GEOGRAPHIC SETTING: Michigamme soils are on ground moraines which have a thin mantle of silty or loamy material over glacial till, underlain by bedrock. Slopes range from 1 to 75 percent, but are typically greater than 15 percent. Mean annual precipitation of 26 to 33 inches and the mean annual temperature is 40 to 45 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the moderately well drained, very deep, Champion, Gogebic, and Wakefield soils on ground moraines. The well drained Schweitzer is associated in steeply sloping areas. The deep, moderately well drained Dishno soil is a common associate on less steep areas.
DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is medium to high, dependent on slope. Permeability is moderate in the upper part of the solum and slow or very slow in the lower part.
USE AND VEGETATION: A few areas are cleared and used for hay and pasture. Most areas of Michigamme soil are in second growth timber and support stands of sugar maple and red maple, yellow birch, eastern hemlock, paper birch, and aspen.
DISTRIBUTION AND EXTENT: Western and Central Upper Peninsula of Michigan and possibly Wisconsin and northeastern Minnesota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota.
SERIES ESTABLISHED: Baraga County, Michigan, 1984.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
ochric epipedon - surface to 3 inches (A horizon);
albic horizon - 3 to 5 inches (E horizon);
spodic horizon - 5 to 25 inches (Bhs, Bs1, Bs2 and Bs3 horizons);.
Fragic feature - 30 percent or more of a layer 6 inches or more in thickness is brittle and has firm or firmer rupture resistance class. (E/Bx horizon).
The moderately well drained phase is no longer within the series concept.
The series classification was changed to reflect additional observations of the series across its geographic range.
ADDITIONAL DATA: Refer to S78MI-013-007 for lab data on the typical pedon.