LOCATION TRIMOUNTAIN MIEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Ultic Fragiorthods
TYPICAL PEDON: Trimountain cobbly fine sandy loam, on a convex, southwest-facing slope of 35 percent, in a stand of sugar maple, yellow birch, and ironwood. (Colors are for moist soil unless otherwise stated.)
Oa--0 to 1 inches; black (N 2/0) decomposed forest litter; many fine and medium roots; extremely acid; clear wavy boundary. (0 to 3 inches thick)
E--1 to 5 inches; dark reddish gray (5YR 4/2) cobbly fine sandy loam; weak fine subangular structure; very friable; many fine and medium roots; about 9 percent gravel and 11 percent cobbles; extremely acid; clear wavy boundary. (0 to 6 inches thick)
Bhs--5 to 11 inches; dark reddish brown (5YR 3/3) fine sandy loam; moderate medium subangular blocky structure; very friable; many fine and medium and common coarse roots; about 8 percent gravel and 2 percent cobbles; very strongly acid; clear wavy boundary. (5 to 12 inches thick)
Bs--11 to 27 inches; reddish brown (5YR 4/4) gravelly fine sandy loam; moderate medium subangular blocky structure; friable; common fine and medium and few coarse roots; about 18 percent gravel and 2 percent cobbles; very strongly acid; clear wavy boundary. (10 to 20 inches thick)
2E/Bx--27 to 34 inches; reddish brown (5YR 5/3) gravelly loamy sand (E); occupies about 60 percent of the horizon surrounding peds of reddish brown (2.5YR 4/4) gravelly fine sandy loam (Bt); weak thin platy structure; very firm; few roots; common fine vesicular pores; few faint reddish brown (5YR 4/4) clay films in pores and root channels; about 17 percent gravel and 6 percent cobbles; very strongly acid; clear wavy boundary. (6 to 15 inches thick)
2Btx--34 to 46 inches; reddish brown (5YR 4/4) gravelly loamy sand; massive; very firm; few very fine vesicular pores; few faint reddish brown (5YR 4/3) clay films in pores; about 30 percent gravel and 3 percent cobbles; very strongly acid; gradual wavy boundary. (0 to 20 inches thick)
2C1--46 to 56 inches; reddish brown (5YR 4/4) gravelly fine sand; massive; firm; about 17 percent gravel and 3 percent cobbles; strongly acid; clear wavy boundary. (0 to 12 inches thick)
3C2--56 to 80 inches; reddish brown (5YR 4/4) extremely gravelly coarse sand; massive; friable; about 65 percent gravel and 3 percent cobbles; strongly acid.
TYPE LOCATION: Houghton County, Michigan; about 1 mile west of the town of Trimountain; located about 1,850 feet west and 1,850 feet north of the southeast corner of section 24, T. 54 N., R. 35 W.; USGS South Range topographic quadrangle; lat. 47 degrees 03 minutes 35 seconds N. and long. 88 degrees 41 minutes 14 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: The thickness of the loamy mantle ranges from 15 to 32 inches. Depth to the fragipan ranges from 14 to 30 inches. Thickness of the solum ranges from 24 to 60 inches. The soil ranges from extremely acid to slightly acid. Gravel content ranges from 0 to 25 percent in the A, E, and B horizons, 5 to 35 percent in the 2E/Bx and 2BC horizons and 15 to 70 percent in the 2C horizons. Cobble and stone content ranges from 1 to 15 percent in the A, E, and B horizons and from 0 to 25 percent in the 2E/Bx, 2Btx and 2C horizons. The volume of rock fragments averages from 10 to 30 percent in the control section.
The A horizon, where present, has hue of 5YR or 7.5YR, value of 2 or 3, and chroma of 1 or 2. The E horizon has hue of 7.5YR or 5YR, value of 4 to 6, and chroma of 1 or 2. The A and E horizons are gravelly or cobbly analogues of fine sandy loam, very fine sandy loam, or loamy fine sand.
The Bhs horizon has hue of 5YR or 7.5YR and value and chroma of 2 or 3. The Bs horizon has hue of 5YR or 7.5YR, value of 3 to 5, and chroma of 3 or 4. The Bs horizon is subdivided in some pedons. The B horizons are fine sandy loam, very fine sandy loam, loamy fine sand, or the gravelly or cobbly analogues of these textures.
The E part of the 2E/Bx horizon has hue of 5YR or 7.5YR, value of 4 to 6, and chroma of 2 or 3. The B part has hue of 2.5YR to 7.5YR, value of 4 or 5, and chroma of 4 to 6. The 2E/Bx horizon is fine sandy loam, sandy loam, loamy sand, loamy fine sand, or the gravelly analogues of these textures. The fragipan in this horizon is very hard or extremely hard when dry and firm to extremely firm when moist.
The 2Btx horizon has colors and textures similar to the B part of the 2E/Bx horizon.
The 2C horizon has hue of 5YR or 7.5YR, value of 4 or 5, and chroma of 3 or 4. It is gravelly fine sand, gravelly loamy fine sand, gravelly loamy very fine sand, or the very gravelly analogues of these textures.
The 3C horizon has hue of 5YR or 7.5YR, value of 4 or 5, and chroma of 3 to 6. It is gravelly sand, gravelly coarse sand, gravelly loamy sand, gravelly sandy loam, gravelly loamy fine sand, gravelly fine sandy loam, or the very gravelly analogues of these textures. The material contains abundant basalt and andesite amygdaloids and conglomerates.
COMPETING SERIES: There are none. The closely related Schweitzer, Frohling and Tokiahok soils have greater than 35 percent base saturation by sum of bases in some part of an argillic horizon.
GEOGRAPHIC SETTING: Trimountain soils are on ground moraines and end moraines of Wisconsinan age. They have formed in a loamy eolian mantle underlain by gravelly loamy or sandy glacial till derived from the Portage Lake Lava Series. Slope ranges from 8 to 70 percent. The local climate is affected by Lake Superior causing high snowfall. Mean annual precipitation ranges from 30 to 36 inches. Mean annual air temperature ranges from 40 to 45 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gratiot, Lac La Belle, Michigamme, Montreal, Net, Paavola, Sabattis and Witbeck soils. The well drained Lac La Belle and Michigamme soils are in similar landscape positions. . The moderately well drained Montreal and Paavola soils are in slightly lower landscape positions than the Trimountain soils. The somewhat poorly drained Gratiot and Net soils and poorly drained Sabattis and Witbeck soils are in depressions and drainageways.
DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is medium to high, dependent on slope. Permeability is moderate in the upper part, very slow in the fragipan, and moderate or moderately rapid in the lower part of the pedon.
USE AND VEGETATION: Most areas are forested with sugar maple, ironwood, American basswood, and yellow birch being the major species.
DISTRIBUTION AND EXTENT: Northwestern part of the Upper Peninsula of Michigan, primarily on the Keweenaw Peninsula. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Houghton County, Michigan, 1989.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
ochric horizon--the zone from the surface to a depth of 5 inches (Oa and E horizons);
albic horizon--the zone from a depth of 1 to 5 inches (E horizon);
spodic horizon--the zone from a depth of 5 to 27 inches (Bhs and Bs horizons);
fragipan--the zone from a depth of 27 to 46 inches (2E/Bx and 2Btxhorizon).
glossic horizon--the zone from a depth of 27 to 34 inches (2E/Bx horizon);
argillic horizon--the zone from a depth of 27 to 46 inches (2E/Bx and 2Btx horizons) - this zone meets the requirements for an argillic horizon because of the lithologic discontinuity and the presence of clay films;
ultic subgroup--the argillic horizon has base saturation less than 35 percent.
The moderately well drained phase is no longer within the series concept.
ADDITIONAL DATA: For laboratory data on this pedon refer to S86MI-061-002 from the NSSL