LOCATION BRIMSON            MN
Established Series
Rev. PCW-RTR-MPD-MBW
12/2008

BRIMSON SERIES


The Brimson series consists of very deep, somewhat poorly drained soils that formed in a friable loamy mantle and the underlying dense loamy Rainy Lobe till on drumlins and moraines. Slope ranges from 0 to 8 percent. Mean annual air temperature is about 3 degrees C. and mean annual precipitation is about 700 millimeters.

TAXONOMIC CLASS: Coarse-loamy, isotic, frigid Aquic Dystric Eutrudepts

TYPICAL PEDON: Brimson stony fine sandy loam with a linear slope of 3 percent on a drumlin under a stand of red pine. Elevation of about 485 meters. (Colors are for moist soil unless otherwise stated.)

A--0 to 13 centimeters; very dark grayish brown (10YR 3/2) stony fine sandy loam, grayish brown (10YR 5/2) dry; moderate medium and fine granular structure; friable; many fine and medium roots and few coarse; about 7 percent gravel, 6 percent cobbles and 6 percent stones; strongly acid; clear wavy boundary. (5 to 15 centimeters thick)

Bw1--13 to 28 centimeters; brown (7.5YR 4/4) stony sandy loam; weak medium and fine subangular blocky structure; friable; many fine and medium roots and few coarse; about 7 percent gravel, 6 percent cobbles and 6 percent stones; moderately acid; clear wavy boundary.

Bw2--28 to 43 centimeters; dark yellowish brown (10YR 4/4) cobbly sandy loam; weak moderate subangular blocky structure; friable; many fine and medium roots; few fine distinct strong brown (7.5YR 5/6) Fe concentrations; about 7 percent gravel, 5 percent cobbles and 3 percent stones; moderately acid; clear wavy boundary.

Bw3--43 to 58 centimeters; brown (7.5YR 4/4) cobbly sandy loam; weak medium subangular blocky structure; friable; common fine and very fine roots; common fine distinct strong brown (7.5YR 5/6) Fe concentrations and common fine prominent grayish brown (10YR 5/2) Fe depletions; about 7 percent gravel, 5 percent cobbles and 3 percent stones; moderately acid; clear wavy boundary.

Bw4--58 to 89 centimeters; brown (10YR 4/3) cobbly sandy loam; weak medium subangular blocky structure; friable; few fine and very fine roots; common fine distinct yellowish brown (10YR 5/6) Fe concentrations and common fine distinct grayish brown (10YR 5/2) Fe depletions in an elongate direction with the slope; about 8 percent gravel and 5 percent cobbles and 3 percent stones; slightly acid; clear wavy boundary. (Combined thickness of the Bw horizons is 36 to 91 centimeters)

2BCd1--89 to 124 centimeters; dark grayish brown (10YR 4/2) gravelly sandy loam; moderate very coarse and extremely coarse prismatic structure parting to moderate fine and medium platy, few 2 to 3 millimeter oblique fractures 15 centimeters to 1 meter apart; very firm; common fine distinct dark yellowish brown (10YR 4/6) Fe concentrations along fracture faces; about 20 percent gravel and 5 percent cobbles; neutral; gradual wavy boundary.

2BCd2--124 to 203 centimeters; dark grayish brown (10YR 4/2) gravelly sandy loam; moderate very coarse and extremely coarse prismatic structure parting to moderate fine and medium platy, few 2 to 3 millimeter oblique fractures 15 centimeters to 1 meter apart; very firm; about 20 percent gravel and 5 percent cobbles; neutral.

TYPE LOCATION: Major Land Resource Area (MLRA) 93A-Superior Stony and Rocky Loamy Plains and Hills, Western Part, St. Louis County (Duluth Part), Minnesota subset; about 30 miles north of Duluth; 650 feet north and 400 feet east of the southwest corner, section 17, T. 55 N., R. 13 W.; USGS Boulder Lake Reservoir NE Quadrangle, latitude 47 degrees 14 minutes 36 seconds N. and longitude 92 degrees 1 minute 31 seconds W., NAD 27.

RANGE IN CHARACTERISTICS: The thickness of the loamy mantle and depth to the 2BCd (densic contact) ranges from 50 to 100 centimeters
Depth to free carbonates--greater than 200 centimeters
Rock fragment content of the particle size control section (weighted average)--less than 35 percent by volume

Some pedons have a thin O horizon (duff layer).

A horizon:
Hue--7.5YR or 10YR
Value--2 or 3
Chroma--1 to 3
Texture--stony fine sandy loam, stony sandy loam, stony loam, or their non-stony, gravelly and cobbly analogues
Rock fragment content--total 2 to 30 percent; with 2 to 15 percent gravel, 0 to 20 percent cobbles and 0 to 10 percent stones and boulders
Reaction--strongly acid to slightly acid

Some pedons have a thin E horizon.

Bw horizon:
Hue--7.5YR or 10YR
Value--3 to 5
Chroma--3 to 6
Texture--sandy loam, fine sandy loam, loam or their gravelly, cobbly and stony analogues
Rock fragment content--total 2 to 30 percent; with 2 to 15 percent gravel, 0 to 20 percent cobbles and 0 to 10 percent stones and boulders
Reaction--strongly acid to slightly acid

Some pedons have a BC or 2Bw horizon.

2BCd horizon:
Hue--10YR
Value--3 or 4
Chroma--2 or 3
Texture--gravelly sandy loam, gravelly loamy sand, gravelly loamy coarse sand, gravelly coarse sandy loam or their very gravelly analogues
Rock fragment content--total 15 to 45 percent; with 15 to 35 percent gravel, 0 to 10 percent cobbles and 0 to 2 percent stones and boulders
Reaction--moderately acid to neutral
It typically has 1 to 3 millimeter oblique fractures 10 centimeters to 3 meters apart.

COMPETING SERIES: These are the Gnesen, Hermantown, Kenduskeag(T), and Pequaywan series.
Gnesen--have coarse textured outwash in the lower third of the series control section
Pequaywan--have coarse textured outwash in the lower third of the series control section and have saturation no shallower than 75 centimeters below the surface
Hermantown--are underlain by dense Superior Lobe till with 2.5YR or 5YR hue
Kenduskeag(T)--have sola terminated by phyllite, calcareous metasiltstone and pelitic limestone

GEOGRAPHIC SETTING:
Parent material--a friable loamy mantle and the underlying dense, firm and very firm, loamy Rainy Lobe till
Landform--on plane and slightly convex slopes on back slopes and summits of drumlins and moraines
Slope--0 to 8 percent
Mean annual air temperature--2 to 4 degrees C
Mean annual precipitation--635 to 760 millimeters
Annual freeze free period--120 to 175 days
Elevation above sea level--185 to 640 meters

GEOGRAPHICALLY ASSOCIATED SOILS:
Near the type location, these are the Bugcreek, Nevens, and Toimi soils.
Bugcreek--are in drainageways and depressions or on the edges of bogs and swamps and are in the Typic Humaquepts subgroup
Nevens--are on lower lying or less sloping positions on the landscape and are in the Typic Epiaquepts subgroup
Toimi--are on higher lying or more sloping positions on the landscape and are in the Oxyaquic Eutrudepts subgroup

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained--The Brimson soils have perched seasonal high saturation at depths as high as 15 centimeters below the surface during the spring in normal years. At the contact between the loamy mantle and dense till, there commonly is a concentration of redoximorphic features that has shallow penetration into the dense till along fractures and rock sockets.
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second (moderately high) in the loamy mantle and 0.01 to 0.10 micrometers per second (low) in the underlying dense till

USE AND VEGETATION: These soils are used mainly for timber production. Native vegetation was mixed deciduous and coniferous forest. Major tree species are quaking aspen, paper birch and balsam fir.

DISTRIBUTION AND EXTENT:
Physiographic Division--Laurentian Upland
Physiographic Province--Superior Upland Province
Physiographic sections--(undefined)
MLRA--Superior Stony and Rocky Loamy Plains and Hills, Western Part(93A)
LRR K; northeastern Minnesota
Extent--moderate

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: St. Louis County, Minnesota (Duluth subset), 2007

REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters
series control section--the zone from the surface to a depth of 150 centimeters

Diagnostic horizons and features recognized in this pedon include:
ochric epipedon--the zone from the surface to a depth of 13 centimeters (A horizon);
cambic horizon--the zone from a depth of 13 to 89 centimeters (Bw horizons);
aquic moisture condition based on the redoximorphic depletions within 60 centimeters of the mineral soil surface;
dystric subgroup based on no free carbonates above 100 centimeters;
isotic mineralogy based on 1500 kPa water to measured clay ratio of 0.6 or greater.

The previous classification was coarse-loamy, mixed, nonacid, frigid Aeric Epiaquepts.

The designation of the 2BCd horizon is based on fractures and platy structure in the densic material. Clay and silt translocation can be seen between the horizontal plates when broken apart.

Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006

ADDITIONAL DATA: Refer to NSSL pedon S95-MN137-540 for additional analysis.


National Cooperative Soil Survey
U.S.A.