LOCATION INSULA             MN+NY
Established Series
Rev. DHP-TAF-ELB
02/2005

INSULA SERIES


The Insula series consists of shallow, well drained soils that formed in 10 to 20 inches of loamy glacial till on bedrock controlled uplands. Slopes range from 0 to 35 percent. Permeability is moderately rapid. Mean annual precipitation is about 28 inches and the mean annual temperature is about 37 degrees F.

TAXONOMIC CLASS: Loamy, isotic, frigid Lithic Dystrudepts

TYPICAL PEDON: Insula gravelly sandy loam with a 15 percent southwest facing slope under a jack pine forest at an elevation of 1,500 feet. (Colors are for moist soil unless otherwise stated.)

0i--1 1/2 to 1 inch; undecomposed and decomposing plant remains. (1/4 to 1 inch thick)

0a--1 to 0 inches; black (10YR 2/1); medium acid; mostly decomposed plant materials. (1/4 to 2 inches thick)

E--0 to 3 inches; gray (10YR 6/1) gravelly sandy loam; weak fine and medium subangular blocky structure; friable; about 25 percent rock fragments; medium acid; abrupt wavy boundary. (0 to 4 inches thick)

Bw1--3 to 6 inches; dark yellowish brown (10YR 3/4) gravelly sandy loam; weak medium subangular blocky structure and weak medium granular structure; friable; about 25 percent rock fragments; medium acid; clear smooth boundary.

Bw2--6 to 9 inches; dark brown (10YR 3/3) gravelly sandy loam; weak fine subangular blocky structure and weak medium granular structure; friable; about 25 percent rock fragments; medium acid; clear smooth boundary.

Bw3--9 to 12 inches; brown (10YR 4/3) gravelly sandy loam; weak fine subangular blocky structure and weak fine granular structure; friable; about 25 percent rock fragments; medium acid; clear smooth boundary. (Combined thickness of Bw horizons ranges from 6 to 13 inches.)

BC--12 to 15 inches; light olive brown (2.5Y 5/4) gravelly sandy loam; weak fine and medium subangular blocky structure; friable; about 25 percent rock fragments; medium acid; abrupt wavy boundary. (0 to 6 inches thick)

2R--15 inches; granite bedrock.

TYPE LOCATION: Lake County, Minnesota; NE1/4NE1/4SW1/4, sec. 24, T. 64 N., R. 49 W. (Section corners are not marked. Therefore, an accurate distance from a section corner cannot be given.)

RANGE IN CHARACTERISTICS: Thickness of solum and depth to bedrock ranges from 10 to 20 inches. Content of rock fragments, by volume, range from 10 to 35 percent in the surface and from 15 to 35 percent in the subsoil. Further, subhorizons in some pedons contain up to 45 percent of rock fragments. The rock fragments are of igneous and metamorphic origin with granites being a major component. Typically, gravel-size fragments are dominant, but cobble and boulder size fragments are significant. Stones and boulders within and on the soil range from 0 to 3 percent. In the solum, the average content of sand ranges from 35 to 65 percent and of clay from 4 to 18 percent. The fine earth fraction typically is sandy loam or fine sandy loam, but coarse sandy loam, loam, and silt loam are in some pedons. The solum ranges from very strongly acid to slightly acid.

Some pedons have an A horizon 1 to 4 inches thick. It has hue of 10YR or 7.5YR, value and chroma of 2 or 3.

The E horizon has hue of 10YR or 7.5YR, value of 4 to 6, and chroma of 1 or 2.

Some pedons have a thin Bs horizon.

The Bw horizon has hue of 7.5YR to 2.5Y, value of 3 to 5, and chroma of 3 to 6.

The bedrock is primarily granite or gabbro, but is metamorphic in some places.

COMPETING SERIES: These are the Barto and Hawksnest soils in the same family and the closely related Mesaba soils. The Barto soils lack an E horizon, typically have redder hue and bedrock is dominated by basalt. Hawksnest soils formed in till derived from sedimentary rock and typically are more acid. In addition, the rock fragments are of mostly sandstone, siltstone or shale. Mesaba soils have bedrock at a depth of 20 to 40 inches.

GEOGRAPHIC SETTING: These soils typically are on bedrock controlled ground moraines with plane to slightly convex slopes. Slope gradients are mainly 2 to 18 percent but range from 0 to to 35 percent. They formed in a 10 to 20 inch thick mantle of loamy glacial till of the Late Wisconsinan glaciation over bedrock that is dominantly granite, gabbro, and metamorphic. Mean annual temperature ranges from 35 to 44 degrees F, and mean annual precipitation ranges from 27 to 40 inches, but is dominantly 27 to 30 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the closely related Conic, Newfound and Quetico soils. They are on similar topographic positions. Conic soils are 20 to 40 inches deep and are on midslopes, Quetico soils are less than 10 inches deep and are on ridges and Newfound soils are greater than 40 inches deep and are on footslopes or concave midslopes.

DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is medium to rapid. Permeability is moderately rapid.

USE AND VEGETATION: These soils are in mixed deciduous and coniferous forest. Major resource uses are related to recreation; timber, water, and wildlife. Major species of trees are quaking aspen, balsam fir, white spruce, jack pine, red pine, and eastern white pine.

DISTRIBUTION AND EXTENT: The Laurentian Shield of northeastern Minnesota and the St. Lawrence lowlands of northern New York. Moderately extensive.

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

SERIES ESTABLISHED: Lake County, Minnesota in 1970. Source of name is Insula Lake in that county.

REMARKS: Diagnostic horizons and features are: Ochric horizon - from 0 to 3 inches (E horizon); Cambic horizon - from 3 to 15 inches (Bw and BC horizons); low base saturation.

ADDITIONAL DATA: Refer to MAES Central File Code No. 906, 908 and 916 for results of some laboratory analysis of other pedon of this series.


National Cooperative Soil Survey
U.S.A.