LOCATION LAPOIN WIEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, frigid Alfic Oxyaquic Haplorthods
TYPICAL PEDON: Lapoin loam, on a convex, northwest facing, 5 percent slope, in a forested area, at an elevation of 770 feet. (Colors are for moist soil unless otherwise stated.)
Oa--0 to 1 inches; very dark gray (5YR 3/1) highly decomposed plant material; about 10 percent fibers and less than 5 percent rubbed; weak fine granular structure; very friable; many fine, medium and coarse roots; common uncoated quartz sand grains; very strongly acid; abrupt wavy boundary. (0 to 3 inches thick)
E--1 to 4 inches; dark reddish gray (5YR 4/2) loam, pinkish gray (5YR 7/2) dry; weak medium subangular blocky structure; friable; many fine and medium and common coarse roots; about 3 percent gravel; about 3 percent cobbles; about 1 percent stones; very strongly acid; abrupt wavy boundary. (1 to 5 inches thick)
Bs--4 to 7 inches; reddish brown (5YR 4/3) loam; weak medium subangular blocky structure; friable; many fine and medium and few coarse roots; about 3 percent gravel; about 3 percent cobbles; about 1 percent stones; very strongly acid; abrupt wavy boundary. (1 to 10 inches thick)
2B/E--7 to 19 inches; 70 percent dark reddish brown (2.5YR 3/4) clay (Bt); moderate fine angular blocky structure; firm; common faint reddish brown (2.5YR 4/4) clay films on faces of peds; slightly acid; penetrated by tongues of reddish brown (5YR 5/3) loam (E), pink (5YR 7/3) dry; moderate medium subangular blocky structure; firm; few medium distinct yellowish red (5YR 5/6) masses of iron accumulation; many fine and common medium roots; about 2 percent gravel; about 2 percent cobbles; about 1 percent stones; strongly acid; gradual wavy boundary.(Glossic horizon - 2 to 20 inches thick)
2Bt1--19 to 29 inches; reddish brown (2.5YR 4/4) clay; moderate medium angular blocky structure; firm; common fine, and few medium roots between peds; common faint dark reddish brown (2.5YR 3/4) clay films on faces of peds; about 2 percent gravel; about 2 percent cobbles; about 1 percent stones; neutral; gradual wavy boundary.
2Bt2--29 to 34 inches; reddish brown (2.5YR 4/4) clay; moderate medium subangular blocky structure; firm; few fine roots between peds; few faint dark reddish brown (2.5YR 3/4) clay films on faces of peds; about 2 percent gravel; about 2 percent cobbles; about 1 percent stones; slightly alkaline; abrupt wavy boundary. (Combined thickness of the 2Bt horizon ranges from 15 to 21 inches.)
3C--34 to 39 inches; reddish brown (2.5YR 4/4) sandy loam; massive; friable; about 5 percent gravel; about 2 percent cobbles; neutral; abrupt smooth boundary. (0 to 9 inches thick)
4R--39 inches; reddish brown (5YR 4/4) sandstone bedrock.
TYPE LOCATION: Bayfield County, Wisconsin; about 2.5 miles north and 1.5 miles east of Red Cliff; 1600 feet north and 1000 feet west of the southeast corner of sec. 17, T. 51 N., R. 3 W.; USGS York Island, WI topographic quadrangle; lat. 46 degrees 53 minutes 40 seconds N. and long. 90 degrees 45 minutes 38 seconds W.
RANGE IN CHARACTERISTICS: (Unless otherwise stated, depth and thickness are measured from the top of the mineral soil.) Depth to the base of the argillic horizon and to a lithic contact with sandstone range from 20 to 40 inches and in some pedons they coincide. Thickness of the loamy mantle ranges from 3 to 10 inches. The weighted average clay content of the particle-size control section ranges from 35 to 60 percent. Free carbonates are in some pedons at a depth of 24 to 40 inches. Rock fragments are of mixed lithology. Volume of gravel ranges from 0 to 5 percent throughout. Volume of cobbles ranges from 0 to 3 percent throughout. Volume of stones ranges from 0 to 1 percent throughout. Redox accumulations are below the spodic horizon and within 40 inches. Saturation occurs within 40 inches for 1 month or more per year in most years.
The O horizon has hue of 5YR, 7.5YR, or 10YR or is neutral, value of 2 or 3 and chroma of 0 to 3. The O horizon is a mat of highly decomposed forest litter. Reaction ranges from extremely acid to strongly acid.
Some pedons have an A horizon with hue of 5YR, 7.5YR, or 10YR; value of 2 or 3, and chroma of 1 to 3. It is loam. Reaction ranges from extremely acid to strongly acid.
The E horizon has hue of 5YR or 7.5YR, value of 4 to 6, and chroma of 2 or 3. Colors of 4/3 or 5/3 have value dry of 7 or more. Reaction ranges from extremely acid to strongly acid.
The Bs horizon has hue of 5YR or 7.5YR, value and chroma of 3 or 4. It is loam, sandy loam, fine sandy loam, or sandy clay loam. Reaction ranges from extremely acid to strongly acid.
Lapoin soils have a glossic horizon (2E/B or 2B/E horizon, or both). The 2E part has color like the E horizon described above. It is loam, fine sandy loam, or sandy loam. The 2Bt part has hue of 2.5YR or 5YR, value and chroma of 3 or 4. Value and chroma of 3 do not occur together. It is clay, silty clay, silty clay loam, or clay loam. Reaction ranges from strongly acid to slightly alkaline in the glossic horizon.
The 2Bt horizon has color and texture like the 2Bt part described above. Reaction ranges from moderately acid to slightly alkaline.
Some pedons have a 2Btk horizon with color and texture like the 2Bt horizon described above. Reaction is moderately or strongly alkaline.
Some pedons have a 2C horizon with color and texture like the 2Bt horizon described above. Reaction is neutral to moderately alkaline.
The 3C horizon has hue of 2.5YR or 5YR and value of 3 or 4. It is sandy loam or fine sandy loam. Reaction is neutral or slightly alkaline.
The 4R horizon (3R horizon in pedons without a 3C horizon) has hue of 5YR or 7.5YR and value of 4 or 5.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Lapoin soils are on sandstone bedrock controlled till plains. Slope gradients range from 0 to 6 percent. These soils formed in a thin mantle of loamy alluvium and in clayey till underlain by loamy till on bedrock controlled areas of till plains. Mean annual precipitation ranges from 28 to 33 inches. Mean annual air temperature ranges from 36 to 43 degrees F. The frost-free period ranges from 90 to 120 days. Elevation ranges from 600 to 1,000 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Abbaye, Brownstone, Deerton, Morganlake, Redrim, and Zeba soils. The moderately well drained Abbaye soils are nearby in landscape positions similar to Lapoin soils where there is 20 to 40 inches of loamy till over the sandstone. The excessively drained Brownstone and Deerton soils are nearby in similar landscape positions where there is 20 to 40 inches of sandy outwash over the sandstone. Morganlake soils are in similar landscape positions where there is 20 to 40 inches of sandy outwash over loamy till. The excessively drained Redrim soils are in similar landscape positions where there is 10 to 20 inches of sandy outwash over the sandstone. The somewhat poorly drained Zeba soils are nearby in slightly lower landscape positions where the soil is formed in 20 to 40 inches of loamy till over the sandstone.
DRAINAGE AND PERMEABILITY: Moderately well drained. Surface runoff is low or medium. Permeability is moderate in the loamy mantle and in the loamy substratum, slow in the clayey till, and moderately slow or moderate in the bedrock. These soils have a perched seasonal high water table at 1.0 to 2.5 feet for 1 month or more per year at some time during the period October to May in 6 or more out of 10 years.
USE AND VEGETATION: Used primarily for woodland. Native vegetation is mixed deciduous and coniferous forest. Common trees are red maple, paper birch, yellow birch, balsam fir, eastern hemlock and northern white cedar. Common understory species are mapleleaf viburnum, sweet cicely, bracken fern, large leaf aster, and Canada mayflower.
DISTRIBUTION AND EXTENT: Northern Wisconsin along Lake Superior (MLRA K92). The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota; MLRA SSO 10-4 (Duluth, Minnesota).
SERIES ESTABLISHED: Bayfield County, Wisconsin, 2004. Source of the name is the village of La Pointe on Madeline Island.
REMARKS: Diagnostic horizons and features recognized in this pedon are: ochric epipedon - 1 to 4 inches (E); albic horizon - 1 to 4 inches (E); spodic horizon - 4 to 7 inches (Bs); glossic horizon - 7 to 19 inches (2B/E); argillic horizon - 7 to 34 inches (2B/E, 2Bt1, 2Bt2); oxyaquic feature - redox accumulations and saturation below the spodic horizon and within 40 inches; lithic contact - 39 inches (4R).
Only series status, responsibility, and scrivener's errors changed - 4/09.
ADDITIONAL DATA: Soil Interpretation Record - WI0517.