LOCATION TWINMOUND WIEstablished Series
TAXONOMIC CLASS: Frigid, uncoated Typic Quartzipsamments
TYPICAL PEDON: Twinmound sand - on a south facing, convex 34 percent slope in a grazed woodland at an elevation of 1140 feet. (Colors are for moist soils unless otherwise stated.)
Oi--0 to 1 inches; dark grayish brown (10YR 4/2) peat (fibric material which is a mat of partially decomposed forest litter); about 90 percent fiber and 75 percent rubbed; weak thin platy structure; very friable; extremely acid; abrupt smooth boundary. (0 to 3 inches thick)
A--1 to 3 inches; very dark brown (10YR 2/2) fine sand; dark grayish brown (10YR 4/2) dry; weak fine subangular blocky structure; very friable; many very fine and fine and few medium and coarse roots; common very pale brown (10YR 8/2) uncoated sand grains; very strongly acid; abrupt smooth boundary. (1 to 5 inches thick)
Bw1--3 to 10 inches; yellowish brown (10YR 5/6) fine sand; weak medium subangular blocky structure; very friable; many very fine and fine and few medium and coarse roots; about 5 percent sandstone channers; strongly acid; abrupt wavy boundary.
Bw2--10 to 17 inches; yellowish brown (10YR 5/8) fine sand; weak coarse subangular blocky structure; very friable; many very fine and fine and few medium roots; about 10 percent sandstone channers; strongly acid; gradual smooth boundary. (Combined thickness of the Bw horizons ranges from 10 to 35 inches.)
BC--17 to 26 inches; brownish yellow (10YR 6/8) channery fine sand; single grain; loose; many very fine and fine roots; about 20 percent sandstone channers; strongly acid; abrupt wavy boundary. (0 to 15 inches thick)
Cr--26 to 60 inches; dark yellowish brown (10YR 4/6) sandstone.
TYPE LOCATION: Dunn County, Wisconsin; about 2.25 miles south and 2 miles west of Sand Creek; 2100 feet south and 560 feet east of the northwest corner of sec. 34, T. 31 N., R. 11 W.; USGS Sand Creek, WI quad.; lat.- 45 degrees, 7', 56" N; long.- 91 degrees, 43', 35" W.
RANGE IN CHARACTERISTICS: Thickness of the solum and depth to the paralithic contact with weakly cemented sandstone range from 20 to 40 inches. Reaction ranges from extremely acid to neutral in the solum. Volume of sandstone channers ranges from 0 to 35 percent throughout.
The A horizon has hue of 7.5YR or 10YR, value of 2 to 4, and chroma of 1 to 3. It is fine sand or sand.
Some pedons have an E horizon with hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 1 to 3. It is fine sand or sand or the channery analogs.
The Bw horizon has hue of 7.5YR or 10YR and value of 3 to 6, and chroma of 4 to 6. Bw horizons with spodic colors have less than 0.6 percent organic carbon. The Bw is fine sand or sand or the channery analogs.
The BC horizon has hue of 7.5YR, 10YR, or 2.5Y; value of 5 or 6; and chroma of 3 to 8; or, value of 7 or 8; and chroma of 2 to 8. It is fine sand or sand or the channery analogs.
The Cr horizon has color like the BC horizon described above.
COMPETING SERIES: These are the Shelldrake and Simescreek series. Similar soils are the Arbutus, Boone, Ludington, and Plainbo series. Shelldrake and Simescreek soils do not have a paralithic contact within 60 inches. Arbutus soils have a lithic contact of igneous or metamorphic bedrock at a depth of 20 to 40 inches. Boone soils are mesic. Ludington soils have a spodic horizon. Plainbo soils have mixed mineralogy.
GEOGRAPHIC SETTING: Twinmound soils are on summits, shoulders, and back slopes of hills on bedrock controlled uplands. Slopes range from 6 to 50 percent. These soils formed in siliceous sandy residuum from the underlying sandstone or in siliceous sandy colluvium, or both. Mean annual precipitation ranges from 28 to 33 inches. Mean annual temperature ranges from 39 to 45 degrees F. The frost free period rages from about 120 to 135 days. Elevation ranges from 800 t0 1400 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dobie and Hayriver series. The well drained Dobie soils are on summits and shoulders at slightly higher elevations than Twinmound soils where there is a 20 to 40 inch thick loess mantle over glauconitic sandstone. The well drained Hayriver soils are on landscape positions similar to those of Twinmound soils where there is 20 to 40 inches of loamy residuum over glauconitic sandstone.
DRAINAGE AND PERMEABILITY: Excessively drained. Surface runoff is moderate to very rapid. Permeability is rapid.
USE AND VEGETATION: Most areas of this soil are in woodland. Native vegetation is deciduous forest with some conifers. Common trees are northern pin oak, northern red oak, white oak, red maple, and paper birch with a few eastern white pine in some places.
DISTRIBUTION AND EXTENT: Northwestern Wisconsin. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Barron County, Wisconsin, 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon: ochric epipedon - from 0 to 2 inches (A); features - have less than 10 percent of weatherable minerals in the control section; have less than 5 percent silt plus clay in the control section (uncoated); paralithic contact - 26 inches (2Cr).
ADDITIONAL DATA: Soil Interpretation Record - WI0430. Refer to soil survey sample number S93WI-033-001 for NSSL data on the typical pedon.