LOCATION ORONTO WIEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, frigid Aeric Glossaqualfs
TYPICAL PEDON: Oronto silty clay loam, on a convex, northeast facing, 3 percent slope, in an area of mixed northern hardwoods, at an elevation of about 1060 feet. (Colors are for moist soil unless otherwise noted.)
A--0 to 5 inches; dark brown (7.5YR 3/2) silty clay loam, brown (7.5YR 5/2) dry; moderate medium granular structure; friable; many fine and medium and common coarse roots; about 1 percent gravel; strongly acid; abrupt smooth boundary. (3 to 5 inches thick)
E/B--5 to 9 inches; 60 percent reddish gray (5YR 5/2) silt loam (E), pinkish gray (5YR 7/2) dry; weak medium subangular blocky structure; friable; common fine prominent strong brown (7.5YR 5/6) masses of iron accumulation; extends as tongues into and surrounds remnants of reddish brown (5YR 4/4) silty clay loam (Bt); weak medium subangular blocky structure; firm; few distinct reddish brown (2.5YR 4/4) clay films on faces of peds; common pinkish gray (5YR 7/2) dry, coatings of E material on faces of peds; many fine and medium and few coarse roots; about 2 percent gravel; moderately acid; clear wavy boundary. (0 to 10 inches thick)
B/E--9 to 15 inches; 80 percent reddish brown (5YR 4/4) silty clay loam (Bt); moderate medium subangular blocky structure; firm; common distinct reddish brown (2.5YR 4/4) clay films on faces of peds; common pinkish gray (5YR 7/2) dry, coatings of E material on faces of peds; penetrated by tongues of reddish brown (5YR 5/3) silt loam (E), pinkish gray (5YR 7/2) dry; moderate medium subangular blocky structure; firm; common fine distinct yellowish red (5YR 5/6) masses of iron accumulation; common fine and medium and few coarse roots; about 1 percent gravel; slightly acid; clear wavy boundary. (Glossic horizon - 2 to 20 inches thick)
Bt--15 to 23 inches; reddish brown (5YR 4/4) silty clay loam; moderate coarse subangular blocky structure; firm; few fine and medium roots between peds; common distinct dark reddish brown (2.5YR 3/4) clay films on faces of peds; few pinkish gray (5YR 7/2) dry, coatings of E material on faces of peds; few fine faint reddish brown (5YR 5/4) masses of iron accumulation; common prominent dark brown (7.5YR 3/2) organic coatings in root channels; about 1 percent gravel; neutral; gradual wavy boundary. (5 to 21 inches thick)
Btk1--23 to 33 inches; reddish brown (2.5YR 4/4) silty clay loam; moderate coarse prismatic structure parting to moderate medium angular blocky; firm; few fine roots between peds; common faint dark reddish brown (2.5YR 3/4) clay films on faces of peds; common prominent dark brown (7.5YR 3/2) organic coatings in root channels; few fine and medium irregular distinct light reddish brown (5YR 6/4) soft masses of calcium carbonate; slightly effervescent (1 percent calcium carbonate); about 1 percent gravel; moderately alkaline; clear wavy boundary.
Btk2--33 to 39 inches; reddish brown (2.5YR 4/4) silt loam; moderate coarse prismatic structure parting to moderate medium angular blocky; firm; few fine roots between peds; common distinct reddish brown (5YR 5/3) clay films on faces of peds; common prominent dark brown (7.5YR 3/2) organic coatings on faces of peds; common medium and coarse irregular distinct light reddish brown (5YR 6/4) soft masses of calcium carbonate; violently effervescent (16 percent calcium carbonate); about 1 percent gravel; moderately alkaline; clear wavy boundary.
Btk3--39 to 60 inches; reddish brown (2.5YR 4/4) silt loam; weak coarse prismatic structure; firm; few fine roots between peds; few distinct reddish brown (5YR 4/4) clay films on faces of peds; few prominent dark brown (7.5YR 3/2) organic coatings in root channels; common fine and medium irregular prominent pinkish gray (5YR 6/2) soft masses of calcium carbonate; violently effervescent (10 percent calcium carbonate); about 1 percent gravel; moderately alkaline; gradual wavy boundary. (Combined thickness of the Btk horizon ranges from 20 to 40 inches)
BC--60 to 80 inches; reddish brown (2.5YR 4/4) silt loam; weak coarse prismatic structure; firm; few fine roots between peds; few prominent dark brown (7.5YR 3/2) organic coatings in root channels; common medium and coarse irregular prominent pinkish gray (5YR 6/2) soft masses of calcium carbonate; violently effervescent (15 percent calcium carbonate); about 1 percent gravel; moderately alkaline.
TYPE LOCATION: Iron County, Wisconsin; about 3/4 mile west and 1 1/2 miles south of Saxon Falls; 400 feet south and 2600 feet east of the northwest corner of section 32, T. 47. N., R. 1 E.; USGS Little Girls Point, WI-MI topographic quadrangle; lat. 46 degrees 31 minutes 10 seconds N. and long. 90 degrees 23 minutes 30 seconds W.
RANGE IN CHARACTERISTICS: Depth to the base of the argillic horizon ranges from 40 to more than 60 inches. Depth to carbonates ranges from 20 to 40 inches. The weighted average clay content of the particle-size control section ranges from 22 to 35 percent and the weighted average content of fine sand or coarser is less than 15 percent. Mean annual soil temperature ranges from 38 to 45 degrees F. Volume of gravel ranges from 0 to 10 percent throughout. Volume of cobbles ranges from 0 to 2 percent throughout. Mudflow lenses or remnant discontinuous disoriented varves occur in individual horizons in some pedons. Redox features in all layers between either the lower boundary of an Ap horizon or a depth of 10 inches below the mineral soil surface (whichever is deeper) and a depth of 16 inches. Aquic conditions occur within 20 inches at some time in most years. This soil reacts positively to alpha, alpha-dipryidyl at some time during saturation.
The A horizon has hue of 5YR, 7.5YR, or 10YR, value of 2 or 3, and chroma of 1 to 3. Cultivated pedons have an Ap horizon with hue of 5YR, 7.5YR, or 10YR, value of 3 or 4, and chroma of 3 or 3. Reaction naturally ranges from very strongly acid or slightly acid but ranges to neutral, where the soil is limed.
Some pedons have an E horizon with 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. The E horizon is silt loam. Reaction ranges from very strongly acid to moderately acid.
Oronto soils have a glossic horizon (E/B or B/E horizon or both). The E part has color and texture like the E horizon described above. The Bt part has hue of 2.5YR, or 5YR, value of 4 or 5, and chroma 3 or 4. It is typically silty clay loam or clay loam but in some pedons it is silt loam. Reaction ranges from very strongly acid to slightly acid.
The Bt horizon has hue of 2.5YR or 5YR, and value of 3 or 4. It is typically silty clay loam or clay loam but, in some pedons, it is silt loam. Reaction ranges from strongly acid to slightly alkaline.
The Btk horizon has hue of 2.5YR or 5YR, and value of 4 or 5. It is typically silty clay loam or clay loam grading to silt loam in the lower part. Reaction is moderately alkaline or strongly alkaline.
The BC horizon has hue of 2.5YR or 5YR, and value of 4 or 5. It is silt loam, silty clay loam or clay loam. Reaction is moderately alkaline or strong alkaline.
Some pedons have a C horizon with color, texture and reaction like the BC horizon described above.
COMPETING SERIES: There are no competing series. Related soils are the Badriver and Gichigami series. Badriver soils have fine particle-size class. Gichigami soils are Oxyaquic Glossoboralfs.
GEOGRAPHIC SETTING: Oronto soils are on flats and in drainageways and depressions on till plains. Slope gradients range from 0 to 3 percent. These soils formed in silty and loamy till derived from silty and loamy lacustrine deposits. 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 1200 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bohemian, Brimley, Bruce, Denomie, and Gichigami soils. The well drained Bohemian soils, the somewhat poorly drained Brimley soils, and the poorly drained Bruce soils form a drainage sequence in nearby areas where the soil formed in stratified lacustrine deposits. The well drained Denomie soils and the moderately well drained Gichigami soils form a drainage sequence with Oronto soils.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Runoff is slow. Permeability is moderately slow or moderate. Oronto soils have a perched seasonal high water table at depth of 0.5 to 2.0 feet for much of the time during the period September to June in most years.
USE AND VEGETATION: Most areas are used for woodland. Some areas are used for cropland or pastureland. Oats, bromegrass, timothy, reed canarygrass, and alfalfa are the principal crops. Many areas which were formally cropland are now idle and are reverting to natural vegetation. Native vegetation is mixed deciduous and coniferous forest. Common trees are red maple, balsam fir, quaking aspen, paper birch, and willow. Common understory species are speckled alder, redosier dogwood, black snakeroot, wild sarsaparilla, and bracken fern.
DISTRIBUTION AND EXTENT: Northern Wisconsin along Lake Superior (MLRA K92). This series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota; MLRA SSO 10-8 (Marquette, Michigan).
SERIES ESTABLISHED: Iron County, Wisconsin, 2006. Source of the name is Oronto Creek in Northeastern Iron County.
REMARKS: Diagnostic horizons and features recognized in this pedon: ochric epipedon--0 to 5 inches (A); glossic horizon--5 to 15 inches (E/B, B/E); argillic horizon--9 to 60 inches (B/E, Bt, Btk1, Btk2, Btk3); aquic feature--redox features in all layers between 10 and 16 inches and aquic conditions within 20 inches for some time in most years.
Only series status, responsibility, and scrivener's errors changed - 4/09.
ADDITIONAL DATA: Soil Interpretation Record - WI0573. Refer to soil survey sample number S90WI-051-004 for NSSL data on the typical pedon. Refer to soil survey sample number S87WI-003-002 for NSSL data on another Oronto pedon.