LOCATION OMEGA MN+MI WIEstablished Series
TAXONOMIC CLASS: Sandy, mixed, frigid Typic Haplorthods
TYPICAL PEDON: Omega loamy sand with a convex slope of 2 percent on an outwash plain in a forest dominated by jack pine with a few aspen. (Colors are for moist soil unless otherwise stated.)
Oe--0 to 1 inch; undercomposed and partly decomposed forest litter; abrupt wavy boundary. (0 to 2 inches thick)
Oa--1 to 2 inches; black (N 2/0) muck (sapric material which is a mat of highly decomposed forest litter); weak very fine and fine granular structure; very friable; few charcoal fragments; many white and yellow fungi mycelia; many coarse roots; very strongly acid; abrupt wavy boundary. (0 to 2 inches thick)
E--2 to 3 inches; reddish gray (5YR 5/2) loamy sand, pinkish gray (5YR 7/2) dry; massive; very friable; many medium roots; sand grains uncoated; very strongly acid; abrupt wavy boundary. (1 to 4 inches thick)
Bhs--3 to 5 inches; dark reddish brown (5YR 3/3) loamy sand; weak fine subangular blocky structure; very friable; many medium roots; coatings on about all sand particles; very strongly acid; abrupt wavy boundary.
Bs--5 to 12 inches; reddish brown (5YR 4/4) loamy sand; weak fine subangular blocky structure; very friable; few fine and medium roots; coatings on about all sand particles; strongly acid; clear wavy boundary. (Combined thickness of Bs horizons is 5 to 20 inches.)
BC--12 to 24 inches; reddish brown (5YR 5/3) sand; single grain; loose; few fine roots; thin coatings on most sand particles; moderately acid; clear wavy boundary. (0 to 14 inches thick)
C--24 to 60 inches; light reddish brown (5YR 6/3) fine sand; single grain; loose; few 2 to 3 mm thick layers with lower value below 36 inches; neutral.
TYPE LOCATION: Carlton County, Minnesota; about 5 miles west and 2 miles south of Cloquet; 36 feet south and 111 feet east of the northwest corner of sec. 36, T. 49 N., R. 18 W.; USGS Topographic Quadrangle, Iverson, Minn.; Latitude 46 degrees 41 minutes 37 seconds N.; Longitude 92 degrees 34 minutes 33 seconds W.
RANGE IN CHARACTERISTICS: Depth to free carbonates is greater than 80 inches. The solum and C horizon typically do not have rock fragments, but gravel ranging from 2 to 5mm in diameter comprise as much as 10 percent of the solum and C horizon in some pedons. Mineralogy of the sand fraction is mixed, but dark colored minerals comprise 40 to 60 percent or more of that fraction. The average texture in the 10 to 40 inch particle-size control section is sand or fine sand. Horizons with texture of sand or fine sand both with more than 10 percent silt and clay or with texture of loamy sand or loamy fine sand extend to depths of 10 to 30 inches. The soil moisture control section is dry for 20 to 35 consecutive days during the 120 days following the summer solstice.
The Oe and Oa horizons are comprised of partially or well decomposed organic litter of needles, leaves and flora remains. They have hue of 10YR, value of 2 or 3, and chroma of 1 or 2, or are neutral with value of 2 and chroma of 0.
Some pedons have an A horizon as much as 3 inches thick. It has hue of 5YR to 10YR, value of 2 or 3, and chroma of 1 or 2. Some pedons have an Ap horizon with hue of 5YR to 10YR, value of 4 or 5, and chroma of 1 or 2.
The E horizon is discontinuous within the limits of some pedons, but it is present in some parts of all pedons. It has hue of 5YR to 10YR, value of 4 to 6, and chroma of 1 or 2. It is at least one unit higher in value than the B horizon immediately below it. Moist chroma of 3 is allowed if value dry is 7 or more.
The A and E horizons are loamy sand or loamy fine sand and are very strongly acid or strongly acid.
The Bhs horizon has 2.5YR or 5YR hue, value of 2 or 3, and chroma of 2 or 3. It is loamy sand, loamy fine sand, sandy loam, fine sandy loam, fine sand, or sand. It is very strongly acid or strongly acid. Sand grains have cracked coatings of iron and aluminum sesquioxides.
The Bs horizon has hue of 2.5YR or 5YR, value of 4 or 5, and chroma of 3 or 4. Texture, reaction, and coatings are like the Bhs horizon above.
When present, the Bw or BC horizons have hue of 2.5YR or 5YR, value of 4 or 5, and chroma of 4 or 5. Sand grains do not have cracked coatings. It is sand or fine sand. Reaction is moderately acid to neutral.
The C horizon has 2.5YR or 5YR hue, value of 5 or 6, and chroma of 3 to 5. It is sand or fine sand. It is moderately acid to neutral.
COMPETING SERIES: These are Adams, Furlong, Kalkaska, Liminga, and Springlake series. Adams soils are not dry for 20 or more consecutive days following the summer solstice. Furlong soils have a lithic contact within 60 inches. Kalkaska and Springlake soils have hue of 7.5YR or yellower below 30 inches or the lower one-half of the series control section. Liminga soils have 5 percent or more cemented material (ortstein) in the series control section.
GEOGRAPHIC SETTING: These soils have slightly concave to convex slopes with gradients of 0 to 25 percent on valley trains and outwash plains. They formed in thick sandy outwash sediments. These sediments are derived from the Superior or Rainy lobes of the Late Wisconsinan glaciation. Mean annual precipitation ranges from 26 to 33 inches. Mean annual air temperature ranges from 38 to 43 degrees F. Frost-free days range from 90 to 120. The elevation above sea level ranges from 800 to 1600 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: The Omega soils commonly are by far the major soil in their area of occurrence. The Nemdaji and Newson soils which formed in similar sediments are assoicated in some places. The Nemadji soils are somewhat poorly drained and the Newson soils are poorly drained. They are on lower lying terrain. Also, organic soils such as Dawson, Loxley, and Greenwood are associated in some places.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained. Surface runoff is very low to high. Permeability is rapid.
USE AND VEGETATION: Most of these soils are forested. A few areas are cleared and are cropped to forage crops or to special crops such as potatoes. Native vegetation primarily is coniferous forest. Jack pine and red pine were dominant.
DISTRIBUTION AND EXTENT: Northeastern Minnesota and northern Michigan and Wisconsin. Extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Iron County, Michigan, 1930.
REMARKS: Diagnostic horizons and soil features recognized in this pedon are: ochric epipedon - the zone from 2 to 3 inches (E horizon); albic horizon - the zone from the 2 to 3 inches (E horizon); spodic horizon - the zone from 3 to 12 inches (Bhs and Bs horizons. Note: the Soil Taxonomy Amendment Number 14 changed the criteria of spodic material. This soil now has a Bs or Bhs which meets the definition of spodic materials.)
ADDITIONAL DATA: Refer to the following publications for results of some laboratory analyses of Omega and related soils.
Pawluk, S. 1957. A study of some forest soil characteristics and their relations to jack pine growth. Ph.D. Thesis, University of Minnesota, 100 pp.
Pluth, D. J. 1965. A site evaluation for jack pine in north central Minnesota. Ph.D. Thesis, University of Minnesota, 92 pp.
Also, refer to NSSL S68MN-9-5, s68MN-9-8, and Minnesota Agricultural Experiment Station Central File Code No. 611 for results of some laboratory analyses of two additional pedons of this series. Soil Interpretation Record No. MN0170.