LOCATION MARCUS IA+MNEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Endoaquolls
TYPICAL PEDON: Marcus silty clay loam with a slope of about 1 percent - cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 10 inches; black (N 2/0) silty clay loam; very dark gray (10YR 3/1) dry; weak fine subangular blocky structure parting to moderate medium and fine granular; friable; neutral; abrupt smooth boundary.
A1--10 to 15 inches; black (10YR 2/1) silty clay loam; very dark gray (10YR 3/1) dry; weak fine subangular blocky structure; friable; few black (10YR 2/1) concretions (manganese oxides); slightly acid; gradual smooth boundary.
A2--15 to 19 inches; black (10YR 2/1) silty clay loam; dark gray (10YR 4/1) dry; weak fine subangular blocky structure parting to weak fine granular; friable; few black (10YR 2/1) concretions (manganese oxides); common fine distinct very dark grayish brown (2.5Y 3/2) and few fine distinct dark grayish brown (2.5Y 4/2) redox depletions; neutral; clear smooth boundary. (Combined thickness of the A horizons is 15 to 24 inches.)
Bg1--19 to 24 inches; olive gray (5Y 4/2) silty clay loam; weak fine subangular structure; friable; black (10YR 2/1) on surfaces along pores and root channels; few strong brown (7.5YR 5/8) and black (10YR 2/1) concretions (iron and manganese oxides); few fine prominent yellowish brown (10YR 5/6) redox concentrations; common medium faint dark gray (5Y 4/1) redox depletions; neutral; gradual smooth boundary.
Bg2--24 to 31 inches; olive gray (5Y 4/2) silty clay loam; moderate medium and fine subangular blocky structure; friable; some black (10YR 2/1) on surfaces along pores and root channels; common strong brown (7.5YR 5/8) and black (10YR 2/1) concretions (iron and manganese oxides); common fine prominent yellowish brown (10YR 5/6) redox concentrations; common medium faint dark gray (5Y 4/1) redox depletions; slightly alkaline; gradual smooth boundary.
Bg3--31 to 40 inches; olive gray (5Y 5/2) silty clay loam; moderate medium and fine subangular blocky structure; friable; common strong brown (7.5YR 5/8) and black (10YR 2/1) accumulations (iron and manganese oxides); common fine prominent strong brown (7.5YR 5/6) redox concentrations; common medium faint gray (5Y 5/1) redox depletions; slightly alkaline; gradual smooth boundary. (Combined thickness of the Bg horizons is 15 to 30 inches.)
BCg--40 to 46 inches; olive gray (5Y 5/2) silty clay loam; weak medium subangular blocky structure; friable; common strong brown (7.5YR 5/8) and black (10YR 2/1) accumulations (iron and manganese oxides); common medium prominent strong brown (7.5YR 5/6) redox concentrations; slightly alkaline; clear smooth boundary.
Cg--46 to 60 inches; olive gray (5Y 5/2) and light olive gray (5Y 6/2) silt loam; massive; friable; common strong brown (7.5YR 5/8) and black (10YR 2/1) concretions (iron and manganese oxides); common very pale brown (10YR 8/2) calcium carbonate accumulations and few very pale brown (10YR 8/2) calcium carbonate nodules; many medium prominent yellowish brown (10YR 5/6) and strong brown (7.5YR 5/8) redox concentrations; strongly effervescent; moderately alkaline.
TYPE LOCATION: Cherokee County, Iowa; about 4 miles north and 1/2 mile west of Marcus; about 1860 feet west and 310 feet north of the southeast corner of sec. 9, T. 93 N., R. 42 W; USGS Granville East, Iowa topographic quadrangle, latitude 42 degrees 52 minutes 53 seconds N., longitude 95 degrees 48 minutes 24 seconds W., NAD27.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon: 12 to 24 inches
Depth to glacial till: greater than 60 inches
Depth to free carbonates: 24 to 48 inches
The particle size control section averages between 30 to 35 percent clay. Clay content decreases regularly through the B horizon and into the C horizon.
A horizon:
Hue: 10YR, 2.5Y or Neutral
Value: 2 or 3
Chroma: 0 or 1
Texture: silty clay loam or silty clay
Reaction: slightly acid to slightly alkaline
Clay content: 36 to 42 percent
An AB horizon is in some pedons.
Bg horizon:
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2
Texture: silty clay loam or silty clay
Reaction: slightly acid to moderately alkaline
Cg horizon:
Hue: 2.5Y or 5Y
Value: 5 or 6
Chroma: 1 or 2
Texture: silt loam
2Cg horizon (below depths of 60 inches in some pedons):
Hue: 2.5Y or 5Y
Value: 5 or 6
Chroma: 1 or 2
Texture: loam or clay loam
Reaction: slightly alkaline or moderately alkaline
Rock fragment content: 1 to 8 percent by volume
Moist bulk density: 1.6 to 1.8 g/cc
COMPETING SERIES:
Chalmers soils formed in less than 40 inches of loess and have a higher sand content in the lower B horizon.
Dolbee soils formed in alluvium, have less clay in the upper part of the solum, and are deeper to carbonates.
Drummer soils have less clay in the A horizon and contain more sand in the lower part of the B horizon and have C horizons of stratified outwash and glacial drift.
Elvira soils formed in alluvium, have about 5 percent less clay in the solum, have more free iron, and have a stratified C horizon.
Garwin soils commonly have slightly less clay in the A horizon and upper few inches of the B horizon, are somewhat more acid, are deeper to free carbonates and have somewhat more annual precipitation.
Gillett Grove (T) soils formed in 40 to 60 inches of loess and have a lithologic discontinuity in the lower two thirds of the series control section.
Hartsburg soils have free carbonates at depths as shallow as 15 inches and have less clay in the A horizon and upper few inches of the B horizon.
Leshara,
Madelia, and
Ossian soils have less than 30 percent clay in the 10- to 40-inch control section as well as in the A horizon.
Maxcreek,
Maxfield, and
Rushmore soils contain more sand in the lower part of the B horizon and have C horizons of loam glacial till.
Patton soils have somewhat less clay in the A horizon and upper few inches of the B horizon and C horizons of stratified silt loam and silty clay loam alluvium.
Pella soils have free carbonates at depths as shallow as 15 inches, have more sand in the lower part of the B horizon and C horizon and are stratified in the C horizon.
Sable soils have less clay in the A horizon and upper part of the B horizon.
Wacousta soils have thinner sola and free carbonates at depths of 14 to 20 inches.
GEOGRAPHIC SETTING:
Landscape: nearly level uplands
Slope: 0 to 2 percent
Parent Material: loess
Mean annual air temperature: about 45 to 48 degrees F
Mean annual precipitation: about 26 to 28 inches
GEOGRAPHICALLY ASSOCIATED SOILS:
Galva soils are well drained and form a drainage sequence with the Marcus soils.
Primghar soils are somewhat poorly drained form a drainage sequence with the Marcus soils.
Sac soils have higher chromas in the B horizon and clay loam till about 30 inches.
Galva, Primghar, and Sac soils occupy positions upslope from the Marcus soils.
Afton soils are downslope in drainageways.
DRAINAGE AND PERMEABILITY:
Drainage: poorly drained or very poorly drained -- seasonal high saturation occurs at the surface to 1 foot below the surface during the wettest period of normal years.
Permeability: moderately slow
Surface runoff: low to negligible
USE AND VEGETATION: Largely used for corn and soybeans; small grain and legume hay are also grown. Native vegetation is principally tall grasses and some sedges.
DISTRIBUTION AND EXTENT: Northwest Iowa and southwestern Minnesota. Marcus soils are of large extent.
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Cherokee County, Iowa, 1924.
REMARKS: Available laboratory data indicate Marcus soils are marginal to the fine family as defined in Soil Taxonomy. Lab data for typical pedon is available from Iowa State University (lab # 35415-23). Very poorly drained was added to drainage class for Clay County, Iowa (12/18/01).
The type location was moved from Clay County, Iowa as it had till above depths of 60 inches. The Gillett Grove series was set up have have till at depths of 40 to 60 inches.