LOCATION IRONMOUND OKEstablished Series
TAXONOMIC CLASS: Loamy, mixed, active, thermic, shallow Udic Haplustepts
TYPICAL PEDON: Ironmound loam, rangeland: (Colors are for dry soil unless otherwise stated).
A--0 to 7 inches; reddish brown (5YR 4/4) loam, dark reddish brown (5YR 3/4) moist; moderate medium subangular blocky structure parting to moderate medium granular; hard, friable; many very fine and fine roots; common very fine and fine pores; slightly acid; clear smooth boundary. (4 to 8 inches thick).
Bw--7 to 16 inches; red (2.5YR 4/6) loam, dark red (2.5YR 3/6) moist; moderate medium subangular blocky structure; hard, friable; common very fine and fine roots; common very fine and fine pores; neutral; clear smooth boundary. (5 to 14 inches thick).
Cr--16 to 40 inches; red (2.5YR 4/6) weathered sandstone, dark red (2.5YR 3/6) moist; neutral.
TYPE LOCATION: Logan County, Oklahoma; 1 mile west and 2 miles north of Lovell; 500 feet west and 1300 feet north of the southeast corner of Sec. 30, T. 19 N., R. 4 W.
RANGE IN CHARACTERISTICS: Solum thickness and depth to bedrock is 10 to 20 inches.
The A horizon has a hue of 2.5YR or 5YR, value of 4 or 5, and chroma of 2 to 6. Texture is loam silt loam, very fine sandy loam, or fine sandy loam. Reaction ranges from moderately acid to moderately alkaline. Content of coarse fragments of sandstone less than 76 mm in diameter range from 0 to 10 percent by volume.
The Bw horizon has a hue of 10R to 5YR, value of 4 or 5, and chroma of 4 to 6. Texture is loam or fine sandy loam. Reaction ranges from slightly acid to moderately alkaline. Content of coarse fragments of sandstone less than 76 mm in diameter range from 0 to 10 percent by volume.
The Cr horizon has a hue of 10R to 5YR, value of 4 to 6, and chroma of 4 to 8. It is weathered sandstone or shale, or, sandstone interbedded with siltstone or shale. The upper part is usually highly fractured and spacing of cracks is less than 10 cm apart. The lower part of the Cr horizon has fractures greater than 10 cm apart. This material has high or very high excavation difficulty. Most of this material slakes in water or sodium hexametaphosphate within 15 hours. Reaction ranges from neutral to moderately alkaline and may be calcareous in some pedons.
COMPETING SERIES: There are no competing series in this family. Soils in similar families are Darnell, Dill, Loco, and Lucien. Darnell soils have siliceous mineralogy. Dill soils have a coarse-loamy textural control section. Loco and Lucien soils have mollic epipedons.
GEOGRAPHIC SETTING: Ironmound soils are very gently sloping to steep upland soils on convex ridge crests and back slopes in the Central Rolling Red Prairies. Slopes range from 1 to 40 percent. They formed in material weathered from sandstone interbedded with siltstone or sandy shale of Permian age.
Mean Annual Precipitation: 26 to 38 inches.
Mean Annual Temperature: 58 to 63 degrees F.
Thornthwaite Annual P-E indices: 44 to 64.
Frost Free Days: 200 to 230.
Elevation: 700 to 1500 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coyle, Grainola, Kingfisher, Masham, Piedmont, and Zaneis soils. Coyle, Grainola, Kingfisher, Piedmont, and Zaneis soils have a solum greater than 20 inches thick. In addition Coyle, Grainola, Kingfisher, Piedmont, and Zaneis soils have Bt horizons. In addition Grainola, Masham, and Piedmont soils have a fine textured control section. Coyle and Kingfisher soils are on similar landscapes. Grainola, Masham, and Piedmont soils are on lower back slopes. Zaneis soils are on higher ridge crests and upper back slopes.
DRAINAGE AND PERMEABILITY: Well drained; moderately rapidly permeable; runoff is negligible on 1 to 3 percent slopes, very low on 3 to 5 percent slopes, low on 5 to 10 percent slopes, medium on 10 to 20 percent slopes and high on slopes greater than 20 percent.
USE AND VEGETATION: The principle use is for rangeland. Some of the less sloping areas are cultivated to small grains or tame pasture. Native vegetation consists of short to tall prairie grasses.
DISTRIBUTION AND EXTENT: Central Rolling Red Prairies of Oklahoma, Kansas, and Texas. The soil is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Logan County, Oklahoma; 1994.
REMARKS: These soils were formerly mapped as Lucien.
Diagnostic horizons and features in this pedon are:
Ochric epipedon: The zone from the surface of the soil to a depth of 7 inches (A horizon).
Cambic horizon: The zone from 7 inches to a depth of 16 inches (the Bw horizon).
Paralithic contact: at a depth of 16 inches (ranges from 10 to 20 inches). This material visually appears to be root restrictive.
Soil Interpretation Record: OK0387 - Ironmound
OK0409 - Ironmound, eroded