LOCATION RIVERDALE MI+INEstablished Series
TAXONOMIC CLASS: Loamy, mixed, semiactive, mesic Aquic Arenic Hapludalfs
TYPICAL PEDON: Riverdale loamy sand - on a north-facing slope of 1 percent in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; very dark grayish brown (10YR 3/2) loamy sand; grayish brown (10YR 5/2) dry; weak fine granular structure; very friable; common fine roots; about 11 percent gravel; abrupt smooth boundary. (6 to 10 inches thick)
Bw1--8 to 14 inches; strong brown (7.5YR 5/6) loamy sand; few fine prominent yellowish brown (10YR 6/4) mottles; weak fine subangular blocky structure; very friable; few fine roots; about 8 percent gravel; slightly acid; clear wavy boundary.
Bw2--14 to 28 inches; pale brown (10YR 6/3) sand; common medium faint grayish brown (10YR 5/2) and few fine distinct yellowish brown (10YR 5/6) mottles; single grain; loose; few fine roots; about 10 percent gravel; neutral; clear wavy boundary. (The combined thickness of the Bw horizon is 10 to 24 inches.)
Bt--28 to 33 inches; yellowish brown (10YR 5/6) gravelly sandy loam; common medium distinct grayish brown (10YR 5/2) mottles; weak medium subangular blocky structure; friable; few fine roots; few faint clay films on faces of peds and in pores; about 20 percent gravel; neutral; gradual wavy boundary. (4 to 12 inches thick)
2C--33 to 60 inches; grayish brown (10YR 5/2) gravelly sand; single grained; loose; about 25 percent gravel and 1 percent cobbles; strong effervescence; moderately alkaline.
TYPE LOCATION: Gratiot County, Michigan; about 1 mile west and 1 mile north of Forest Hill; 1,900 feet west and 40 feet north of the southeast corner of sec. 6, T. 12 N., R. 3 W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 24 to 40 inches and corresponds to depth of free carbonates. Gravel content ranges from 2 to 25 percent in the solum and from 20 to 50 percent in the 2C horizon. The solum ranges from slightly acid to mildly alkaline.
The Ap horizon has hue of 10YR, value of 2 to 4, and chroma of 1 to 3. It is sand, loamy sand, or sandy loam. Uncultivated areas have an A horizon with similar colors and textures. Where present, the E horizon has hue of 10YR, value of 5 or 6, and chroma of 2 or 3. Textures are the same as that for the A horizons.
The Bw horizon has hue of 10YR or 7.5YR, value of 5 or 6, and chroma of 3 to 6. It is sand or loamy sand.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 4 to 6. It is gravelly sandy loam or sandy loam, but has thin layers of loamy sand in some pedons.
The 2C horizon has hue of 10YR, value of 5 to 7, and chroma of 2 or 3. It is gravelly sand, very gravelly sand, or stratified sand and gravel.
COMPETING SERIES: These are the Bixler, Branch, Leola, Markton, Rimer, and Selfridge series in the same family. Bixler soils have strata of loam and silt loam in the Bt and 2C horizons. Branch soils have thicker argillic horizons and a thicker sola. Leola soils have sand in the lower part of the solum and substratum and do not have gravel in the pedon. Markton soils have loam 2B and 2C horizons. Rimer and Selfridge soils have clayey and loamy 2C horizons.
GEOGRAPHIC SETTING: Riverdale soils are on outwash plains, lake plains, valley trains, deltas, and low beach ridges. Slope gradients range from 0 to 6 percent. They formed in sandy glacial drift of Wisconsinan age. Mean annual precipitation ranges from 38 to 34 inches, and mean annual temperature from 46 to 50 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gilford, Kingsville, and Vestaburg soils in wet depressions within areas of Riverdale soils. Gilford soils have mollic epipedons. Kingsville soils do not have rock fragments. Vestaburg soils have mollic epipedons and do not have argillic horizons.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Surface runoff is slow. Permeability is moderately rapid in the A and B horizons and very rapid in the underlying gravelly sand.
USE AND VEGETATION: Soils are cultivated in most areas. Corn, soybeans, and small grain are the principal crops. Soils are used for woodland and pasture in some areas. The native vegetation was hardwoods, principally American elm, white ash, hickory, and swamp white oak.
DISTRIBUTION AND EXTENT: Southern Lower Michigan and northern Indiana. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Gratiot County, Michigan, 1975.
REMARKS: Diagnostic horizons and other features recognized in this pedon are: ochric epipedon - the zone from the surface to 8 inches (Ap horizon); argillic horizon - the zone from 28 to 33 inches (Bt horizon); aquic feature - mottles with chroma of 2 in the upper 10 inches of the argillic horizon; arenic feature - textures coarser than loamy fine sand within 20 inches of the surface.