LOCATION GRINDSTONE MIEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Glossaquic Hapludalfs
TYPICAL PEDON: Grindstone loam - on a nearly level area of 1 percent slope on till plain cropped to alfalfa hay. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 9 inches; dark grayish brown (10YR 4/2) loam, light brownish gray (10YR 6/2) dry; moderate fine granular structure; friable; common fine roots; 2 percent gravel and cobbles; neutral; abrupt smooth boundary. (5 to 10 inches thick)
B/E--9 to 11 inches; yellowish brown (10YR 5/4) clay loam (B); pale brown (10YR 6/3) sandy loam (E) occurs as coatings on the faces of peds; common fine prominent strong brown (7.5YR 5/8) mottles; weak medium subangular blocky structure; friable; few fine roots; 2 percent gravel and cobbles; slightly alkaline; abrupt irregular boundary. (2 to 8 inches thick)
Bt--11 to 20 inches; brown (10YR 5/3) clay loam; few fine faint grayish brown (10YR 5/2) and common fine prominent yellowish brown (10YR 5/6) mottles in lower part of horizon; weak medium prismatic structure parting to moderate medium angular blocky; firm; few fine roots; thin continuous dark brown (10YR 4/3) clay films on vertical faces of peds and thin patchy clay films on horizontal faces; 2 percent gravel and cobbles; slightly alkaline; clear wavy boundary. (5 to 12 inches thick)
BC--20 to 27 inches; light yellowish brown (10YR 6/4) silt loam; few fine distinct yellowish brown (10YR 5/6) and common medium prominent gray (10YR 6/1) mottles; weak fine subangular blocky structure; friable; few fine roots; 3 percent gravel and cobbles; strongly effervescent; moderately alkaline; clear wavy boundary. (0 to 10 inches thick)
Cd1--27 to 55 inches; brown (10YR 5/3) loam; strong thick platy structure; very firm; 4 percent gravel and cobbles; strongly effervescent; moderately alkaline; gradual wavy boundary.
Cd2--55 to 70 inches; brown (10YR 5/3) loam; few fine prominent yellowish brown (10YR 5/6) mottles; moderate thick platy structure; very firm; 4 percent gravel and cobbles; strongly effervescent; moderately alkaline.
TYPE LOCATION: Huron County, Michigan, about 1/2 mile south of the town of Port Austin, 1,210 feet north and 1,180 feet west of the center, sec. 32, T. 19 N., R. 13 E.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 12 to 33 inches. Depth to carbonates ranges from 12 to 25 inches. The depth to very firm dense till ranges from 24 to 40 inches. The reaction of the Ap and B horizons are neutral or slighly alkaline. Gravel content ranges from 2 to 15 percent throughout the pedon. Cobble content ranges from 0 to 25 percent in the A horizon and from 0 to 8 percent in the rest of the pedon.
The Ap horizon has 10YR or 7.5YR hue; value of 3 or 4, and chroma of 2 or 3. It is loam, cobbly loam or sandy loam. The E material has 10YR hue, value of 6 or 7, and chroma of 2 or 3. It is sandy loam or loam and occurs as coatings on the peds of the B/E horizon.
The Bt horizon has 10YR or 7.5YR hue, value of 3 to 6, and chromas of 2 or 4. Texture is silt loam, clay loam, or loam.
The Cd horizons have 10YR hue; values of 4 to 6, and chromas of 3 or 4. Consistence is very firm or extremely firm. Vertical or oblique fracture planes are observable in the Cd horizons in an exposed cut. The faces of the fractures are light gray (10YR 7/1). Immediately below the faces of the fractures the color is yellowish brown (10YR 5/6). The fracture planes are at intervals of 12 to 36 inches. Any root penetration of the Cd horizon occurs along these fractures.
COMPETING SERIES: These are the Aurora, Danley, Nessel, Nunda, and Vlasaty series in the same family. All of these lack the very firm or extremely firm compact till above 40 inches. In addition, the Aurora soils have shale bedrock above 40 inches.
GEOGRAPHIC SETTING: Grindstone soils are on nearly level and gently sloping areas of till plains and moraines. Slopes are commonly 0 to 2 percent but range to 6 percent. The soils formed in calcareous, loamy glacial till of Wisconsinan Age. Mean annual temperature ranges from 45 to 50 degrees F, and the mean annual precipitation is 29 to 37 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: Grindstone soils are part of a drainage sequence which includes the somewhat poorly drained Shebeon soils and the poorly drained Kilmanagh soils. Badaxe soils are associated in some places where a thin sandy loam layer overlies the loam till.
DRAINAGE AND PERMEABILITY: Moderately well drained. Surface runoff is slow or medium. Permeability is moderate in the solum and very slow in the Cd horizon.
USE AND VEGETATION: Most of these soils are cultivated. Corn, soybeans, small grains and legume hay are the principal crops.
DISTRIBUTION AND EXTENT: Thumb area of lower Michigan. The series is moderately extensive with a total of roughly 15,000 acres.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Huron County, Michigan; 1978.
REMARKS: See S74MI-63-3. Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface to 9 inches (Ap horizon); argillic horizon - the zone from 9 to 20 inches (B part of B/E horizon and Bt horizon).