LOCATION ROCKMILL OH+IN
Established Series
Rev. JRS-RJG-JWH-SJH
11/2021
ROCKMILL SERIES
The Rockmill series consists of very deep, very poorly drained soils formed in alluvium and the underlying organic soil material on flood plains or in depressional areas on till plains. Slope ranges from 0 to 3 percent. Mean annual precipitation is about 914 mm (36 inches), and mean annual air temperature is 11 degrees C (51 degrees F).
TAXONOMIC CLASS: Fine-silty, mixed, superactive, nonacid, mesic Thapto-histic Fluvaquents
TYPICAL PEDON: Rockmill silty clay loam, on a 1 percent slope in a cultivated field at an elevation of 246 meters (808 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 33 cm (0 to 13 inches); dark grayish brown (10YR 4/2) silty clay loam, gray (10YR 5/1) dry; weak coarse granular structure; friable; many fine and medium roots; moderately acid; abrupt smooth boundary. [30 to 38 cm (12 to 15 inches) thick]
Bg--33 to 46 cm (13 to 18 inches); grayish brown (10YR 5/2) silty clay loam; moderate fine subangular blocky structure; friable; common fine roots; black (10YR 2/1) and very dark grayish brown (10YR 3/2) organic coatings on faces of peds; moderately acid; abrupt wavy boundary. [10 to 63 cm (4 to 25 inches) thick]
0a1--46 to 58 cm (18 to 23 inches); black (10YR 2/1) broken face and rubbed muck (sapric material); 5 percent fiber when broken, 0 percent rubbed; moderate coarse prismatic structure parting to weak medium platy; friable; few fine roots; gray (10YR 5/1) coatings and fillings of mineral soil on vertical surfaces; moderately acid; clear smooth boundary.
0a2--58 to 102 cm (23 to 40 inches); black (10YR 2/1) broken face and rubbed muck (sapric material); 10 percent fiber when broken, 5 percent rubbed; moderate coarse prismatic structure parting to moderate medium platy; friable; few fine roots; strongly acid; clear smooth boundary.
0a3--102 to 203 cm (40 to 80 inches); very dark brown (10YR 2/2) broken face and rubbed muck (sapric material); 50 percent fiber when broken, 20 percent rubbed; moderate medium platy structure; very friable; moderately acid.
TYPE LOCATION: Fairfield County, Ohio; l mile southwest of Pickerington, in Violet Township; 1,225 feet north and 750 feet east of southwest corner of sec. 16, T. 15 N., R. 20 W.; USGS Canal Winchester, Ohio topographic quadrangle; lat. 39 degrees 52 minutes 25 seconds N. and long. 82 degrees 46 minutes 39 seconds W., NAD 27.
RANGE IN CHARACTERISTICS:
Depth to the base of the mineral soil: 41 to 102 cm (16 to 40 inches)
Depth to bedrock: greater than 203 cm (80 inches)
Rock fragments: lacking in most pedons but some pedons contain up to 10 percent rock fragments, mostly fine gravel in the mineral horizons
Ap horizon:
Hue: 10YR or 2.5Y
Value: 2 to 4
Chroma: 1 or 2
Texture: silty clay loam or silt loam or the mucky analogs of these textures
Reaction: strongly acid to slightly alkaline
Bg horizon:
Hue: 10YR to 5Y
Value: 3 to 5
Chroma: 1 or 2
Texture: silt loam or silty clay loam or the mucky analogs of these textures
Reaction: strongly acid to slightly alkaline
Some pedons have a Cg horizon.
Some pedons have an Ab horizon.
Oa horizon:
Hue: 5YR to 2.5Y, or is neutral
Value: 2, 2.5 or 3
Chroma: 0 to 2
Texture: muck (sapric material) and includes either woody or herbaceous plant material, or both
Reaction: strongly acid to slightly alkaline
COMPETING SERIES: This is the
Snohomish series. Snohomish soils have 15 to 60 percent volcanic ash in the overlying alluvium.
GEOGRAPHIC SETTING: Rockmill soils are on flood plains or in depressional areas on till plains. Slope ranges from 0 to 3 percent. The soils formed in alluvium and the underlying organic soil material. Climate is humid and temperate. Mean annual precipitation ranges from 889 to 1143 mm (35 to 45 inches). Mean annual air temperature ranges from 7 to 12 degrees C (45 to 53 degrees F). Frost-free period is 130 to 178 days. Elevation is 238 to 250 meters (780 to 820 feet) above mean sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Algiers,
Carlisle,
Muskego, and
Sloan soils. The somewhat poorly drained Algiers soils formed entirely in mineral deposits on flood plains. The very poorly drained Carlisle and Muskego soils formed in organic deposits on depressions. The very poorly drained Sloan soils formed in mineral deposits on floodplains.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Very poorly drained. The depth to the top of an intermittent apparent high water table ranges from 15 cm (0.5 foot) above the surface to 30 cm (1.0 foot) below the surface between September and June in normal years. The potential for surface runoff is negligible. Saturated hydraulic conductivity is moderately high in the mineral part and high or very high in the organic part. Permeability is moderate in the mineral part and moderately rapid or rapid in the organic part. Flooding and ponding is common for brief periods from September through June.
USE AND VEGETATION: Rockmill soils are cultivated where drainage is established. Principal crops are vegetables, corn and soybeans. Partially drained areas are used for hay and pasture. Wooded areas have elm, red maple, and other water-tolerant species.
DISTRIBUTION AND EXTENT: South Central Ohio; MLRA 111E. The series is of small extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: AMHERST, MASSACHUSETTS
SERIES ESTABLISHED: Fairfield County, Ohio, 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: from the surface to a depth of 33 cm (Ap horizon).
Histic epipedon (buried): from a depth of 46 to 203 cm (Oa horizon).
Thapto-Histic subgroup: buried histic epipedon at 46 cm (0a horizon).
Fluvaquents great group: irregular decrease in organic carbon with depth and more than 0.2 organic carbon at 127 cm (50 inches), and other features recognized for Aquents.
This soil was previously mapped as Wallkill and Wakeena series.
ADDITIONAL DATA: Characterization data for this soil, typical pedon FA-35, is available from the Soil Characterization Laboratory, at The Ohio State University, Columbus, OH.
National Cooperative Soil Survey
U.S.A.