LOCATION DEARBORN INEstablished Series
The Dearborn series consists of very deep, well drained, soils formed in loamy alluvium. Slopes range from 0 to 2 percent. Mean annual precipitation is about 1041 millimeters (41 inches), and mean annual temperature is about 11.1 degrees C (52 degrees F).
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Fluventic Hapludolls
TYPICAL PEDON: Dearborn loam - on a nearly level slope in a cultivated field at an elevation of about 178 meters (585 feet) above MSL. (Colors are for moist soil unless otherwise stated.)
A1--0 to 10 centimeters (0 to 4 inches); very dark grayish brown (10YR 3/2) loam, brown (10YR 5/3) dry; moderate medium granular structure; friable; many fine roots; 5 percent limestone channers; violently effervescent; slightly alkaline; clear smooth boundary.
A2--10 to 25 centimeters (4 to 10 inches); dark brown (10YR 3/3) loam, brown (10YR 5/3) dry; moderate medium subangular blocky structure; friable; common fine roots; 5 percent limestone channers; violently effervescent; slightly alkaline; clear smooth boundary. (Combined thickness of the A horizon is 25 to 41 centimeters or 10 to 16 inches)
Bw--25 to 41 centimeters (10 to 16 inches); brown (10YR 4/3) clay loam; weak coarse subangular blocky structure; firm; common fine roots; few distinct dark grayish brown (10YR 4/2) organic coatings on faces of peds and lining root channels; 8 percent limestone channers; violently effervescent; slightly alkaline; abrupt smooth boundary. (10 to 46 centimeters or 4 to 18 inches thick)
2C1--41 to 122 centimeters (16 to 48 inches); brown (10YR 4/3) extremely channery coarse sandy loam; massive; very friable; common fine roots; 70 percent limestone channers and flagstones; violently effervescent; slightly alkaline; gradual wavy boundary.
2C2--122 to 152 centimeters (48 to 60 inches); brown (10YR 4/3) extremely channery sandy clay loam; massive; firm; few fine roots; 60 percent limestone channers and flagstones; violently effervescent; slightly alkaline.
TYPE LOCATION: Dearborn County, Indiana; about 2.4 miles southeast of St. Leon; 400 feet west and 900 feet north of the southeast corner of sec. 7, T. 7 N., R. 1 W. USGS Cedar Grove, Indiana topographic quadrangle: lat. 39 degrees 16 minutes 46 seconds N. and long. 084 degrees 54 minutes 50 seconds W., NAD 27, (UTM Zone 16, 679939 easting and 4349868 northing, NAD 83).
RANGE IN CHARACTERISTICS:
Thickness of the solum: 25 to 76 centimeters (10 to 30 inches)
Thickness of the mollic epipedon: 25 to 41 centimeters (10 to 16 inches)
Rock fragments: dominantly very strongly cemented or indurated limestone channers and flagstones, and includes gravel
Reaction: slightly alkaline or moderately alkaline throughout the series control section
A or Ap horizon:
Hue: 7.5YR or 10YR
Value: 2 or 3
Chroma: 2 or 3
Texture: commonly loam, silt loam, and less commonly fine sandy loam, or channery silt loam
Rock fragment content: 3 to 25 percent channers and flagstones
Calcium carbonate equivalent: 10 to 25 percent
Bw horizon:
Hue: 7.5YR or 10YR
Value: 3 or 4
Chroma: 3 or 4
Texture: loam, clay loam, sandy loam, and their flaggy or channery analogs
Clay content: 15 to 30 percent
Sand content: 25 to 78 percent
Rock fragment content: 5 to 34 percent channers and flagstones
Calcium carbonate equivalent: 10 to 30 percent
2C horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5
Chroma: 3 or 4
Texture: very flaggy, very channery, extremely flaggy, or extremely channery analogs of coarse sandy loam, sandy loam, loam, sandy clay loam
Clay content: 10 to 26 percent
Sand content: 25 to 78 percent
Rock fragment content: 35 to 80 percent channers and flagstones in individual layers and average more than 50 percent, stones range from 0 to 10 percent
Calcium carbonate equivalent: 15 to 30 percent
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The Dearborn soils are on narrow flood plains, and alluvial fans. Slope gradient ranges from 0 to 2 percent. These soils formed in alluvium primarily derived from Ordovician-age interbedded limestone and calcareous shale. Mean annual precipitation ranges from 1016 to 1168 mm (40 to 46 inches), and mean annual temperature ranges from 10.5 to 13 degrees C (51 to 56 degrees F). Frost free period ranges from 150 to 190 days. Elevation ranges from 128 meters (420 feet) to 243 meters (800 feet).
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carmel, Eden, Pate, and Woolper soils on adjacent hills, and Huntington and Wirt soils in flood plains. The well drained, deep Carmel, the well drained, moderately deep Eden, and the well drained, deep or very deep Pate soils are on hill slopes. The well drained, very deep Woolper soils are on toeslopes and lower lying backslopes. The well drained Huntington and Wirt soils do not have significant amounts of rock fragments within 102 cm (40 inches) of the surface, and typically are on slightly higher lying flood-plain steps.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. Saturated hydraulic conductivity is high (14.11 to 42.34 micrometers/s). Permeability is moderately rapid. The potential for surface water runoff is negligible or very slow. These soils are subject to frequent or occasional, very brief periods of flooding.
USE AND VEGETATION: Most areas are used for hay and pasture, and some areas are in forest or wildlife habitat. The native vegetation is deciduous, mixed trees including oaks, American beech, elm, hickory, buckeye, sugar maple, yellow poplar, white ash, and green ash.
DISTRIBUTION AND EXTENT: Southeastern Indiana. The series is of moderate extent in MLRA 121.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Dearborn and Ohio Counties, Indiana, 1979.
REMARKS: Diagnostic horizons and features recognized in this pedon are: 1) Mollic epipedon - the zone from 0 to 25 cm (0 to 10 inches) (A1, A2 horizons), and 2) the cambic horizon from 25 to 41 cm (10 to 16 inches) (Bw horizon).
The representative component and horizon data is in DMU# 357,882 (horizon data includes both loam and silt loam range, with current Rv of silt loam that will be revised to loam). The representative component and horizon data for the channery phase is in DMU# 357,883.
Laboratory data for the typical pedon- S77IN129 is from the Agricultural Experiment Station, Purdue University.