LOCATION WELLROCK INEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Ultic Hapludalfs
TYPICAL PEDON: Wellrock silt loam on 12 percent slope in a forested area at an elevation of about 280 meters (920 feet) above MSL. (Colors are for a moist soil unless stated otherwise.)
Oi--0 to 3 cm (0 to 1 inches); roots and partially decomposed leaves from mixed deciduous trees. [0 to 5 cm (0 to 2 inches) thick]
A--3 to 10 cm (1 to 4 inches); very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; moderate medium granular structure; friable; many fine and medium roots; very strongly acid; clear smooth boundary. [3 to 13 cm (1 to 5 inches) thick]
EB--10 to 20 cm (4 to 8 inches); yellowish brown (10YR 5/4) silt loam; moderate medium granular structure; friable; many fine and medium roots; extremely acid; clear wavy boundary. [13 to 38 cm (5 to 15 inches) thick]
Bt1--20 to 51 cm (8 to 20 inches); yellowish brown (10YR 5/6) silty clay loam; weak medium subangular blocky structure; firm; common fine and medium roots; common distinct brown (7.5YR 4/4) clay films on faces of peds; very strongly acid; clear smooth boundary.
Bt2--51 to 71 cm (20 to 28 inches); yellowish brown (10YR 5/6) silty clay loam; moderate medium subangular blocky structure; firm; common fine and medium roots; many distinct brown (7.5YR 4/4) clay films on faces of peds; very strongly acid; clear smooth boundary. [Combined thickness of the Bt horizon is 41 to 71 cm (16 to 28 inches).]
2Bt3--71 to 91 cm (28 to 36 inches); yellowish brown (10YR 5/6) silty clay loam; moderate coarse prismatic structure parting to moderate medium angular blocky; firm; few fine roots; many distinct brown (7.5YR 4/4) clay films on faces of peds; common pale brown (10YR 6/3) silt coats on faces of peds; 3 percent parachanners; extremely acid; clear wavy boundary.
2Bt4--91 to 132 cm (36 to 52 inches); yellowish brown (10YR 5/4) extremely parachannery silt loam; common medium distinct light brownish gray (2.5Y 6/2) mottles; weak fine subangular blocky structure; friable; common distinct dark yellowish brown (10YR 4/4) clay films on faces of peds; 60 percent parachanners; very strongly acid; clear smooth boundary. [Combined thickness of the 2Bt horizon is 46 to 66 cm (18 to 26 inches).]
2Cr--132 to 152 cm (52 to 60 inches); yellowish brown (10YR 5/4) fractured, moderately cemented siltstone interbedded with thin layers of weakly cemented shale and very strongly cemented siltstone.
TYPE LOCATION: Brown County, Indiana; about 3.5 miles south of Nashville; 875 feet east and 75 feet north of the center of sec. 6, T. 8 N., R. 3 E; USGS Nashville, Indiana topographic quadrangle; lat. 39 degrees 9 minutes 31.2 seconds N. and long. 86 degrees 14 minutes 5 seconds W., UTM Zone 16, 566118 easting and 4334663 northing, NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of the loess: 56 to 97 cm or 22 to 38 inches
Depth to the base of the argillic horizon: 97 to 147 cm or 38 to 58 inches
Depth to bedrock (paralithic contact): 102 to 152 cm or 40 to 60 inches
Particle-size control section: averages 24 to 32 percent clay, and 1 to 5 percent sand
Pararock fragments: dominantly weakly or moderately cemented siltstone
A horizon (2 to 13 cm or 1 to 5 inches thick):
Hue: 10YR
Value: 3 or 4
Chroma: 2 or 3
Texture: silt loam
Reaction: very strongly acid or strongly acid
Ap, where present:
Hue: 10YR
Value: 4 or 5
Chroma: 3 or 4
Texture: silt loam
Reaction: very strongly acid to neutral
EB, BE, or E/A horizon:
Hue: 10YR
Value: 5 or 6
Chroma: 4 to 6
Clay content: 14 to 26 percent
Sand content: 2 to 5 percent sand
Texture: silt loam
Reaction: extremely acid or very strongly acid, and ranges to slightly acid in limed areas
Bt horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 4 to 8
Texture: silt loam or silty clay loam
Clay content: 24 to 34 percent
Sand content: 2 to 5 percent
Reaction: extremely acid or very strongly acid
2Bt or 2BC horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 4 to 6
Texture: silt loam or silty clay loam, or their channery to extremely channery analogues
Clay content: 15 to 32 percent
Sand content: 5 to 15 percent
Pararock fragment content: 10 to 65 percent
Reaction: extremely acid or very strongly acid
2Cr horizon:
Hue: 10YR or 2.5Y
Value: 4 to 6
Chroma: 3 to 6
COMPETING SERIES: These are the Bearthicket, Cidermill, Elk, Elkinsville, Olephant, Parke, Pike, Rickert, Tobinsport, and Wellston soils. Bearthicket, Cidermill, Elk, Elkinsville, Olephant, Parke, Pike, Rickert and Tobinsport soils do not have a paralithic contact in the series control section. Wellston soils typically have a lithic contact and average more than 15 percent sand in the lower part of the series control section.
GEOGRAPHIC SETTING: Wellrock soils are on moderately sloping and strongly sloping shoulders and backslopes of hills. Slopes range from 6 to 18 percent. They formed in 56 to 97 cm (22 to 38 inches) of loess and the underlying residuum from siltstone. The bedrock is from the lower part of the Spickert Knob Formation, Borden Group, in Indiana (See Remarks). The mean annual temperature ranges from 11 to 14 degrees C (52 to 57 degrees F) and the mean annual precipitation ranges from 1016 to 1168 mm (40 to 46 inches). Frost free days range from 170 to 200. Elevation ranges from 105.2 to 305 meters (345 to 1000 feet) above mean sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brownstown, Gilwood, Gnawbone, Spickert and Wrays soils. The moderately deep, well drained Brownstown soils are on backslopes. The moderately deep, well drained Gilwood and Gnawbone soils are typically on shoulders and the upper part of backslopes. The moderately well drained Spickert soils have a fragipan and are typically on summits and shoulders. The well drained Wrays soils have a lithic contact and are on similar landform positions as the Wellrock soils.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. Saturated hydraulic conductivity is moderately high (1.41 to 4.23 micrometers/s). Permeability is moderately slow. The potential for surface water runoff is medium or high.
USE AND VEGETATION: Most areas are in mixed hardwood forest, the native vegetation. Some areas are used for pasture and a few areas are used for growing row crops.
DISTRIBUTION AND EXTENT: This series is of small extent in MLRA 120C. Wellrock soils are in southeastern and south central Indiana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Scott County, Indiana, 1995. The name is coined.
REMARKS: Wellrock soils were previously correlated as the Wellston series. Geological Survey Occasional Paper 43 from the Indiana Department of Natural Resources describes the Spickert Knob Formation in Indiana.
Diagnostic horizons recognized in this pedon are:
1) Ochric epipedon: 0 to 20 cm or 8 inches (A and EB horizons)
2) Argillic horizon: 20 to 132 cm or 8 to 52 inches (Bt1, Bt2, 2Bt3, 2Bt4 horizons)
3) Paralithic contact: at 132 to 152 cm or 52 to 60 inches
ADDITIONAL DATA: Lab data for this pedon is published in Station Bulletin No. 494, Agricultural Experiment Station, Purdue University; file no. BR8104.