LOCATION GERYUNE ILEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Oxyaquic Argiudolls
TYPICAL PEDON: Geryune silt loam - on a southwest-facing convex slope of 3 percent in a cropped field at an elevation of 262 meters (858 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 23 cm (0 to 9 inches); very dark gray (10YR 3/1) silt loam, gray (10YR 5/1) dry; moderate very fine subangular blocky structure parting to weak very fine and fine granular; friable; many very fine roots; moderately acid; abrupt smooth boundary. [15 to 30 cm (6 to 12 inches) thick]
AB--23 to 36 cm (9 to 14 inches); dark brown (10YR 3/3) silt loam, brown (10YR 5/3) dry; weak medium platy structure parting to moderate fine granular; friable; many very fine Roots; few distinct discontinuous very dark grayish brown (10YR 3/2) organic coatings and white (10YR 8/1) dry, silt coatings on faces of peds; neutral; clear smooth boundary. [0 to 15 cm (0 to 6 inches) thick]
Bt1--36 to 48 cm (14 to 19 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate very fine subangular blocky structure; friable; many very fine roots; common distinct brown (10YR 4/3) clay films on faces of peds; few distinct white (10YR 8/1) dry, silt coatings on faces of peds; few very dark gray (10YR 3/1) worm channel fillings; neutral; gradual smooth boundary.
Bt2--48 to 71 cm (19 to 28 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate fine subangular blocky structure; friable; common very fine roots; common distinct brown (10YR 4/3) clay films on faces of peds; few distinct white (10YR 8/1) dry, silt coatings on faces of peds; few very dark gray (10YR 3/1) worm channel fillings; neutral; abrupt smooth boundary. [Combined thickness of the Bt horizon is 25 to 71 cm (10 to 28 inches).]
2Bt3--71 to 94 cm (28 to 37 inches); brown (7.5YR 4/4) clay loam; moderate medium prismatic structure parting to moderate medium and coarse angular blocky; friable; few very fine roots; common distinct brown (10YR 4/3) clay films and many distinct pale brown (10YR 6/3) dry, silt coatings on vertical faces of peds; common medium distinct brown (7.5YR 5/2) iron depletions in the matrix; 10 percent gravel; neutral; clear smooth boundary.
2Bt4--94 to 109 cm (37 to 43 inches); brown (7.5YR 4/4) clay loam; moderate medium prismatic structure; friable; few very fine roots; common distinct brown (7.5YR 4/2) clay films on vertical faces of peds; 10 percent gravel; neutral; clear wavy boundary. [Combined thickness of the 2Bt horizon is 10 to 64 cm (4 to 25 inches thick).]
2C--109 to 183 cm (43 to 72 inches); brown (7.5YR 5/4) loam; massive; friable; few distinct brown (7.5YR 4/2) clay films in worm channels in upper 6 inches; 12 percent gravel; strongly effervescent; moderately alkaline.
TYPE LOCATION: Boone County, Illinois; about 8 km (5 miles) north of Garden Prairie; 76 m (250 feet) north and 79 m (260 feet) east of the southwest corner of sec. 36, T. 45 N., R. 4 E.; USGS Garden Prairie topographic quadrangle; lat. 42 degrees 19 minutes 43 seconds N. and long. 88 degrees 43 minutes 26 seconds W., NAD 27; UTM Zone 16, 357958 easting and 4687704 northing, NAD 83.
RANGE IN CHARACTERISTICS: The depth to the base of the argillic horizon ranges from 76 to 127 cm (30 to 50 inches). The depth to horizons with more than 15 percent sand ranges from 56 to 102 cm (22 to 40 inches). The depth to carbonates is 76 to 127 cm (30 to 50 inches). Rock fragment content ranges from 2 to 15 percent in the lower two parts of the series control section. The mollic epipedon is 25 to 51 cm (10 to 20 inches thick).
The Ap, A, or AB horizon has hue of 10YR, value of 2 or 3 (4 or 5 dry), and chroma of 1 to 3. Texture is silt loam. Reaction ranges from moderately acid to neutral.
The Bt or BA horizon has hue of 10YR, value of 4 to 6, and chroma of 3 or 4. It averages 27 to 34 percent clay, some subhorizons range from 24 to 35 percent. Texture is silty clay loam or silt loam. Reaction ranges from strongly acid to neutral.
The 2Bt, 2BC, or 2Bk horizon has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 3 to 6. Redoximorphic features have chroma of 2 to 8. Texture is clay loam, loam, or sandy clay loam. Clay content ranges from 20 to 34 percent and sand content from 25 to 60 percent. Reaction ranges from moderately acid to slightly alkaline. Calcium carbonate equivalent is 0 to 20 percent.
The 2C horizon has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 3 to 6. Redoximorphic features have chroma of 2 to 8. Texture is loam or sandy loam. The 2C horizon averages 15 to 20 percent clay and ranges from 35 to 55 percent sand. Reaction is slightly alkaline or moderately alkaline. Many pedons have secondary carbonates accumulations in the upper part. The calcium carbonate equivalent is 15 to 40 percent.
COMPETING SERIES: These are the Assumption, Aviston, Barrington, Blackberry, Buckhart, Catlin, Clare, Dana, Danabrook, Graymont, Harrison, Keltner, Saybrook, and Totanang series. Assumption, Graymont, and Saybrook soils average more than 20 percent clay in the lower part of the series control section. Aviston, Blackberry, Buckhart, Catlin, and Harrison soils do not have horizons with more than 15 percent sand within a depth of 102 cm (40 inches). Barrington and Clare soils have a poorly graded sand fraction in the lower one-half of the series control section. Dana and Danabrook soils have a bulk density of more than 1.70 g/cm3 in the lower part of the series control section. Keltner soils have a paralithic contact within a depth of 152 cm (60 inches). Totanang soils have more than 15 percent rock fragments in the lower part of the series control section.
GEOGRAPHIC SETTING: Geryune soils are on till plains and moraines. Slope ranges from 0 to 5 percent. Geryune soils formed in 56 to 102 cm (22 to 40 inches) of loess or other silty material and in the underlying loamy till. Mean annual air temperature ranges from 7 to 11 degrees C (45 to 52 degrees F), mean annual precipitation from 760 to 1020 mm (30 to 40 inches), frost free days range from 140 to 180 days, and the elevation ranges from 207 to 311 meters (679 to 1020 feet) above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Elburn, Lismod, Parmod, and Pella soils. The somewhat poorly drained Elburn and Lismod soils are on lower positions on the landform. The well drained Parmod soils are on similar landform positions nearby where the loess or silty mantle is thinner. The poorly drained Pella soils are in drainageways and slight depressions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained. An intermittent apparent high water table is at a depth of 61 to 107 cm (2.0 to 3.5 feet) below the surface at some time between February and April in most years. The potential for surface runoff is low. Saturated hydraulic conductivity is moderately high or high (4.23 to 14.11 micrometers per second). Permeability is moderate.
USE AND VEGETATION: Most areas are cropped. Principal crops are corn, soybeans, small grain, and hay. Native vegetation is prairie grasses (tall prairie).
DISTRIBUTION AND EXTENT: Northern Illinois. The extent is small in MLRA 95B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Boone County, Illinois, 1996. The name Geryune is from Geryune Creek which is near the type location.
REMARKS: This soil was formerly mapped Saybrook in Boone County and Dana and Sidell in McHenry County. Through MLRA update activities these areas were determined to have a clay content in the lower part of the series control section averaging 15 to 20 percent. Also Geryune soils have a bulk density of less than 1.70 g/cm3 in the lower part of the series control section.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface to 36 cm (14 inches) (Ap and AB horizons); argillic horizon - the zone from 36 to 109 cm (14 to 43 inches) (Bt1, Bt2, 2Bt3, and 2Bt4 horizons); discontinuity at a depth of 71 cm (28 inches) - the contact between the Bt2 and 2Bt3 horizons; udic moisture regime.