LOCATION AUREOLA                 IA

Established Series
Rev. KDV-DBO-AWY
10/2012

AUREOLA SERIES

The Aureola series consists of very deep, well drained soils formed on uplands in 50 to 100 centimeters (19.7 to 39.4 inches) of loamy sediments that overlie sandy material weathered from calcareous sandstone. Slope ranges from 0 to 16 percent. Mean annual air temperature is about 8 degrees C. Mean annual precipitation is about 840 millimeters (33.1 inches).

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Typic Hapludolls

TYPICAL PEDON: Aureola loam on a convex northeast-facing slope of 3 percent - cultivated. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 23 centimeters (0 to 9.1 inches); very dark brown (10YR 2/2) loam, dark grayish brown (10YR 4/2) dry; weak very fine granular structure; friable; neutral; abrupt smooth boundary.

A--23 to 36 centimeters (9.1 to 14.2 inches); very dark brown (10YR 2/2) and very dark grayish brown (10YR 3/2) loam, brown (10YR 4/3) dry; weak very fine granular structure; friable; neutral; gradual smooth boundary.

BA--36 to 48 centimeters (14.2 to 18.9 inches); dark brown (10YR 3/3) loam, brown (10YR 4/3) dry; weak very fine subangular blocky structure; friable; very dark grayish brown (10YR 3/2) coats on faces of peds; neutral; gradual smooth boundary.

Bw1--48 to 66 centimeters (18.9 to 26 inches); yellowish brown (10YR 5/4) loam; weak very fine and fine subangular blocky structure; friable; dark yellowish brown (10YR 4/4) coats on faces of peds; neutral; gradual smooth boundary.

Bw2--66 to 84 centimeters (26 to 33.1 inches); yellowish brown (10YR 5/6) sandy loam; weak fine and medium subangular blocky structure; very friable; neutral; abrupt smooth boundary. (Combined thickness of the Bw horizons is 10 to 25 inches.)

2C1--84 to 122 centimeters (33.1 to 48 inches); brownish yellow (10YR 6/6) loamy fine sand; few fibrous roots; strongly alkaline; violently effervescent; clear wavy boundary.

2C2--122 to 152 centimeters (48 to 59.8 inches); light olive brown (2.5Y 5/6) loamy fine sand; few fibrous roots; strongly alkaline; violently effervescent.

TYPE LOCATION: Major Land Resource Area (MLRA) 104-Eastern Iowa and Minnesota Till Prairies, Floyd County, Iowa subset; about 3 miles east of Marble Rock; 2,415 feet north and 190 feet east of the southwest corner, sec. 12, T. 94 N., R. 17 W.; USGS Greene topographic quadrangle; lat. 42 degrees 58 minutes 16 seconds N. and long. 92 degrees 48 minutes 30 seconds W.; NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--25 to 49 centimeters (9.8 to 19.3 inches)
Depth to carbonates--50 to 100 centimeters (19.7 to 39.4 inches)
Depth to sandy material weathered from calcareous sandstone--50 to 100 centimeters (19.7 to 39.4 inches)
Clay content of the particle-size control section (weighted average)--10 to 15 percent
Sand content of the particle-size control section (weighted average)--40 to 60 percent
Rock fragment content--less than 5 percent

A or Ap horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--loam, sandy loam, or silt loam
Clay content--10 to 20 percent
Sand content--30 to 60 percent
Reaction--slightly acid or neutral
Thickness--25 to 46 centimeters (9.8 to 18.1 inches)

AB horizon:
Hue--10YR
Value--3
Chroma--2 or 3
Texture--loam or sandy loam
Clay content--10 to 15 percent
Sand content--40 to 60 percent
Reaction--slightly acid or neutral
Thickness--0 to 18 centimeters (0 to 7.1 inches)

BA horizon:
Hue--10YR
Value--3
Chroma--3
Texture--loam or sandy loam
Clay content--10 to 15 percent
Sand content--40 to 60 percent
Reaction--slightly acid or neutral
Thickness--0 to 18 centimeters (0 to 7.1 inches)

Bw horizon:
Hue--10YR
Value--4 to 6
Chroma--3 to 6
Texture--loam or sandy loam
Clay content--10 to 15 percent
Sand content--40 to 65 percent
Reaction--slightly acid or neutral
Thickness--25 to 65 centimeters (9.8 to 25.6 inches)

2C horizon:
Hue--10YR or 2.5Y
Value--5 to 7
Chroma--3 to 6
Texture--loam fine sand or sand
Clay content--less than 10 percent
Sand content--80 to 95 percent
Reaction--slightly alkaline to strongly alkaline

COMPETING SERIES:
These are the Augusta Lake, Bertram, Bolan, Dickinson, Elrick, Etter, Filley, Gardencity, Olin, Ridgeport, Roine, Wadenill, and Zenor soils.
Augusta Lake--contain carbonates at depths between 100 and 150 centimeters (39.4 and 59.1 inches)
Bertram--have a lithic contact with limestone bedrock at depths between 50 and 100 centimeters (19.7 and 39.4 inches)
Bolan--contain carbonates at a depth greater than 120 centimeters (47.2 inches)
Dickinson--contain carbonates at a depth greater than 150 centimeters (59.1 inches)
Elrick--contain carbonates at depths greater than 100 centimeters (39.4 inches)
Etter--differentia between Etter and Aureola are unclear; combining these series should be considered
Filley--do not contain carbonates in the series control section
Gardencity--have a frequently saturated zone within depths of 0.75 to 1.8 meters (29.5 to 70.9 inches)
Olin--contain carbonates at depths greater than 125 centimeters (49.2 inches)
Ridgeport--contain 5 to 15 percent coarse fragments in the lower third of the series control section
Roine--contains 10 to 30 percent clay in the lower third of the series control section
Wadenill--contain less than 80 percent sand in the lower third of the series control section
Zenor--average more than 5 percent coarse fragments in the lower third of the series control section

GEOGRAPHIC SETTING:
Parent material--50 to 100 centimeters (19.7 to 39.4 inches) of loamy surficial sediment and sandy material weathered from calcareous sandstone. In some areas red Cretaceous clay is at a depth of 100 to 150 centimeters (39.4 to 59.1 inches) or more.
Landform--nearly level to gently sloping ridge crests and gently sloping to strongly sloping side slopes
Slope--0 to 16 percent
Elevation--300 to 400 meters (984 to 1,313 feet) above sea level
Mean annual air temperature--7 to 10 degrees C.
Mean annual precipitation--735 to 940 millimeters (28.9 to 37 inches)
Frost-free period--160 to 195 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Near the type location, these are the Floyd, Ostrander, Rockton, and Waukee soils.
Floyd--occur on concave foot slopes adjacent to upland drainageways and have a frequently saturated zone between depths of 0.3 and 1 meter (11.8 and 39.4 inches)
Ostrander--typically occur higher on the landscape and average 20 to 27 percent clay in the particle-size control section
Rockton--occur on summits and shoulder slopes on uplands, high structural benches, and strath terraces and have limestone bedrock at a depth between 50 and 100 centimeters (19.7 and 39.4 inches)
Waukee--occur on treads and risers on stream terraces and have carbonates at a depth greater than 180 centimeters (70.9 inches)

DRAINAGE AND PERMEABILITY:
Drainage class--well drained--a frequently saturated zone does not occur within a depth of 1.8 meters (70.9 inches) during most years
Saturated hydraulic conductivity--moderately high (1.0 to 10.0 micrometers per second) in the loamy surficial sediment and high (10.0 to 100.0 micrometers) in the underlying sandy material

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, legume hay, small grains, and soybeans. The native vegetation is big bluestem, indiangrass, switchgrass, and other grasses of the tall grass prairie.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRAs--Eastern Iowa and Minnesota Till Prairies (104)
Local physiographic area--Iowa Erosion Surface
LRR M; northeastern Iowa and possibly southeastern Minnesota
Extent--small

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana

SERIES ESTABLISHED:
Floyd County, Iowa, 1989. The name is taken from a small, unincorporated village in Floyd County.

REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters 9.8 to 39.4 inches)
Series control section--the zone from the surface to a depth of 150 centimeters (59.1 inches)

Diagnostic horizons and features recognized in this pedon include:
Mollic epipedon--the zone from the surface to a depth of 48 centimeters (18.9 inches) (Ap, A, and BA horizons)
Cambic horizon--the zone from 36 to 84 centimeters (14.2 to 33.1 inches) (BA, Bw1, and Bw2 horizons); udic moisture regime.

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National Cooperative Soil Survey
U.S.A.