LOCATION COAL PALACE IA

Established Series
Rev. WAV-JCD-RPD
09/2025

COAL PALACE SERIES

The Coal Palace series consists of very deep, well drained, very slowly to slowly permeable soils that formed in reclaimed mine spoils. Slopes range from 1 to 18 percent. Mean annual precipitation is about 930 millimeters, and mean annual air temperature is about 10 degrees C (50 degrees F).

TAXONOMIC CLASS: Clayey, spolic, mixed, active, acid, mesic, shallow Anthrodensic Udorthents

TYPICAL PEDON: Coal Palace silty clay, on a 1 percent slope in grass/herbaceous cover in a wildlife area, at an elevation of 219 meters (718 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)

^AC--0 to 12 centimeters; brown (10YR 4/3) silty clay; weak fine subangular blocky and granular structure; friable; common very fine to medium roots; common fine prominent strong brown (7.5YR 4/6) masses of oxidized iron; 2 percent fine to coarse gravel; slightly alkaline; clear wavy boundary. (3 to 20 centimeters thick)

^C--12 to 40 centimeters; 95 percent olive brown (2.5Y 4/3) and 5 percent black (10YR 2/1) silty clay; massive; friable; few fine prominent strong brown (7.5YR 4/6) and yellowish red (5YR 4/6) masses of oxidized iron; few fine distinct gray (10YR 5/1) iron depletions; 1 percent fine to coarse gravel and 5 percent fine to coarse paragravel; very strongly acid; clear smooth boundary. (12 to 50 centimeters thick)

^Cd1--40 to 112 centimeters; dark grayish brown (2.5Y 4/2) silty clay loam; massive; firm; 2 percent prominent brownish yellow (10YR 6/8) masses of oxidized iron; 1 percent fine to coarse gravel and paragravel; ultra acid; clear smooth boundary.

^Cd2--112 to 130 centimeters; dark grayish brown (2.5Y 4/2) silty clay loam; massive; firm; 4 percent fine to coarse gravel and paragravel; ultra acid; clear smooth boundary.

^Cd3--130 to 155 centimeters; dark gray (10YR 4/1) clay; massive; firm; 1 percent fine to coarse gravel and 4 percent fine to coarse paragravel; ultra acid; clear smooth boundary.

^Cd4--155 to 180 centimeters; dark grayish brown (2.5Y 4/2) clay; massive; firm; 5 percent fine to coarse gravel and paragravel; ultra acid; clear smooth boundary.

^Cd5--180 to 200 centimeters; dark gray (10YR 4/1) silty clay loam; massive; firm; 5 percent fine to coarse gravel and paragravel; ultra acid.

TYPE LOCATION: Mahaska County, Iowa; about 3 miles west of the town of Beacon; 120 feet west and 680 feet north of SE corner of sec. 19, T. 75 N., R. 16 W.; USGS Oskaloosa topographic quadrangle; lat. 41.2797720 degrees and long. -92.7374720 degrees, WGS84.

RANGE IN CHARACTERISTICS:
Soil fragments and isolated peds of relict genetic horizons of pre-mined soils may be present in up to 10 percent of the volume; randomly distributed throughout and are disordered relative to any plane in the profile.
Soil fragments: with identifiable properties such as redoximorphic features, higher chroma, clay films, or coatings that are characteristic of their previous formation. Particle-size control section: averages 35 to 50 percent clay.

^AC or ^A horizon
Hue: 7.5YR, 10YR, or 2.5Y
Value: 2 to 5
Chroma: 1 to 3
Texture: silt loam, silty clay, or silty clay loam, or the paragravelly analogs of these textures
Clay content: 20 to 42 percent
Sand content: 5 to 20 percent
Rock fragment content: 1 to 14 percent coal or sandstone gravel; content of coal is less than 5 percent
Pararock fragment content: 1 to 20 percent shale, clayey paragravel
Reaction: extremely acid to slightly alkaline

^C horizon
Hue: 7.5YR, 10YR, or 2.5Y
Value: 3 to 5
Chroma: 1 to 4
Texture: clay loam, silty clay loam, silty clay, or clay, or the paragravelly analogs of these textures
Clay content: 28 to 50 percent
Sand content: 5 to 30 percent
Rock fragment content: 1 to 14 percent coal or sandstone gravel; content of coal is less than 5 percent
Pararock fragment content: 5 to 34 percent shale, clayey paragravel
Reaction: ultra acid to strongly acid

^Cd horizon
Hue: 10YR or 2.5Y
Value: 2 to 5
Chroma: 1 to 4
Texture: clay loam, silty clay loam, silty clay, or clay, or the paragravelly, very paragravelly, or extremely paragravelly analogs of these textures
Clay content: 28 to 55 percent
Sand content: 5 to 40 percent
Rock fragment content: 5 to 14 percent coal or sandstone gravel; content of coal is less than 5 percent
Pararock fragment content: 5 to 90 percent shale, clayey paragravel
Reaction: ultra acid to very strongly acid

COMPETING SERIES: There are no other series in this family. The Foyil, Hollybrook and Talala soil are in the same subgroup but are nonacid.

GEOGRAPHIC SETTING: Coal Palace soils are on slopes of hills and valleys constructed after strip mining operations. Reclamation operations resulted in landforms similar to pre-mining contours. Slopes range from 1 to 18 percent. The soils were excavated and replaced with loamy and clayey material weathered from shale of Pennsylvanian age. Mean annual precipitation ranges from 875 to 1000 mm (34 to 39 inches). Mean annual temperature ranges from 9 to 11 degrees C (48 to 52 degrees F). Frost-free period is 145 to 230 days. Elevation is 100 to 305 meters above mean sea level.

GEOGRAPHICALLY ASSOCIATED SOILS: These include Keswick, Lindley, Munterville, and Nodaway soils. These soils have not been disturbed by mining activities.
Keswick--are on higher landscape positions on side slopes.
Lindley--are on higher landscape positions on side slopes.
Munterville--are on convex side slopes and escarpment-like areas that parallel major streams.
Nodaway--are on lower landscape positions on flood plains.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. Potential for surface runoff is high to very high. Saturated hydraulic conductivity is moderately low to moderately high (0.1 - 10 micrometers per second) in the upper part of the series control section. Saturated hydraulic conductivity is very low to moderately low (0.01 - 1.0 micrometers per second) in the lower part.

USE AND VEGETATION: Used mainly for pasture and light grazing, wildlife habitat, and recreation. Vegetation mainly consists of cool season pasture mixes that include alfalfa, clover, redtop, brome, timothy, and a variety of other cool season species. Warm season vegetation consists of a variety of grasses such as Big Bluestem, Indian grass, Canada Wild Rye, and forbs such as coneflowers, asters, and goldenrod among others.

DISTRIBUTION AND EXTENT: Illinois and Iowa Deep Loess and Drift (MLRA 108) and Iowa and Missouri Heavy Till Plain (MLRA 109). The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Salina, Kansas

SERIES ESTABLISHED: Mahaska County, Iowa, 2025.

REMARKS:
These soils are the result of pre-1994 strip mining. The landscape was returned to its original elevation and contour, and topsoil was created by incorporating organic matter into the reshaped mine spoil. The subsurface is formed in replaced soil and pararock fragments from loess, till, shale and sandstone of Pennsylvanian age. The substratum is a mixture of shale and sandstone overburden moved during mining. Any redox features present in the profile are not indicators of modern drainage conditions.

Diagnostic horizons and features in this pedon are:
Particle-size control section: the zone from 25 to 40 cm.
Series control section: the zone from 0 to a depth of 65 cm.
Ochric epipedon: 0 to 12 cm.
Densic contact: at a depth of 40 cm.

The name is from the Coal Palace Exhibition center that stood in Ottumwa, Iowa from 1890 until 1892.

Taxonomy version: Keys to Soil Taxonomy, thirteenth edition, 2022.

ADDITIONAL DATA: User Pedon ID for the type location is 2024IA123303.

National Cooperative Soil Survey
U.S.A.