LOCATION CROKE MNEstablished Series
TAXONOMIC CLASS: Coarse-silty over clayey, mixed over smectitic, superactive, frigid Oxyaquic Hapludolls
TYPICAL PEDON: Croke loam with a plane level slope on a glacial lake plain in a cultivated field. (Colors are for moist soil unless otherwise stated)
Ap--0 to 9 inches; black (10YR 2/1) loam, dark gray (10YR 4/1) dry; weak fine subangular blocky structure; very friable; neutral; abrupt smooth boundary. (7 to 12 inches thick)
Bw--9 to 19 inches; dark grayish brown (2.5Y 4/2) very fine sandy loam; weak medium subangular blocky structure; very friable; common fine prominent black (10YR 2/1) oxide accumulations; neutral; clear smooth boundary. (4 to 12 inches thick)
C--19 to 25 inches; light olive brown (2.5Y 5/4) very fine sandy loam; weak medium subangular blocky structure; very friable; common fine prominent black (10YR 2/1) oxide accumulations; neutral; abrupt smooth boundary. (0 to 20 inches thick)
2Cg1--25 to 38 inches; olive gray (5Y 5/2) silty clay; few fine prominent yellowish brown (10YR 5/6) redoximorphic concentrations; moderate medium subangular blocky structure; firm; strong effervescence; moderately alkaline; gradual smooth boundary.
2Cg2--38 to 60 inches; gray (5Y 5/1) silty clay; common fine and medium prominent yellowish brown (10YR 5/6) redoximorphic concentrations; moderate medium subangular blocky structure parting to moderate very fine angular blocky; firm; strong effervescence; moderately alkaline.
TYPE LOCATION: Traverse County, Minnesota; about 6 miles east of Dumont; about 200 feet south and 250 feet east of northwest corner of sec. 22, T. 126 N., R. 45 W.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 7 to 16 inches in thickness. Thickness of solum ranges from 12 to 24 inches and depth to carbonates ranges from 12 to 30 inches. Depth to the 2C horizon ranges from 20 to 40 inches. The upper sediments average less than 18 percent clay and less than 15 percent fine sand and coarser. The 2C horizon typically averages between 40 to 55 percent clay with extreme range of 35 to 60 percent.
The A horizon has value of 2 or 3, and chroma of 1. It is very fine sandy loam, loamy very fine sand, loam or silt loam. It is neutral or slightly alkaline.
The B horizon has hue of 10YR, 2.5Y or 5Y, value of 3 to 5, and chroma of 2 to 4. It is loamy very fine sand, very fine sandy loam, very fine sand, loam or silt loam. It is neutral or slightly alkaline.
The C horizon has hue of 10YR, 2.5Y or 5Y, value of 4 to 6, and chroma of 2 to 4. Some pedons have redoximorphic features. It is loamy very fine sand, very fine sandy loam, very fine sand, loam or silt loam. It is neutral through moderately alkaline.
The 2C horizon has hue of 2.5Y or 5Y, value of 4 to 6, and chroma of 1 or 2. It has few to many distinct or prominent redoximorphic features. It is typically silty clay or clay, but silty clay loam or clay loam is in the range. It is slightly or moderately alkaline.
COMPETING SERIES: No other series are in the family.
GEOGRAPHIC SETTING: Croke soils have plane or slightly convex slopes of 0 to 2 percent on glacial lake plains. They formed in a 20 to 40 inch mantle of silty or loamy glaciolacustrine sediments which overlie calcareous clayey glaciolacustrine sediments. These sediments are Late Wisconsinan in age. Mean annual air temperature is 37 to 45 degrees F, and mean annual precipitation is 18 to 23 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Augsburg, Glyndon and Wheatville soils. Augsburg soils are poorly or very poorly drained and are on slightly lower positions. Glyndon and Wheatville soils have a calcic horizon and are on similar positions. In addition, Glyndon soils have more than 40 inches of silty sediments.
DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is moderately rapid in the upper mantle and slow in the underlying sediments. Runoff is slow. A seasonal high water table is at depths of 2.5 to 5 feet at some time during the period of April through June.
USE AND VEGETATION: Nearly all of these soils are cultivated. Small grain, soybeans, sunflowers, and corn are the most common crops. Native vegetation was tall grass prairie.
DISTRIBUTION AND EXTENT: Mainly in the Red River Valley of northwestern Minnesota. It is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Traverse County, Minnesota, 1986.
REMARKS: Diagnostic horizons and features are: mollic epipedon from 0 to 9 inches; cambic horizon from 9 to 19 inches.
The classification was changed to the Oxyaquic subgroup even though the morphology of this pedon may meet the Aquic subgroup criteria because it was felt Oxyaquic better fit the water state of the series. A different pedon may need to be selected to represent the series. 01/2000.
ADDITIONAL DATA: Refer to MAES Central File Code No. 3450 for results of some laboratory analysis of a similar pedon.