LOCATION ROCKDAM WIEstablished Series
TAXONOMIC CLASS: Sandy, siliceous, frigid Entic Haplorthods
TYPICAL PEDON: Rockdam sand - on a plane, south facing, 1 percent slope in woodland at an elevation of about 990 feet. (Colors are for moist soil unless otherwise noted).
Oe--0 to 1 inch; very dark grayish brown (10YR 3/2) mucky peat (hemic material which is a mat of partially decomposed forest litter); weak thin platy structure; non-sticky; very strongly acid; abrupt wavy boundary. (0 to 2 inches thick)
A--1 to 3 inches; very dark gray (10YR 3/1) sand, gray (10YR 5/1) dry; weak fine granular structure; very friable; many fine, medium and coarse roots; very strongly acid; abrupt wavy boundary. (1 to 6 inches thick).
E--3 to 6 inches; dark grayish brown (10YR 4/2) sand, grayish brown (10YR 5/2) dry; weak medium subangular blocky structure; very friable; many fine and medium roots; very strongly acid; abrupt wavy boundary. (0 to 8 inches thick)
Bs1--6 to 10 inches; dark yellowish brown (7.5YR 3/4) sand; weak medium and coarse subangular blocky structure; very friable; common very fine and fine roots; very strongly acid; clear wavy boundary. (6 to 20 inches thick)
Bs2--10 to 19 inches; dark brown (7.5YR 4/4) sand; weak medium subangular blocky structure; very friable; common very fine and fine roots; strongly acid; clear wavy boundary. (Combined thickness of the Bs horizons ranges from 4 to 20 inches).
Bw--19 to 27 inches; yellowish brown (10YR 5/4) sand; weak coarse subangular blocky structure; very friable; few fine roots; strongly acid; clear wavy boundary. (0 to 25 inches thick)
C1--27 to 43 inches; brownish yellow (10YR 6/6) sand; single grain; loose; moderately acid; clear wavy boundary.
C2--43 to 53 inches; yellow (10YR 7/6) sand; common fine prominent reddish yellow (7.5YR 6/8) masses of iron accumulation; single grain; loose; slightly acid; clear smooth boundary.
C3--53 to 61 inches; light gray (10YR 7/2) sand; single grain; loose; common coarse distinct very pale brown (10YR 7/4) masses of iron accumulation; slightly acid.
TYPE LOCATION: Jackson County, Wisconsin; about 12.5 miles south and 2 miles west of Citypoint; 2400 feet north and 1640 feet east of the southwest corner of sec. 34, T.20N., R.1E.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 20 to 40 inches. Volume of sandstone gravel or channers ranges from 0 to 5 percent throughout. Reaction typically ranges from extremely acid to slightly acid in the solum but ranges to neutral in the upper part, where the soil is limed. Reaction ranges from very strongly acid to slightly acid in the substratum. Redox features are within 72 inches and are within 40 inches in some pedons. Saturation for 1 month or more per year in 6 out of 10 years occurs below 40 inches. Some pedons are saturated within 40 inches for less than 1 month per year or less than 6 out of 10 years, or both.
The O horizon has hue of 10YR or is neutral in hue. Value is 2 or 3 and chroma is 0 to 2. It is partially decomposed forest litter.
The A horizon has hue of 7.5YR or 10YR, value of 2 or 3, and chroma of 1 to 3. Some pedons have an Ap horizon with hue of 7.5YR or 10YR, value of 3 or 4, and chroma of 2 or 3..
The E horizon has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 2 or 3. Colors of 4/3 or 5/3 have value dry of 7 or more. The E horizon is sand or coarse sand.
The Bs horizon has hue of 5YR value of 3 to 6, and chroma of 4 to 6 or hue of 7.5YR, value of 3 to 5 and chroma of 4. It is sand or coarse sand.
The Bw or BC horizon has hue of 7.5YR or 10YR, value of 4 or 6, and chroma of 4 to 8. It is sand or coarse sand. Bw or BC horizons with spodic color have pH greater than 5.9 or have less than 0.6 percent organic carbon.
The C horizon has hue of 7.5YR or 10YR, value of 4 to 7, and chroma of 2 to 8. It is sand or coarse sand.
COMPETING SERIES: This is the Arbutus series. Similar soils are the Croswell, Friendship, and Halfaday series. Arbutus soils have a lithic contact of igneous or metamorphic bedrock at 20 to 40 inches and do not have a water table. Croswell, Friendship, and Halfaday soils have mixed mineralogy. In addition, Friendship soils do not have a spodic horizon and Halfaday soils have a Bhs horizon.
GEOGRAPHIC SETTING: Rockdam soils are on pediments and stream terraces. Slope gradients range from 0 to 3 percent. These soils formed in siliceous sandy alluvium or residuum. Mean annual precipitation ranges from 28 to 33 inches. Mean annual temperature ranges from 39 to 45 degrees F. The frost free period ranges from about 90 to 135 days. Elevation ranges from 800 to 1400 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fairchild, Ironrun, Ludington, and Ponycreek soils. The somewhat poorly drained Ironrun soils and the poorly drained Ponycreek soils form a drainage sequence with the Rockdam soils. The somewhat poorly drained Fairchild soils and the moderately well drained Ludington soils form a drainage sequence in nearby areas where the siliceous sand is underlain by interbedded sandstone and shale at 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Moderately well drained. Surface runoff is slow. Permeability is rapid or very rapid. These soils have an apparent seasonal high water table at a depth of 3.5 to 6 feet For 1 month or more per year at some time from November to May in 6 or more out of 10 years.
USE AND VEGETATION: Most areas of this soil are used for woodland. Native vegetation is mixed deciduous and coniferous forest with some grass in the understory. Common trees are jack pine, northern pin oak, and eastern white pine. Some areas are used for cropland. Common crops are corn, small grain, and hay. Some areas are used for pastureland.
DISTRIBUTION AND EXTENT: West Central Wisconsin. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Clark County, Wisconsin, 1994.
REMARKS: Diagnostic horizons and features recognized in this soil: ochric epipedon - 1 to 6 inches (A,E); albic horizon - 3 to 6 inches (E); spodic horizon - 6 to 19 inches (Bs1, Bs2); siliceous mineralogy - have less than 10 percent weatherable minerals in the particle-size control section.
ADDITIONAL DATA: Soil Interpretation Record - WI0435