LOCATION BISMARCK AREstablished Series
The Bismarck series consists of shallow, somewhat excessively drained, moderately permeable soils that formed in residuum from tilted and folded shale bedrock with thin strata of interbedded sandstone, chert, and novaculite. These nearly level to very steep soils are on uplands of the Ouachita Mountains: MLRA 119. Slopes range from 1 to 60 percent. Mean annual temperature is about 62 degrees F, and the mean annual precipitation is about 52 inches.
TAXONOMIC CLASS: Loamy-skeletal, mixed, semiactive, thermic, shallow Typic Dystrudepts
TYPICAL PEDON: Bismarck very channery silt loam, 12 percent slope, pasture. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 3 inches; dark brown (10YR 3/3) very channery silt loam; moderate medium granular structure; friable; common fine and medium roots; about 45 percent by volume shale fragments less than 3 inches in diameter, about 3 percent by volume sandstone cobbles 3 to 6 inches in diameter on surface; strongly acid; clear smooth boundary. (2 to 5 inches thick)
E--3 to 7 inches; brown (10YR 4/3) very channery silt loam; weak medium subangular blocky structure; friable; common fine and medium roots; about 55 percent by volume shale fragments less than 3 inches in diameter; very strongly acid; clear smooth boundary. (3 to 7 inches thick)
Bw--7 to 14 inches; yellowish brown (10YR 5/4) extremely channery silt loam; weak medium subangular blocky structure; friable; few fine roots; about 75 percent by volume shale fragments less than 3 inches in diameter; very strongly acid; abrupt irregular boundary. (5 to 12 inches thick)
Cr--14 to 20 inches; very dark gray, brown, and red weakly cemented, fractured, acid shale containing less than 5 percent yellowish brown (10YR 5/4) silt loam as coatings on shale fragments. Shale beds have a dip of about 50 degrees from horizontal.
TYPE LOCATION: Hot Spring County, Arkansas; 1.8 miles northeast on Arkansas Highway 171 from junction with U.S. Highway 270, then 100 feet north on road in the SE1/4SE1/4NE1/4, sec. 11, T. 3 S., R. 18 W.
RANGE IN CHARACTERISTICS: Solum thickness and depth to shale ranges from 10 to 20 inches. Reaction ranges from medium acid to very strongly acid throughout.
The A horizon has hue of 10YR, value of 3 or 4, and chroma of 2, 3, or 4; hue of 7.5YR, value of 3 or 4, and chroma of 2 or 4. Texture is shaly silt loam, shaly loam, very shaly silt loam, very shaly loam and their channery, very channery, gravelly, very gravelly, cobbly and stony analogs. Shale, chert, novaculite, and sandstone fragment content ranges from 15 to 60 percent by volume.
The E horizon has hue of 10YR, value of 4, 5 or 6, and chroma of 2, 3, or 4, or hue of 7.5YR, value of 4 or 5, and chroma of 4. Texture is shaly silt loam, shaly loam, or their very shaly, channery, very channery, gravelly, and very gravelly analogs. Shale, chert, novaculite, and sandstone fragment content ranges from 15 to 60 percent by volume.
The Bw horizon has hue of 10YR, 7.5YR, or 5YR, value of 4 to 6, and chroma of 4 or 6. Texture is very shaly silt loam, very shaly loam or their extremely shaly, very channery and extremely channery analogs. Shale and sandstone fragment content ranges from 35 to 85 percent by volume.
The Cr horizon is gray, brown, yellow, and red, soft, weakly cemented, acid shale with few thin strata of interbedded sandstone and siltstone. Fines are less than 5 percent
of volume. Beds are fractured and dip ranges from 35 degrees to near vertical. Hardness of this material on Mohs' scale ranges from 1.5 to 3.0. May contain seams or pockets of soil material.
COMPETING SERIES: There are no known series in the same family. Cataska, Clebit, Goldston, Manteo, Montevallo, Nashoba, Petros, and Pickens series are in closely related families. Cataska and Petros soils have mean annual soil temperatures of less than 59 F. Goldston soils are in a siliceous mineralogy class. Manteo, Pickens, and Clebit soils have lithic contact at 20 inches or less. Montevallo soils have Cr horizons of siltstone, or silty shale with dip of less than 35 degrees. In addition, Clebit soils are in a siliceous mineralogy class. Nashoba soils have 20 to 40 inch sola.
GEOGRAPHIC SETTING: Bismarck soils are on nearly level valley floors to very steep side slopes of the Ouachita Mountains. Slopes range from 1 to 60 percent. These soils formed in residuum from tilted, fractured shale containing a few thin strata of sandstone and siltstone. The climate is warm and humid near the type location. The mean annual temperature ranges from 59 to 63 degrees F., and the annual precipitation ranges from 50 to 56 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Avant, Bengal, Bigfork, Carnasaw, Clebit, Littlefir, Mazarn, Mena, Nashoba, Pirum, Sherless, Sherwood, and Yanush series. Avant and Bigfork soils formed in chert residuum, have an argillic horizon, and are on similar and nearby landscapes. Bengal soils, which are on similar landscapes, are 20 to 40 inches deep to soft bedrock. Carnasaw soils, which are on adjacent similar landscapes, are 40 to 60 inches deep over soft bedrock and have an argillic horizon. Clebit soils formed in sandstone residuum, are 10 to 20 inches to hard bedrock, and are on nearby landscapes. Littlefir soils are 20 to 50 inches deep to shale or interbedded shale and sandstone, have an argillic horizon, and are on nearby landscapes. Marzarn soils formed in loamy sediments on adjacent drainageways and intermittent streams. Mena soils formed in pedisediments and old alluvium on adjacent valleys. Nashoba soils have siliceous mineralogy, formed in sandstone residuum, and are on nearby landscapes. Pirum soils, which are on adjacent upland sideslopes, are 22 to 50 inches deep over hard sandstone bedrock and contain less coarse fragments. Sherless soils, which are on adjacent similar landscapes, are 20 to 40 inches deep over soft sandstone bedrock and contain less coarse fragments. Sherwood soils, which are on similar upland sideslopes, are 30 to 60 inches deep over hard sandstone bedrock and contain less coarse fragments. Yanush soils formed in loamy colluvium on colluvial positions.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: Most areas are in forest. Native trees are eastern redcedar, shortleaf pine, loblolly pine, post oak, blackjack oak, and red oak. Small acreages are used for pasture and hay.
DISTRIBUTION AND EXTENT: Ouachita Mountains of Arkansas and Oklahoma. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Hot Spring County, Arkansas; 1982.
REMARKS: Diagnostic features and horizon recognized in this pedon.
Ochric epipedon - The zone from the surface to a depth of 7 inches.
Cambic horizon - The zone from 7 to 14 inches.
Paralithic contact - The zone from 14 to 20 inches.
ADDITIONAL DATA: Characterization of the type location by the University of Arkansas Soil Characterization Laboratory, Pedon No. S82AR-059-1.