LOCATION MAGNET AR
Established Series
JEH:ALW:LBW
04/2022
MAGNET SERIES
The Magnet series consists of moderately deep, well drained, moderately slowly permeable soils that formed in residuum from syenite and other intrusive igneous rocks. These soils are on ridgetops, side slopes, and foot slopes of a ring dike complex in the Ouachita Mountains. Slopes range from 3 to 40 percent. Mean annual temperature is about 62 degrees F and mean annual precipitation is about 52 inches.
TAXONOMIC CLASS: Fine, mixed, active, thermic Ultic Hapludalfs
TYPICAL PEDON: Magnet loam, 5 percent slope in a moist idle field. (Colors are for moist soil.)
Ap--0 to 4 inches; dark reddish brown (5YR 3/4) loam; moderate fine granular structure; friable; many fine roots; about 5 percent by volume of subrounded cobbles and gravel; strongly acid; clear smooth boundary. (3 to 6 inches thick)
A--4 to 8 inches; dark reddish brown (5YR 3/4) loam; weak medium subangular blocky structure; friable; common fine roots; about 5 percent by volume of subrounded cobbles and gravel; strongly acid; gradual smooth boundary. (0 to 6 inches thick)
Bt1--8 to 23 inches; reddish brown (5YR 4/4) clay; moderate medium subangular blocky structure; firm; thin continuous clay films on faces of peds; few fine roots; about 5 percent by volume of subrounded cobbles and gravel; slightly acid; gradual smooth boundary.
Bt2--23 to 31 inches; about 75 percent reddish brown (5YR 4/3) clay loam; strong medium subangular blocky structure; firm; thin continuous clay films on faces of peds; 2 to 4 inch wide wedge
shaped vertical seams in which peds are coated with dark stains; about 5 percent by volume of subrounded cobbles and gravel; strongly acid; abrupt irregular boundary; about 25 percent of mass is soft, multicolored syenitic saprolite in small irregular shaped pockets. (Combined thickness of Bt horizon is 17 to 38 inches.)
Cr/Bt--31 to 72 inches; about 85 percent soft, multicolored syenitic saprolite; about 15 percent of mass is soil in seams about 2 inches wide and 24 inches apart; the soil is reddish brown (5YR 4/3) clay loam, weak medium subangular blocky structure; firm; thin continuous clay films on faces of peds; strongly acid.
TYPE LOCATION: Hot Spring County, Arkansas; 2.5 miles northwest of Magnet Cove school in the SW1/4NW1/4NW1/1/4, sec. 17., T. 3 S., R. 17 W.
RANGE IN CHARACTERISTICS: Solum thickness and depth to soft, weathered bedrock ranges from 20 to 50 inches and is extremely variable in short distances. Depth to hard bedrock is more than
60 inches. Reaction ranges from slightly acid to strongly acid throughout. Coarse fragment content ranges from 0 to 30 percent throughout.
The A horizon has hue of 7.5YR, value of 3 to 4, and chroma of 2 or 4 or it has hue of 5YR, value of 3 or 4, and chroma of 2, 3, or 4. Texture is loam or stony loam. A horizons with value and chroma of 3 or less, are less than 6 inches thick.
The Bt horizon has hue of 5YR, value of 4 or 5, and chroma of 3 to 6 or it has hue of 2.5YR, value of 4 or 5, and chroma of 4 or 6. Texture is silty clay loam, silty clay, clay, or clay loam; or their gravelly or cobbly analogs. The upper 20 inches of the argillic horizon or to the paralithic contact averages 35 to 55 percent clay.
The Cr horizon is extremely variable over short distances. Dominantly, it is soft, multi-colored syenitic saprolite and other igneous rocks of variable mineral composition.
COMPETING SERIES: These include
Brantley,
Canton Bend,
Capshaw,
Enon,
Gundy,
Hallsummit,
Hampshire,
Maben,
Mecklenburg,
Spray, and
Zion series in the same family and
Barnsdall,
Lenberg,
Needmore,
Sandhill, and
Toine series in closely related families.
Brantley and
Canton Bend soils contain mica flakes, generally have thicker sola, and lack a paralithic contact.
Capshaw soils have brown or olive Bt horizons, contain chert fragments, and are underlain by hard limestone.
Enon soils have hue of 7.5YR or yellower in the Bt horizon and are underlain by shale saprolite.
Gundy soils have 20 to 40 inches sola and are underlain by slate.
Hampshire soils have hue of 7.5YR or yellower in Bt horizon and are underlain by shale and linestone.
Maben soils contain mica flakes in the solum and are underlain by shale rich in mica.
Mecklenburg soils are slowly permeable and are underlain by saprolite of mafic rocks.
Hallsummit soils have sola more than 60 inches thick and contain ironstone and mica flakes.
Spray soils have 10 to 20 inches sola and are underlain partially weathered shale.
Zion soils have 20 to 40 inches sola and underlain by hard bedrock.
Barnsdall soils are fine-silty.
Lenberg and Needmore soils are mesic. Sandhill and Toine soils are fine-loamy.
GEOGRAPHIC SETTING: Magnet soils are on gently sloping foot slopes and steep side slopes and ridges of a ring dike complex in the Ouachita Mountains. The dike complex consists of three
roughly concentric rings. Slope ranges from 3 to 40 percent. These soils formed principally in syenitic saprolite. 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: There are no other soils recognized inside the dike complex. Associated soils outside the dike are
Bismarck,
Carnasaw,
Pirum,
Sherless, and Sherwood.
Bismark soils, which are on adjacent valley floors and lower side slopes, are loamy-skeletal and less than 20 inches deep to weathered shale bedrock.
Carnasaw soils, which are on side slopes have clayey Bt horizons and are 40 to 60 inches deep over shale bedrock.
Pirum and
Sherwood soils, which are on adjacent ridgetops and side slopes, are fine-loamy over hard sandstone.
Sherless soils, which are on adjacent valley floors, side slopes, and low ridges are fine-loamy over soft sandstone.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff and moderately slow permeability.
USE AND VEGETATION: Chiefly used for forestry and pasture. Native trees are upland oaks, shortleaf pine, and eastern red cedar. Most of the gently sloping to moderately steep areas have been cleared and are used for pasture.
DISTRIBUTION AND EXTENT: Ouachita Mountains of Arkansas. The series is of small extent, less than 5,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES PROPOSED: Hot Spring County, Arkansas; 1982.
REMARKS: ADDITIONAL DATA: S81-A R-059-1 (1-6)
National Cooperative Soil Survey
U.S.A.