LOCATION ARKANA AR+MO
Established Series
Rev. LBW/RLT
11/2021
ARKANA SERIES
The Arkana series consists of moderately deep, well drained soils that formed in gravelly colluvium and the underlying clayey residuum weathered from limestone or dolomite. These soils are on gently sloping to steep uplands of the Ozark Highlands. Slopes range from 3 to 40 percent. The mean annual temperature is about 58 degrees F., and the mean annual precipitation is about 45 inches.
TAXONOMIC CLASS: Very-fine, mixed, active, mesic Mollic Hapludalfs
TYPICAL PEDON: Arkana very gravelly silt loam, on a smooth 5 percent slope, in woodland. (Colors are for moist soil unless otherwise stated.)
Oi--0 to 1 inch; hardwood leaves and twigs.
A1--1 to 4 inches; very dark grayish brown (10YR 3/2) very gravelly silt loam; weak fine granular structure; friable; about 45 percent angular chert gravel; many fine and medium roots; many fine pores; moderately acid; clear wavy boundary. (3 to 8 inches thick)
A2--4 to 8 inches; dark brown (10YR 3/3) very gravelly silt loam; moderate medium granular structure; friable; about 45 percent angular chert gravel; many fine and medium roots; many fine pores; strongly acid; abrupt wavy boundary. (0 to 5 inches thick)
E--8 to 12 inches; brown (10YR 4/3) very gravelly silt loam; moderate medium granular structure; friable; 55 percent angular chert gravel; many fine and medium roots; common fine pores; strongly acid; clear wavy boundary. (0 to 8 inches thick)
BE--12 to 16 inches; yellowish red (5YR 4/6) very gravelly silt loam; moderate medium subangular blocky structure; firm; about 50 percent angular chert gravel; common fine roots; common fine pores; strongly acid; clear wavy boundary. (0 to 6 inches thick)
Bt1--16 to 22 inches; yellowish red (5YR 5/6) gravelly clay; few fine distinct yellowish brown mottles; moderate fine subangular blocky structure; firm; plastic; about 30 percent angular chert gravel; many distinct clay films on faces of peds; few fine roots; few fine pores; few fine dark brown manganese concretions; very strongly acid; clear wavy boundary.
2Bt2--22 to 28 inches; dark yellowish brown (10YR 4/4) clay; moderate medium and coarse blocky structure; very firm; plastic; about 10 percent angular chert gravel; many distinct clay films on faces of peds; few fine roots; few fine pores; few fine dark brown manganese concretions; strongly acid; abrupt smooth boundary. (Combined thickness of the Bt horizon is 11 to 24 inches thick)
2R--28 inches; hard, level-bedded dolomite; more than 4 inches between cracks.
TYPE LOCATION: Baxter County, Arkansas; 5.2 miles northeast of Mountain Home square on Highway 62 then 1.8 miles north on Cranfield Road then 150 feet west in NW1/4SE1/4SE1/4 sec. 13, T. 20 N., R. 13 W.
RANGE IN CHARACTERISTICS: Solum thickness and depth to bedrock ranges from 20 to 45 inches. Reaction of the A, E, and BE horizons range from very strongly acid to neutral. The Bt and 2Bt horizons also range from very strongly acid to neutral, but can be mildly alkaline in the layer immediately above bedrock. Rock fragment content ranges from 10 to 60 percent in the A and E horizons; 15 to 60 percent in the BE horizon, and 0 to 40 percent in the Bt and 2Bt horizons. The particle-size control section has a weighted average of 60 to 85 percent clay, and 0 to 35 percent rock fragments.
The A horizon has hue of 10YR, value of 2 or 3, and chroma of 1 to 3. It is silt loam, silty clay loam, or their gravelly or very gravelly analogs.
The E horizon has hue of 10YR, value of 4 to 6, and chroma of 2 to 4. It is silt loam or loam, or their gravelly or very gravelly analogs.
The BE horizon has hue of 5YR or 7.5YR, value of 5, and chroma of 4 to 8, or value of 4 and chroma of 4 to 6. Mottles are in shades of brown. It is gravelly silt loam, gravelly loam, gravelly silty clay loam, or their very gravelly analogs.
The Bt1 or 2Bt horizon has hue of 2.5YR to 10YR, value of 4 to 6, and chroma of 4 to 8. Texture is silty clay loam, silty clay, clay or their gravelly analogs.
The Bt2 or 2Bt2 horizon has hue of 2.5YR to 10YR, value of 5, and chroma of 4 to 8, or value of 4, and chroma of 4 to 6. It is typically clay or gravelly clay, but can be silty clay in the layer immediately above bedrock. Mottles are in shades of brown or red.
The R horizon is hard, level-bedded to undulating, dolomite or limestone.
COMPETING SERIES: This is the
Winneconne series. Winneconne soils have a mean annual temperature of 45 to 48 degrees F., do not have a lithic contact, and contain no rock fragments.
GEOGRAPHIC SETTING: Arkana soils are on gently sloping to steep upland ridges. They formed in gravelly colluvium and the underlying clayey residuum weathered from limestone or dolomite. Slopes range from 3 to 40 percent. Mean annual precipitation is about 42 to 50 inches and is not evenly distributed during the year. The mean annual temperature ranged from about 53 to 58 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Agnos,
Clarksville,
Doniphan,
Gassville,
Gepp,
Nixa,
Noark, and
Ventris series. Agnos soils have a lower base saturation, have a paralithic contact from 40 to 60 inches, and are on similar landscape positions. Clarksville soils are loamy-skeletal, are deeper than 60 inches to bedrock, and are at higher elevations. Doniphan soils have a lower base saturation, are deeper than 60 inches to bedrock, and are on similar landscape postions. Gassville soils have a lower base saturation, have a lithic contact from 40 to 60 inches, and are on similar landscape postions. Gepp soils have a lighter colored surface layer, are deeper than 60 inches to bedrock, and are on similar landscape postions. Nixa soils are loamy-skeletal, have a fragipan, and are at higher elevations. Noark soil are clayey-skeletal, are deeper than 60 inches to bedrock, and are at higher elevations. Ventris soils have an abrupt textural change, and are on similar landscape postions.
DRAINAGE AND PERMEABILITY: Arkana soils are well drained. Runoff potential is very high. Permeability is very slow. The saturated hydraulic conducivity is low.
USE AND VEGETATION: Most areas are forested with upland oaks and Eastern red cedar. Some areas are cleared and used for grassland or urban development. Tame grasses are mainly tall fescue.
DISTRIBUTION AND EXTENT: Ozark Highlands (MLRA 116A) in Arkansas and Missouri. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Randolph County, Arkansas; 1975.
REMARKS: These soils were previously mapped with the Corydon series in Arkansas. Diagnostic horizons and features recognized in this pedon are:
1) Ochric epipedon - the zone from the surface to a depth of 16 inches (Oi, A1, A2, E, and BE horizons)
2) Argillic horizon - the zone from 16 to 28 inches
3) Lithic contact - bedrock at 28 inches
ADDITIONAL DATA: Characterization data is available from the University of Arkansas Soil Characterization Laboratory on the typical pedon.
These soils are mapped in the Boone limestone, Cotter dolomite, and the Jefferson City dolomite formations in Arkansas and Missouri.
National Cooperative Soil Survey
U.S.A.