LOCATION OLMSTEAD ARTentative Series
TAXONOMIC CLASS: Fine-silty, mixed, semiactive, thermic Typic Epiaqualfs
TYPICAL PEDON: Olmstead silt loam, 0 to 2 percent slopes in an area of willow oaks. (Colors are for moist soil unless otherwise stated.)
A--0 to 3 inches; brown (10YR 5/3) silt loam; moderate fine granular and weak medium subangular blocky structure; friable; many fine roots; common fine, few medium and few coarse pores; few fine prominent strong brown (7.5YR 5/6) masses of iron accumulation in matrix and lining some pores; extremely acid; clear smooth boundary.
Eg1--3 to 9 inches; light brownish gray (10YR 6/2) silt loam; weak medium and coarse subangular blocky structure; friable; common fine and common medium roots; few fine pores; common fine faint light gray (10YR 7/2) clay depletions in matrix; many medium and coarse distinct brownish yellow (10YR 6/6) masses of iron accumulation in matrix; common medium prominent strong brown (7.5YR 5/6) masses of iron accumulation on faces of peds; extremely acid; clear smooth boundary.
Eg2--9 to 18 inches; light brownish gray (10YR 6/2) silt loam; weak medium and coarse subangular blocky structure; friable; few fine and common medium roots; many fine, common medium and few coarse pores; common medium and coarse faint light gray (10YR 7/2) clay depletions on faces of peds; many medium and coarse brownish yellow (10YR 6/6) masses of iron accumulation in matrix; few medium strong brown (7.5YR 5/6) masses of iron accumulation on faces of peds; few fine and medium brown (7.5YR 4/4) iron concretions throughout; extremely acid; gradual smooth boundary.
Btg1--18 to 35 inches; light brownish gray (10YR 6/2) silty clay loam; moderate medium and coarse subangular blocky structure; few fine and few medium roots; firm; many fine, common medium and few coarse pores; few distinct yellowish brown (10YR 5/6) clay films on faces of peds and on surfaces along pores, few faint grayish brown (10YR 5/2) clay films on surfaces along some pores and few distinct reddish brown (5YR 4/4) clay films on surfaces along some pores; common medium and coarse faint light gray (10YR 7/2) clay depletions throughout matrix; few medium prominent reddish yellow (7.5YR 6/6), and common medium and coarse prominent brownish yellow (10YR 6/6) masses of iron accumulation in matrix; few medium faint gray (10YR 5/1) iron depletions in matrix; many crayfish burrows filled with gray (10YR 5/1) silt clay loam; common fine and medium yellowish red (5YR 4/6) soft iron concretions; few fine and medium hard iron-manganese concretions with brown exteriors and black interiors; very strongly acid; clear irregular boundary.
2Bt--35 to 48 inches; brownish yellow (10YR 6/6) silt loam; weak coarse subangular blocky structure; very firm; some peds slightly brittle; few fine and medium roots following crayfish burrows; common fine, few medium and few coarse pores; most medium and coarse pores filled with brown (7.5YR 4/4) clay films and some with reddish brown (5YR 4/4) and brown (10YR 5/3) clay films on surfaces along pores; few fine and medium distinct light gray (10YR 7/2) clay depletions throughout; few fine and medium faint dark yellowish brown (10YR 4/6) masses of iron accumulation on faces of peds; common fine and medium distinct dark yellowish brown (10YR 4/4) masses of iron accumulation in matrix; many medium and coarse distinct light brownish gray (10YR 6/2) iron depletions in matrix; few fine prominent black (10YR 2/1) soft masses of manganese accumulation on surfaces along pores; crayfish burrows filled with gray (10YR 5/1) silt clay loam; common medium and coarse yellowish red (5YR 4/6) soft iron concretions; very strongly acid; gradual wavy boundary.
2Btg1--48 to 64 inches; grayish brown (10YR 5/2) silt loam; weak coarse subangular blocky structure; very firm with some peds slightly brittle; few fine roots following old gray crayfish burrows; many fine; many medium and few coarse pores; most pores filled with distinct reddish brown (5YR 4/4) clay films; few distinct grayish brown (10YR 5/2) clay films on surfaces along some pores; common fine and medium faint light gray (10YR 7/2) clay depletions throughout; many fine and medium prominent yellowish brown (10YR 5/6), and common fine and medium distinct dark yellowish brown (10YR 4/4) soft masses of iron accumulation in matrix; many fine and medium yellowish brown (10YR 5/6 and 5/8) soft iron concretions throughout; common fine and medium faint gray (10YR 5/1) iron depletions lining pores and on faces of peds; common crayfish burrows and channels filled with gray (10YR 5/1) silty clay loam; burrows have common light gray (10YR 7/1) clay depletions; burrows have common fine yellowish brown (10YR 5/4) iron accumulations inside channels; very strongly acid; gradual smooth boundary.
2Btg2--64 to 80 inches; light brownish gray (10YR 6/2) silt loam; weak coarse subangular blocky structure; very firm with some peds slightly brittle; few medium roots; many fine, common medium and few coarse pores; few distinct dark yellowish brown (10YR 4/6) clay films on some faces of peds; some medium and coarse pores are lined with reddish brown (5YR 4/4) prominent clay films; some pores lined with yellowish brown (10YR 5/4) clay films; common fine and medium faint light gray (10YR 7/2) clay depletions; common fine distinct dark yellowish brown (10YR 4/4) masses of iron accumulations in matrix; common fine prominent yellowish brown (10YR 5/6) iron accumulations in matrix and lining some pores; common fine and medium grayish brown (10YR 5/2) iron accumulations lining pores and on faces of peds; common fine dark yellowish brown (10YR 4/4) and yellowish brown (10YR 5/6) soft iron concretions throughout; several crayfish burrows up to 3 inches in diameter filled with gray (10YR 5/1) silty clay loam; common crayfish burrows and channels filled with gray (10YR 5/1) silt clay loam; burrows have a common light gray (10YR 7/1) clay depletions; very strongly acid.
TYPE LOCATION: Faulkner County, Arkansas; east on Arkansas Highway 89 from intersection of US. Interstate 40, south approximately 2 miles on Clinton (Little Rock) Road into Camp Robinson, east on dim road approximately 1000 feet then 200 feet north; SE1/4NE1/4SW1/4NE1/4 Sec. 31, T.4N., R.12W; lat. 92 degrees, 19 minutes, 27 second, long. 34 degrees, 56 minutes, 16 seconds, Cato Quadrangle.
RANGE IN CHARACTERISTICS: Solum thickness is greater than 60 inches. Depth to shale bedrock is greater than 60 inches. Reaction ranges from very strongly acid to extremely acid throughout. Sandstone fragments less than 3 inches in diameter range from 0 to 5 percent.
The A horizon has hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 1 to 3, with iron accumulations in shades of red and brown. Texture is silt loam.
The Eg horizon has hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 1 or 2, with iron accumulations in shades of brown and yellow. Texture is silt loam.
The Btg horizon has hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 1 or 2, with iron accumulations in shades of brown and yellow. Texture is silt loam.
The Bt horizon has hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 3 to 6, with iron accumulations in shades of brown and yellow and gray. Texture is silt loam or silty clay loam.
The 2Bt horizon has hue of 10YR or 2.5Y, value of 5 or 6 and chroma of 1 or 2 with iron accumulations in shades of brown and yellow. Texture is silty clay loam, clay loam, silty clay or clay. Some pedons will have less than 30 percent brittleness.
The 3Cr horizon, when present, The 3Cr horizon is soft weathered shale bedrock in various shades of black, olive, gray, brown, red and yellow. The beds have a dip of more than 20 degrees from horizontal.
COMPETING SERIES: Olmstead is the only series in this family.
GEOGRAPHIC SETTING: Olmstead soils are on level and concave depressions and drainageways within valleys of the Ouachita Mountains. Slopes range from 0 to 2 percent slopes. Some areas have numerous mounds. These soils formed in fluvial deposition from nearby hillsides which was deposited on top of predominately tilted, fractured and folded shale bedrock. In most pedons a paleosol is present. Mean annual precipitation ranges from 41 to 56 inches with the highest amount being destributed in January to May. Mean annual temperature ranges from 60 degrees to 64 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cato, Maumelle, and Psyam soils. The Cato and Psyam soils are on slightly higher landscape. The Maumelle soils are on slightly lower landscapes and are poorly drained.
DRAINAGE AND PERMEABILITY: Olmstead soils are somewhat poorly drained. Runoff is low. Permeability is moderately slow.
USE AND VEGETATION: Water oaks, willow oaks and sweet gum.
DISTRIBUTION AND EXTENT: Ouachita Mountains of Arkansas and possibly Oklahoma; MLRA 119. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES PROPOSED: Faulkner County, Arkansas; 1998
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil
surface to a depth of about 2 inches.
Argillic horizon - the zone from a depth of
about 8 inches to 73 inches.
Paralithic contact - boundary between the 2Bt
horizon and the underlying soft shale bedrock (Cr).
ADDITIONAL DATA: Characterization of the typical pedon by the University of Arkansas Soil Characterization Laboratory, NRCS sample number S98AR045-07-(1-7).