LOCATION PSYAM ARTentative Series
TAXONOMIC CLASS: Fine-silty, mixed, semiactive, thermic Oxyaquic Hapludalfs
TYPICAL PEDON: Psyam silt loam, forested
(Colors are for moist soil unless otherwise stated.)
A--0 to 2 inches; yellowish brown (10YR 5/4) silt loam; moderate fine granular and weak medium subangular blocky structure; friable; many fine roots; many fine pores; common fine faint brown (7.5YR 4/4) masses of iron accumulation around root channels; occasional subrounded sandstone fragment less than 3 inches diameter; extremely acid; clear smooth boundary.
BA--2 to 10 inches; light yellowish brown (2.5Y 6/4) silt loam; weak coarse subangular blocky structure; friable; common fine, common medium, and few coarse roots; common fine, common medium, and few coarse pores; common medium distinct brownish yellow distinct (10YR 6/6), and few fine distinct yellowish brown (10YR 5/6) masses iron accumulations in matrix; few fine faint pale brown (10YR 6/3) iron depletions infused into the matrix adjacent to pores and root channels; few fine red to brown iron-manganese concretions throughout; occasional subrounded sandstone fragment less than 3 inches in diameter; extremely acid; clear smooth boundary.
Bt1--10 to 21 inches; light yellowish brown (2.5Y 6/4) silt loam; moderate medium and coarse subangular blocky structure; friable; common fine and common medium roots; common fine, common medium, and few coarse pores; common faint brown (10YR 4/3) clay films on faces of some peds; common fine and medium distinct light gray (10YR 7/1) clay depletions, which disappear on wetting, throughout; many medium distinct yellowish brown (10YR 5/6) masses of iron accumulation in matrix; few fine prominent strong brown (7.5YR 5/6) masses of iron accumulation in matrix; few fine faint pale brown (10YR 6/3) iron depletions on faces of peds and lining some pores; few fine and medium red to brown Fe-Mn concretions in matrix; occasional subrounded sandstone gravel; extremely acid; clear smooth boundary.
Bt2--21 to 30 inches; brownish yellow (10YR 6/6) silt loam; weak medium and coarse subangular blocky structure; friable; common fine and common medium roots; common fine, common medium, few coarse pores; many faint brown (10YR 4/3) clay films on faces of peds and few faint gray (10YR 5/1) clay films on surfaces along pores; many fine and medium distinct light gray (10YR 7/1) clay depletions, which disappear on wetting, throughout; few medium faint strong brown (7.5YR 5/6) masses of iron accumulations in matrix; common fine and medium prominent light brownish gray (2.5Y 6/2) iron depletions in matrix; common fine and medium prominent light yellowish brown (2.5Y 6/3) iron depletions in matrix; few fine prominent black (10YR 2/1) masses of manganese accumulation lining some pores; common fine and medium red to black iron-manganese concretions throughout; very strongly acid; gradual wavy boundary.
Bt3--30 to 40 inches; brownish yellow (10YR 6/6) silt loam; weak medium and coarse subangular blocky structure; friable; common fine and few medium roots; many fine, common medium pores; common distinct gray (10YR 6/1) and dark yellowish brown (10YR 4/4) clay films on faces of peds and on surfaces along pores; many fine, medium and coarse distinct light gray (10YR 7/1) clay depletions, which disappear on wetting, throughout; common fine and medium faint yellowish brown (10YR 5/6) masses of iron accumulation in matrix; common fine and medium prominent gray (2.5Y 6/1) iron depletions in matrix; few fine and medium red to black iron-manganese concretions throughout; few fine black (10YR 2/1) masses of manganese accumulation lining some pores; very strongly acid; clear wavy boundary.
2Btg1--40 to 51 inches; gray (2.5Y 6/1) silt clay loam; moderate medium and coarse subangular blocky structure; firm; few fine roots; common fine and few medium pores; many prominent gray (10YR 5/1) and dark yellowish brown (10YR 4/4) clay films on faces of peds and on surfaces along pores; few fine distinct light gray (10YR 7/1) clay depletions, which disappear on wetting, throughout; common medium and coarse prominent strong brown (7.5YR 5/6), common fine and medium prominent reddish yellow (5YR 6/6), and common fine and medium distinct light olive brown (2.5Y 5/3) masses of iron accumulation in matrix; few fine and medium faint gray (2.5Y 5/1) iron depletions on faces of peds and lining pores; few fine and medium prominent black (10YR 2/1) masses of manganese accumulations on faces of some peds and lining some pores; few fine and medium red to black iron-manganese concretions throughout; very strongly acid; gradual wavy boundary.
2Btg2--51 to 76 inches; light brownish gray (2.5Y 6/2) silty clay loam; weak medium and coarse subangular blocky structure; firm; few fine roots; common fine and few medium pores; many prominent gray (2.5Y 6/1) and light olive brown (2.5Y 5/3) clay films on faces of peds and along surfaces of pores; few fine and medium distinct light gray (10YR 7/1) clay depletions on faces of some peds; common medium and coarse prominent yellowish brown (10YR 5/6), and common fine and common medium faint light olive brown (2.5Y 5/3) masses of iron accumulation in matrix; common medium and coarse faint gray (2.5Y 6/1) iron depletions in matrix; common fine and medium black (10YR 2/1) masses of manganese accumulations on faces of peds and lining some pores; few fine and medium red to black iron-manganese concretions throughout; about 8% soft weathered shale channers up to 4" in length; strongly acid; clear wavy boundary.
2Cr--76-80 inches; soft weathered brown and gray shale bedrock with thin layers of light olive brown (2.5Y 5/3) and gray (2.5Y 6/1) silt loam between shale plates.
TYPE LOCATION: Pulaski County, Arkansas; NW1/4 SW1/4 NE1/4 SE1/4, sec. 9, T. 3 N., R. 12 W.; lat. 92 degrees, 17 minutes, 19 second, long. 34 degrees, 54 minutes, 22 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 in the A, and BA horizons and from moderately acid to extremely acid in the Bt and 2Bt horizons. Sandstone fragments less than 3 inches in diameter range from 0 to 5 inches in the A, BA and Bt horizons. Sandstone and shale fragments less than 3 inches in diameter and/or less than 6 inches in length range from 0 to 15 percent in the 2Btg horizon.
The A horizon has hue of 10YR, value of 4, and chroma of 2 to 4. Texture is silt loam.
The E horizon, when present, has hue of 10YR to 2.5Y, value of 5 to 6, and chroma of 2 to 4. Texture is silt loam.
The BA or BE horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 4 or 6. Texture is silt loam.
The Bt horizon has hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 4 or 6. Clay depletions are in shades of gray and iron accumulations and depletions are in shades of red, brown, yellow and gray. Texture is silt loam, silty clay loam, or clay loam.
The 2Btg horizon has hue of 10YR or 2.5Y, value of 5 or 6, and chroma 1 through 2. Clay depletions are shades of gray and iron accumulations and depletions are in shades of red, brown, yellow and gray. Texture is silty clay loam, silty clay, clay loam, or clay.
The 2Cr horizon, where present, 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: Psyam is the only series in this family.
GEOGRAPHIC SETTING: Psyam soils are on level to gently sloping toeslopes and valley floors in narrow valleys of the Ouachita Mountains. Slopes range from 0 to 8 percent. These soils formed in colluvium deposition from nearby hillsides which was deposited on top of predominately tilted, fractured, and folded shale bedrock . In some pedons, a paleosol is present. Mean annual precipitation ranges from 41 to 56 inches with the highes amount being distributed in January to May. Mean annual temperature ranges from 60 degrees to 64 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cato and Olmstead soils. The Cato soils are on similar landscapes and are shallower to shale. The Olmstead soils are on slightly lower landscapes and are somewhat poorly drained.
DRAINAGE AND PERMEABILITY: Psyam soils are moderately well drained. Runoff is low to medium depending on slope. Permeability is moderately slow.
USE AND VEGETATION: Used mainly for pasture and native woodland. Common pasture plants include common burmudagrass and tall fescue. Native forest vegetation was post oaks, blackjack oak, southern red oak, hickory and shortleaf pine.
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: Pulaski 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 10 inches to 76 inches.
Paralithic contact - boundary between the 2Bt2
horizon and the underlying soft shale bedrock (Cr).
These soils were formerly included in the Leadvale series.
ADDITIONAL DATA: Characterization of the typical pedon by the University of Arkansas Soil Characterization Laboratory, NRCS sample No. S98AR119-01-(1-7)