LOCATION MARGO VAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, semiactive, thermic Aquic Hapludults
TYPICAL PEDON: Margo loam-on a 2 percent concave slope along a drainageway in a mixed hardwood and pine forest. (Colors are for moist soil.)
01--3 to 0 cm; undecomposed and partially decomposed leaves and twigs.
A1--0 to 3 cm; very dark grayish brown (10YR3/2) loam; moderate fine granular sturcture; very friable; many fine and medium roots;
2 percent angular quartz pebbles; few very fine flakes of mica;
very strongly acid; clear smooth boundary. (3 to 10 cm thick)
A2--3 to 23 cm; light yellowish brown (10YR6/4) loam; moderate fine granular structure; very friable; many fine and medium roots;
2 percent angular quartz pebbles; few very fine flakes of mica;
very strongly acid; clear smooth boundary. (15 to 35 cm thick)
B21t--23 to 43 cm; yellowish brown (10YR5/6) loam; weak fine and medium subangular blocky structure; friable, slightly plastic;
many fine roots; 1 percent angular quartz pebbles; few thin clay films on faces of peds; many very fine flakes of mica; very
strongly acid; gradual smooth boundary.
B22t--43 to 80 cm; light olive brown (2.5Y5/6) clay loam, many fine and medium distinct light brownish gray (10YR6/2) mottles; friable, slightly sticky, slightly plastic; common thin clay films and silt coatings on faces of peds; 1 percent angular quartz
pebbles; many very fine flakes of mica; strongly acid; clear
smooth boundary.
B23t--80 to 107 cm; light olive brown (2.5Y5/6) clay loam; common medium and coarse prominent light gray (10YR6/1) mottles; moderate medium subangular blocky structure; friable, slightly sticky, slightly plastic; common thin clay films and silt coatings on
faces of peds; 1 percent angular quartz pebbles; many very fine flakes of mica; strongly acid; abrupt smooth boundary.
B24t--107 to 114 cm; light olive brown (2.5Y5/6) gravelly clay loam; common medium and coarse prominent light gray (10YR6/1) mottles; moderate medium subangular blocky structure; friable, slightly sticky, slightly plastic; common thin clay films and silt coatings on faces of peds and coarse fragments; 20 percent angular quartz pebbles; many very fine mica flakes; strongly acid; abrupt smooth boundary. (Combined thickness of the B2t horizon is 60 to
140 cm)
IIC--114 to 150 cm; brownish yellow (10YR6/6) sandy loam; many medium and coarse red (2.5Y5/8) and gray (10YR5/1) mottles;
massive; very friable; few the clay flows in the upper part; many fine and very fine mica flakes; strongly acid.
TYPE LOCATION: Spotsylvania County, Virginia; 2.8 km west of Lanes Corner at junction of Highways 208 and 659; about 65 meters west
of Highway 659.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 75 to 150 cm. Depth to hard bedrock is greater than 180 cm. Coarse fragments
range from 0 to 5 percent in the A horizon, all parts of the B2t horizon except the deepest subhorizon, and from 0 to 35 percent in the deepest subhorizon, and 0 to 15 percent in the C horizon. The
C horizon of some pedons contain partly weathered fragments of
mica schist. The soil is strongly acid or very strongly acid, throughout, unless limed.
The A horizon has hue of 7.5YR through 2.5Y, value of 2 through 7, and chroma of 2 through 4. It is loam or silt loam.
The B2t horizon has hue of 7.5YR through 2.5Y, value of 5 through
7, and chroma of 3 through 8. Some mottles in the upper part of
the B2t horizon have chroma of 2 or less. In some pedons the
lower part of the B2t horizon is dominantly gray. The B2t horizon
is loam, silt loam, silty clay loam, or clay loam and includes individual subhorizons of sandy loam or sandy clay loam. The
deepest B2t horizons may be gravelly.
The C horizon is mostly residuum of weathered mica schist. In
some places the upper part of the C horizon is in alluvial or colluvial material. It is multicolor and commonly contains shades
of red, yellow, brown, and gray. Generally, it does not have a dominant color. It is sandy loam, loam, silt loam, clay loam, or silty clay loam. Sandier textures are the result of sandsize
flakes of mica.
COMPETING SERIES: There are no other known soils in this family. Similar soils are
Berea,
Mattapex, and
Morehead series. These
soils have average annual temperature of less than 15 degrees C.
GEOGRAPHIC SETTING: Margo soils are dominantly in depressions, along drainageways, and on toe slopes in the Piedmont Province. They
also occur on terraces in the Coastal Plain in sediments washed
from the Piedmont. Slopes are commonly concave and range in
gradient from 0 to 7 percent. These soils formed in alluvial and colluvial material underlain by weathered mica schist or Coastal Plain sediments at depth of 50 to 130 cm.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Brockroad,
Catharpin,
LaRoque,
Nason,
Tatum, and
Toddstav soils. The Brockroad,
Catharpin, Nason, and Tatum soils are better drained, have higher clay content in their subsoils, and are on higher landscape positions. LaRoque soils are better drained and are on higher landscape positions. The Toddstav soils are poorly drained.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is slow to medium. Permeability is moderate.
USE AND VEGETATION: Most of the Margo soils are in mixed hardwood and pine forest. The remainder is mostly cropland or pasture. Native vegetation was hardwood forest.
DISTRIBUTION AND EXTENT: Margo soils are not extensive. This series is thought to occur on the southern Piedmont Province of Virginia
and North Carolina.
MLRA OFFICE RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: Spotsylvania County, Virginia, 1980. Source of name is the village of Margo in Spotsylvania County, Virginia.
REMARKS: Margo soils were included with the Abell soils in the
past. Laboratory data from 5 pedons in Spotsylvania County by Virginia Polytechnic Institute verify the classification.
TABULAR SERIES DATA:
SOI-5 Soil Name Slope Airtemp FrFr/Seas Precip Elevation VA0120 MARGO 0- 7 59- 63 180-200 38- 45 300- 900SOI-5 FloodL FloodH Watertable Kind Months Bedrock Hardness VA0120 FREQ 1.0-3.0 APPARENT NOV-MAR 60-60
SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC- VA0120 0- 9 L SIL 0- 0 90-100 5-27 - VA0120 9-42 L SIL SICL 0- 0 90-100 18-35 - VA0120 42-45 GR-L GR-SIL GR-SICL 0- 0 50- 75 5-40 - VA0120 45-60 SL L SICL 0- 0 90-100 5-40 -
SOI-5 Depth -pH- O.M. Salin Permeab Shnk-Swll VA0120 0- 9 4.5- 5.5 1.-3. 0- 0 2.0- 6.0 LOW VA0120 9-42 4.5- 5.5 0.-.5 0- 0 0.6- 2.0 MODERATE VA0120 42-45 4.5- 5.5 0.-.5 0- 0 0.6- 2.0 MODERATE VA0120 45-60 4.5- 5.5 0.-.5 0- 0 0.6- 2.0 MODERATE