LOCATION THOMSON SC
Established Series
MLB-HEH-DTA
01/2026
THOMSON SERIES
MLRA(s): 136 (thermic part)
Soil Survey Regional Office (SSRO) Responsible: Southeast
Depth Class: Very deep
Agricultural Drainage Class: Well drained
Index Surface Runoff: Medium
Saturated Hydraulic Conductivity Class: High
Shrink-Swell Potential: Low
Landscape: Piedmont stream terraces
Landform: Ridges and side slopes
Parent Material: Loamy and sandy fluvial sediments
Slope: 0 to 10 percent
Mean Annual Air Temperature: 15 degrees C (59 degrees F)
Mean Annual Precipitation: 1219 millimeters (48 inches)
TAXONOMIC CLASS: Coarse-loamy, mixed, semiactive, thermic Ultic Hapludalfs
TYPICAL PEDON: Thomson sandy loam-cultivated. (Colors are for moist soil.)
Ap--0 to 23 centimeters (0 to 9 inches); dark yellowish brown (10YR 4/4) sandy loam; weak fine granular; very friable; many fine roots; slightly acid; abrupt smooth boundary. (15 to 30 centimeters (6 to 12 inches) thick)
Bt1--23 to 76 centimeters (9 to 30 inches); strong brown (7.5YR 4/6) sandy loam; weak fine subangular blocky structure; very friable; common fine roots; sand grains bridged and coated with clay; slightly acid; diffuse smooth boundary. (25 to 102 centimeters (10 to 40 inches) thick)
BC--76 to 150 centimeters (30 to 59 inches); strong brown (7.5YR 5/6) sandy loam; weak fine subangular blocky structure; very friable; common fine roots; slightly acid; diffuse smooth boundary. (25 to 102 centimeters (10 to 40 inches) thick)
2Bt2--150 to 180 centimeters (59 to 71 inches); yellowish red (5YR 5/8) sandy clay loam; few fine faint strong brown (7.5YR 5/8) mottles; weak fine subangular blocky structure; friable; common faint clay films on faces of peds; 2 percent fine manganese concretions; slightly acid; diffuse smooth boundary.
2Bt3--180 to 203 centimeters (71 to 80 inches); strong brown (7.5YR 5/8) sandy clay loam; many medium prominent red (2.5YR 4/8) and many medium distinct brownish yellow (10YR 6/8) mottles; weak fine subangular blocky structure; friable; common faint clay films on faces of peds; slightly acid. (Combined thickness of the 2Bt horizons is 0 to 63 centimeters (0 to 25 inches)
TYPE LOCATION: Chester County, South Carolina; about 16 miles northwest of Chester, South Carolina from the intersection of Secondary Road 307 (Cabal Road) and Secondary Road 742 (Thompson Quarters Road); about 1.1 miles west northwest on Secondary Road 742; about 2200 feet west southwest on farm road; 370 feet north; in field; USGS Lockhart, South Carolina topographic quadrangle.
Latitude--34.8175
Longitude-- -81.4692
Datum--WGS84
RANGE IN CHARACTERISTICS:
Solum Thickness: 76 to 165 centimeters (30 to 65 inches)
Depth to Bedrock: Greater than 152 centimeters (60 inches)
Depth to Seasonal High Water Table: Greater than 152 centimeters (60 inches)
Rock Fragment Content: Quartz gravel make up 0 to 5 percent of the solum and 0 to 15 percent of the C horizon in the non-flooded phase; 0 to 35 percent in the solum and 0 to 50 percent of the C horizon in the flooded phase
Soil Reaction: Moderately acid to slightly alkaline except where the surface has been limed
RANGE OF INDIVIDUAL HORIZONS:
A or Ap horizon:
Color--hue of 7.5YR to 2.5Y, value of 3 to 6, and chroma of 1 to 4. Where the value is 3 and the chroma is 1 or 2, the A horizon is less than 6 inches thick.
Texture--loamy sand, loamy fine sand, sandy loam, fine sandy loam, or loam
E horizon (if it occurs)
Color--has hue of 10YR or 2.5Y, value of 4 to 7, and chroma of 4 or 6
Texture--loamy sand, loamy fine sand, sandy loam, fine sandy loam, or loam
BA or BE horizon (if it occurs)
Color--hue of 5YR to 2.5Y, value of 4 to 7, and chroma of 3 to 6
Texture--sandy loam, fine sandy loam, or loam
Bt horizon:
Color--hue of 5YR to 10YR, value of 4 to 6, chroma of 4 to 8
Texture--sandy loam, fine sandy loam, or loam. Some pedons may have a thin subhorizon that is sandy. The lower boundary is gradual or diffuse or there is more than 50 percent fine and coarser sand in the B horizon.
BC or CB horizon (if it occurs)
Color--hue of 5YR to 10YR, value of 4 to 6, chroma of 4 to 8
Texture--loamy sand or loamy fine sand
2Bt horizon:
Color--hue of 5YR to 10YR, value of 4 to 6, chroma of 4 to 8
Texture--sandy loam, sandy clay loam, or loam
C horizon (if it occurs):
Color--hue of 7.5YR to 2.5Y, value of 4 to 7, chroma of 3 to 8
Texture (fine-earth fraction)--usually stratified and ranges from coarse sand to loamy fine sand
COMPETING SERIES:
Sekil soils-have a depth to hard bedrock of 51 to 102 centimeters (20 to 40 inches) and are on piedmont uplands
GEOGRAPHIC SETTING:
Landscape: Piedmont stream terraces
Landform: Ridges and side slopes
Elevation: 30 to 76 meters (100 to 250 feet) above mean sea level
Parent Material: Loamy and sandy fluvial sediments
Mean Annual Air Temperature: 14 to 16 degrees C (58 to 60 degrees F)
Mean Annual Precipitation: 1016 to 1270 millimeters (40 to 50 inches)
Frost Free Period: 190 to 220 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Altavista soils--are moderately well drained (seasonal high water table 46 to 76 centimeters (18 to 30 inches), fine-loamy, and are on slightly lower landscapes
Augusta soils--are somewhat poorly drained (seasonal high water table 30 to 46 centimeters (12 to 18 inches), fine-loamy, and are on lower landscapes
Molena soils--are somewhat excessively drained, sandy, and on similar landscapes
Dogue soils--are moderately well drained (seasonal high water table 46 to 76 centimeters (18 to 30 inches), clayey, and are on sightly lower landscapes
Pamunkey soils--are well drained (seasonal high water table 122 to 183 centimeters (48 to 72 inches), fine-loamy, have a base saturation greater than 35 percent, and on similar landscapes
State soils--are well drained (seasonal high water table 122 to 183 centimeters (48 to 72 inches), fine-loamy family, and on similar landscapes
Wickham soils--are well drained (seasonal high water table is below 183 centimeters (72 inches), fine-loamy, and on similar landscapes
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Agricultural Drainage Class: Well drained
Index Surface Runoff: Medium
Saturated Hydraulic Conductivity: Moderately high
USE AND VEGETATION:
Major Uses: Mostly cropland with some woodland
Dominant Vegetation: Where cultivated--soybeans, pasture, and corn. Where wooded--loblolly pine, sweet gum, oak, hickory, and maple
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Auburn, Alabama
DISTRIBUTION AND EXTENT:
Distribution: South Carolina, and possibly Georgia and North Carolina
Extent: Small
SERIES PROPOSED: Chester County, South Carolina, 2005.
REMARKS: Thomson soils were previously mapped as Molena Variant (SIR SC0092)
Diagnostic horizons and other features recognized in this pedon are:
Ochric epipedon--the zone from 0 to 23 centimeters (0 to 9 inches) (Ap horizon).
Argillic horizon--the zone from 23 to 76 centimeters (9 to 30 inches) (Bt horizon) and between 150 to 203 centimeters (59 to 80 inches) (2Bt2 and 2Bt3 horizons).
REVISED=12/20/05, DTA. This revision changed the taxonomic classification from coarse-loamy, mixed, thermic Typic Hapludult based on lab data. 10/06
DTA-This revision changes the location to a more typical site, within the same map unit, and extends the description to 203 centimeters (80 inches). The January 2026 revision updated the format. No data was changed. Molena Variant in Chester County is now named Thomson.
ADDITIONAL DATA: Laboratory data from typical pedon and supporting pedons S04SC-023(1-3), Data may be obtained from Clemson University.
TABULAR SERIES DATA:
SOI-5 Soil Name Slope Airtemp FrFr/Seas Precip Elevation
SC0092 THOMSON 0-10 58-60 190-220 40-50 100-250
SOI-5 FloodL FloodH Watertable Kind Months Bedrock
SC0092 NONE >60 >60
SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC-
SC0092 0-9 SL FSL L 0-0 95-100 3-8
SC0092 9-30 FSL L SL 0-0 95-100 11-16
SC0092 30-59 LFS SL L 0-0 75-100 1-8
SC0092 59-80 SCL L 0-0 75-100 18-30
SOI-5 Depth -pH- O.M. Salin Permeab Shnk-Swll
SC0092 0-9 4.5-6.5 .5-2. 0-0 2.0-6.0 LOW
SC0092 9-30 4.5-6.5 0.-.5 0-0 2.0-6.0 LOW
SC0092 30-59 4.5-6.5 0.-.5 0-0 6.0-20 LOW
SC0092 59-80 4.5-6.5 0.-.5 0-0 0.6-2.0 LOW
________________________________________
National Cooperative Soil Survey
U.S.A.