LOCATION PITTSBORO NC
Established Series
RDH,STE,DTA
09/2025
PITTSBORO SERIES
MLRA(s): 136 (thermic part)
Soil Survey Regional Office (SSRO) Responsible: Southeast
Depth Class: Moderately deep
Agricultural Drainage Class: Moderately well drained
Index Surface Runoff: Medium
Saturated Hydraulic Conductivity Class: Low
Shrink-Swell Potential: High
Landscape: Piedmont uplands
Landform: Interstream divides, ridges, and side slopes
Parent Material: Residuum weathered from basalt, greenstone, gabbro, diabase, diorite, and other dark-colored mafic rocks
Slope: 2 to 15 percent
Mean Annual Air Temperature: 15 degrees C (60 degrees F)
Mean Annual Precipitation: 1194 millimeters (47 inches)
TAXONOMIC CLASS: Fine, mixed, active, thermic Oxyaquic Hapludalfs
TYPICAL PEDON: Pittsboro gravelly sandy loam, on a 3 percent slope in a mixed hardwood forest. (Colors are for moist soil.)
A1--0 to 13 centimeters (0 to 5 inches); brown (10YR 4/3) gravelly sandy loam; moderate fine granular structure; friable; slightly sticky, non-plastic; many fine roots; slightly acid; abrupt smooth boundary. (0 to 20 centimeters (0 to 8 inches) thick)
A2--13 to 23 centimeters (5 to 9 inches); dark yellowish brown (10YR 4/4) gravelly loam; weak coarse granular structure; friable; slightly sticky, non-plastic; common fine roots; slightly acid; clear smooth boundary. (0 to 20 centimeters (0 to 8 inches) thick)
BE--23 to 41 centimeters (9 to 16 inches); yellowish brown (10YR 5/6) loam; moderate medium subangular blocky structure; friable; moderately sticky, moderately plastic; common fine roots; few distinct clay films on faces of peds; slightly acid; gradual wavy boundary. (0 to 20 centimeters (0 to 8 inches) thick)
Btss1--41 to 61 centimeters (16 to 24 inches); yellowish brown (10YR 5/6) clay; moderate medium angular blocky structure; firm; very sticky, very plastic; common fine roots; common distinct clay films on faces of peds; common distinct nonintersecting slickensides; slightly acid; clear wavy boundary.
Btss2--61 to 84 centimeters (24 to 33 inches); yellowish brown (10YR 5/6) clay; moderate medium angular blocky structure; very firm; very sticky, very plastic; common fine roots; common fine prominent black (10YR 2/1) soft masses of manganese accumulation; common distinct clay films on faces of peds; common distinct nonintersecting slickensides; neutral; clear wavy boundary. (Combined thickness of the Btss horizons is 0 to 51 centimeters (0 to 20 inches)
BCt--84 to 91 centimeters (33 to 36 inches); yellowish brown (10YR 5/6) clay loam; weak coarse angular blocky structure; very firm; very sticky, very plastic; few fine roots; common medium prominent light gray (10YR 7/1) iron depletions in the matrix and common medium distinct grayish brown (10YR 5/2) iron depletions lining old root channels; neutral; wavy boundary. (0 to 25 centimeters (0 to 10 inches) thick)
C--91 to 96 centimeters (36 to 38 inches); yellowish brown (10YR 5/6) clay loam; massive; firm; very sticky, moderately plastic; few fine roots; neutral; abrupt wavy boundary. (0 to 25 centimeters (0 to 10 inches) thick)
Cr--96 to 109 centimeters (38 to 43 inches); weathered moderately fractured meta-basalt.
R--109 centimeters (43 inches); unweathered slightly fractured meta-basalt
TYPE LOCATION: Chatham County, North Caronia; about 6.9 miles north of Pittsboro on Secondary Road 1516; 450 feet left on gravel road; about 20 feet north of road; in a small patch of red cedar trees remaining in a clear cut area; USGS Bynum, North Carolina topographic quadrangle.
Latitude--35.808889
Longitude-- -79.0125
Datum--WGS84
RANGE IN CHARACTERISTICS:
Solum thickness: 51 to 102 centimeters (20 to 40 inches)
Depth to soft bedrock: 51 to 102 centimeters (20 to 40 inches) to weathered bedrock (paralithic contact--Cr)
Depth to hard bedrock: 102 to more than 152 centimeters (40 to more than 60 inches) to unweathered bedrock (lithic contact--R)
Depth to Seasonal High Water Table: 30 to 61 centimeters (12 to 24 inches)
Rock fragments on the surface: None to 15 percent; mostly cobbles, stones, or boulders
Rock Fragment Content: 0 to 60 percent, by volume, in the A, Ap, E, EB, and BE horizons and less than 35 percent, by volume, throughout the rest of the profile; mostly iron and manganese concretions, quartz pebbles, or dark colored mafic rocks.
Mica Content: 0 to 20 percent, by volume
Soil Reaction: Very strongly acid to slightly alkaline in the A, Ap, E, EB, and BE horizons, unless limed and strongly acid to moderately alkaline in the Bt, Btss, BC, and C horizons.
Note: While an argillic horizon is required, some pedons may lack either a Bt or Btss horizon. It is not required to have both.
RANGE OF INDIVIDUAL HORIZONS:
A or Ap horizon:
Color--hue of 7.5YR to 2.5Y, value of 3 to 6, chroma of 2 to 6
Texture (fine-earth fraction)--loam, fine sandy loam, sandy loam, or silt loam; where eroded, sandy clay loam or clay loam
E horizon (if it occurs):
Color--hue of 7.5YR to 2.5Y, value of 5 to 7, chroma of 3 to 6
Texture (fine-earth fraction)--loam, sandy loam, fine sandy loam, or silt loam
EB or BE horizon:
Color--hue of 7.5YR to 2.5Y, value of 4 to 7, chroma of 3 to 6
Texture (fine-earth fraction)--loam, silt loam, sandy loam, sandy clay loam, clay loam, or silty clay loam
Bt horizon (if it occurs):
Color--hue of 7.5YR to 2.5Y, value of 4 to 6, chroma of 4 to 8
Texture (fine-earth fraction)--clay, clay loam, silty clay, or sandy clay
Mottles (if they occur)--shades of yellow or brown
Redoximorphic features (if they occur)--iron or clay depletions in shades of gray below the upper 25 centimeters (10 inches) of the argillic horizon; iron accumulations in shades of red, brown, or yellow; iron-manganese accumulations in shades of black or gray
Btss horizon:
Color--hue of 7.5YR to 2.5Y, value of 4 to 6, chroma of 4 to 8
Texture (fine-earth fraction)--clay, silty clay, or sandy clay
Mottles (if they occur)--shades of yellow or brown
Redoximorphic features (if they occur)--iron or clay depletions in shades of gray below the upper 10 inches of the argillic horizon; iron accumulations in shades of red, brown, or yellow; iron-manganese accumulations in shades of black or gray
BCt horizon:
Color--matrix has hue of 7.5YR to 2.5Y, value of 4 to 7, chroma of 4 to 8, or is multicolored in shades of brown, yellow, black, or white
Texture (fine-earth fraction)--sandy clay, sandy clay loam, clay loam, silty clay loam, sandy loam, or loam
Redoximorphic features (if they occur)--iron or clay depletions in shades of gray or brown; iron accumulations in shades of red, brown, or yellow; iron-manganese accumulations in shades of black or gray
C or CB horizon:
Color--multicolored in shades of brown, yellow, black, gray, or white
Texture (fine-earth fraction)--variable; commonly clay loam, sandy loam, loam, or silt loam saprolite
Cr layer:
Type of bedrock--weathered, moderately fractured to highly fractured mafic rock
R layer:
Type of bedrock--unweathered, slightly fractured to moderately fractured mafic rock
COMPETING SERIES:
There are no known series in this family. Similar soils in related families are:
Brewback soils--have iron depletions in the upper Bt
Brickhaven soils--are semiactive, have a paralithic contact within a depth of 102 to 152 centimeters (40 to 60 inches), a moderate shrink-swell potential, and form in residuum weathered from Triassic age rocks
Carbonton soils--are semiactive, have a moderate shrink-swell potential, and form in residuum weathered from Triassic age rocks
Crawfordville soils--have an abrupt textural change between the A and Bt horizon
Virgilina soils--have a lithic contact within a depth of 51 to 102 centimeters (20 to 40 inches)
GEOGRAPHIC SETTING:
Landscape: Piedmont uplands
Landform: Ridges and hill slopes
Landform: Interstream divides, ridges, and side slopes
Parent Material: Residuum derived from basalt, greenstone, gabbro, diabase, diorite, and other dark-colored mafic rocks
Mean Annual Air Temperature: 16 degrees C (60 degrees F)
Mean Annual Precipitation: 1194 millimeters (47 inches)
Frost Free Period: 180 to 260 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Cid soils--have a moderate shrink-swell potential and are on similar landforms
Badin soils--are well drained, have a moderate shrink-swell potential, and are on similar landforms
Enon soils--are well drained, have no paralithic contact within a depth of 152 centimeters (60 inches), and are on similar landforms
Georgeville soils--are well drained, have a red Bt horizon, no paralithic contact within a depth of 152 centimeters (60 inches), a low shrink-swell potential, and are on similar landforms
Herndon soils--are well drained, have no paralithic contact within a depth of 152 centimeters (60 inches), a low shrink-swell potential, and are on similar landforms
Iredell soils--have a paralithic contact within a depth of 102 to 152 centimeters (40 to 60 inches), a very high shrink-swell potential, and are on similar landforms
Nanford soils--are well drained, have a paralithic contact within a depth of 102 to 152 centimeters (40 to 60 inches), a low shrink-swell potential, and are on similar landforms
Tarrus soils--are well drained, have a red Bt horizon, a paralithic contact within a depth of 102 to 152 centimeters (40 to 60 inches), a low shrink-swell potential, and are on similar landforms
Sedgefield soils--have no paralithic contact within a depth of 152 centimeters (60 inches) and are on similar landforms
Winnsboro soils--are well drained, have a paralithic contact at a depth of 102 to 152 centimeters (40 to 60 inches), and are on similar landforms
Wynott soils--are well drained and are on similar landforms
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Agricultural drainage class: Moderately well drained
Index Surface Runoff: Moderate
Saturated Hydraulic Conductivity Class: Low
USE AND VEGETATION:
Major Uses: Woodland, pasture, hayland, and cropland
Dominant Vegetation: Where wooded--Southern red oak, white oak, hickory, loblolly pine, shortleaf pine, post oak, blackjack oak, sweetgum, Eastern red cedar, winged elm, flowering dogwood, eastern redbud, red maple, hawthorn, and sassafras. Where cultivated--corn, soybeans, and small grain
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Auburn, Alabama
DISTRIBUTION AND EXTENT:
Distribution: North Carolina and possibly South Carolina, Georgia, and Virginia
Extent: Small
SERIES ESTABLISHED: Chatham County, North Carolina; 2005
REMARKS:
This series was formerly included with Zion, Orange, and Wynott soils. Zion soils are mesic, well drained and have a lithic contact at a depth of 51 to 102 centimeters (20 to 40 inches). Orange soils are mesic, have redoximorphic features in the upper 15 centimeters (10 inches) of the argillic horizon and have a paralithic contact at a depth of 102 to 152 centimeters (40 to 60 inches). Wynott soils are well drained.
The September 2025 revision corrected terminology. No data was changed.
Diagnostic horizons and soil characteristics recognized in this pedon:
Ochric epipedon--the zone from the surface of the soil to a depth of 23 centimeters (9 inches) (A1 and A2 horizons)
Argillic horizon--the zone between depths of 41 to 91 centimeters (16 to 36 inches) (Btss, and BCt horizons)
Paralithic contact--the occurrence of weathered bedrock at a depth of 97 centimeters (38 inches) (upper boundary of the Cr horizon)
Lithic contact--the occurance of unweathered bedrock at a depth of 109 centimeters (43 inches) (upper boundary of the R horizon)
ADDITIONAL DATA: Characterization data will be available from the Soil Survey Laboratory, Lincoln, Nebraska; pedon number S98NC-037-001
Typical Data Map Unit:
TABULAR SERIES DATA:
SOI-5 Soil Name Slope Airtemp FrFr/Seas Precip Elevation
NC PITTSBORO 2-15 57-65 170-200 41-53 200-850
NC PITTSBORO 2-15 57-65 170-200 41-53 200-850
SOI-5 FloodL FloodH Watertble Kind Months Bedrock Hardness
NC NONE 1.0-2.0 PERCH NOV-APR 20-40 SOFT
NC NONE 1.0-2.0 PERCH NOV-APR 20-40 SOFT
SOI-5 Depth Texture 3-Inch No-10 Clay% -CEC-
NC 0-9 GR-L GR-SL GR-FSL 0-5 55-90 5-20 5-15
NC 0-9 ST-L ST-SL ST-FSL 10-25 55-90 5-20 5-15
NC 9-16 CL SICL L 0-10 85-100 20-35 20-40
NC 16-33 C CL SIC 0-10 85-100 35-65 20-40
NC 33-38 CL SICL L 0-10 85-100 18-28 20-40
NC 38-43 WB - - - -
NC 43- UWB - - - -
NC 0-9 SL L FSL 0-5 85-100 5-20 5-15
NC 0-9 L SIL 0-5 90-100 10-27 5-15
NC 0-9 CL SCL 0-5 85-100 20-35 5-15
NC 9-16 CL SICL L 0-5 85-100 35-65 20-40
NC 16-33 SC SCL CL 0-5 85-100 20-45 10-25
NC 33-38 CL SICL L 0-5 85-100 18-28 20-40
NC 38-43 WB - - - -
NC 43- UWB - - - -
SOI-5 Depth -pH- -O.M.- Salin Permeab Shnk-Swll
NC 0-9 4.5-7.8 0.5-2.0 0-0 2.0-6.0 LOW
NC 0-9 4.5-7.8 0.5-2.0 0-0 2.0-6.0 LOW
NC 9-16 4.5-7.8 0-0.5 0-0 0.20-0.6 MODERATE
NC 16-33 4.5-7.8 0-0.2 0-0 0.06-0.6 HIGH
NC 33-38 5.0-8.2 0-0.2 0-0 0.20-0.6 MODERATE
NC 38-43 - - - - -
NC 43- - - - - -
NC 0-9 4.5-7.8 0.5-2.0 0-0 2.0-6.0 LOW
NC 0-9 4.5-7.8 0.5-2.0 0-0 2.0-6.0 LOW
NC 9-16 4.5-7.8 0-0.5 0-0 0.20-0.6 MODERATE
NC 16-33 4.5-7.8 0-0.2 0-0 0.06-0.6 HIGH
NC 33-38 5.0-8.2 0-0.2 0-0 0.20-0.6 MODERATE
NC 38-43 - - - - -
NC 43- - - - - -
________________________________________
National Cooperative Soil Survey
U.S.A.