LOCATION SPINDLETOP TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, hyperthermic Oxyaquic Argiudolls
TYPICAL PEDON: Spindletop silt loam--pasture.
(Colors are for moist soil unless otherwise stated.)
A--0 to 12 inches; very dark gray (10YR 3/1) silt loam; weak fine granular structure; slightly hard, friable; many fine and medium roots; common fine pores; strongly acid; clear smooth boundary. (10 to 14 inches thick)
E1--12 to 16 inches; dark grayish brown (10YR 4/2) silt loam; weak fine subangular blocky structure; slightly hard, friable; few fine roots; few fine pores; strongly acid; clear smooth boundary.
E2--16 to 25 inches; grayish brown (10YR 5/2) silt loam; weak medium subangular blocky structure; slightly hard, friable; few fine roots; common fine pores; common medium distinct yellowish brown (10YR 5/6) iron accumulations; slightly acid; gradual wavy boundary. (combined thickness of the E horizons is 10 to 25 inches)
Bt/E--25 to 29 inches; light brownish gray (10YR 6/2) silty clay loam (Bt); 15 percent light brownish gray (10YR 6/2) albic material (E) on surface of prisms; strong coarse prismatic structure parting to moderate medium angular blocky; hard, firm; few fine roots; common fine medium pores; common medium prominant distinct yellowish brown (10YR 5/6) iron accumulations; neutral; gradual wavy boundary. (3 to 10 inches thick)
Btg1--29 to 39 inches; light brownish gray (10YR 6/2) clay; moderate coarse prismatic structure parting to moderate subangular blocky; very hard, very firm; few fine roots; few fine and medium pores; common medium prominant yellowish brown (10YR 5/6) iron accumulations; common distinct dark gray clay films on surface of peds; few fine iron-manganese concretions; slightly alkaline; gradual wavy boundary.
Btg2--39 to 56 inches; light gray (10YR 6/1) clay; moderate coarse prismatic structure parting to moderate subangular blocky; very hard, very firm; few fine roots; few fine and medium pores; common medium prominant yellowish brown (10YR 5/6) and yellowish red (5YR 5/8) iron accumulations; common distinct gray (10YR 5/1) clay films on surface of peds; few medium calcium carbonate concretions; slightly alkaline; gradual wavy boundary.
Btg3--56 to 80 inches; light gray (10YR 7/1) clay; moderate coarse prismatic structure parting to moderate subangular blocky; very hard, very firm; common medium prominant strong brown (7.5YR 5/8) iron accumulations; few very coarse calcium carbonate concretions; slightly alkaline. (combined thickness of Btg subhorizons is 40 to more than 60 inches).
TYPE LOCATION: Jefferson County, Texas; From the intersection of Texas Highway 73 and 124 southwest of Hampshire; 7.0 miles east on Texas Highway 73; 3.5 miles south on Big Hill Road; 1.2 miles east on Needmore Road; 0.6 miles south on field road; 100 feet west in pasture on mound. (Latitude 29N, 45, 56; Longitude 94W, 12, 29)
RANGE IN CHARACTERISTICS: Solum thickness is more than 80 inches. Combined thickness of the silt loam or loam A and E horizons ranges from 15 to 30 inches. Clay content of the particle-size control section ranges from 35 to 50 percent with silt content exceeding 30 percent.
The A horizon has colors with hue of 10YR, value of 3, and chroma of 1 to 3. Iron accumulations in shades of brown range from none to common. Reaction ranges from strongly acid to neutral.
The E horizons has colors with hue of 10YR, value of 4 to 6, and chroma of 2 or 3. Iron accumulations in shades of brown, red, or yellow range from few to common. Reaction ranges from strongly acid to neutral.
The Bt/E horizon has colors with hue of 10YR, value of 4 to 6, and chroma of 1 or 2. Color of the albic material has hue 10YR, value 5 to 7, and chroma 1 or 2. Iron accumulations in shades of red, brown, and yellow range from common to many. Texture is loam, silt loam, or silty clay loam. Reaction ranges from slightly acid to slightly alkaline.
The upper part of the Btg horizon has colors with hue of 10YR, value of 4 to 6, and chroma of 1 or 2. Iron accumulations in shades of red, brown, and yellow range from common to many. Texture is silty clay or clay. Reaction ranges from neutral to moderately alkaline.
The lower part of the Btg horizon has color with hue of 10YR or 2.5Y, value of 5 to 7, and chroma of 1 or 2. Iron accumulations in shades of brown, red, or yellow range from few to many. Texture is silty clay or clay. Calcium carbonate concretions range from none to about 5 percent. Reaction ranges from neutral to moderately alkaline.
COMPETING SERIES: There are no competing series. Similar soils are the Anahuac, Aldine, Aris, and Crowley series. Anahuac soils have a mollic colored surface layer with less than 50 percent base saturation and are more acid in the lower part of the Btg. Aldine, Aris, and Crowley soils have a ochric epipedon. Also, Aris and Crowley soils have aquic conditions within 20 inches of the surface in most years.
GEOGRAPHIC SETTING: Spindletop soils are on nearly level uplands. Slopes range from 0 to 1 percent. These soils are on the Coast Prairie east of the Trinity River. The soils formed in loamy and clayey sediments of the Beaumont Formation of Pleistocene age. A typical landscape position is circular mounds 75 to 200 feet in diameter and 1 to 3 feet above the intermound landscape. Mean annual precipitation ranges from 50 to 60 inches. Mean annual temperature ranges from 70 to 72 degrees F. Frost free days range from 250 to 270. Elevation ranges from 5 to 35 feet. Thornthwaite P-E index ranges from 68 to 80.
GEOGRAPHICALLY ASSOCIATED SOILS: These include Anahuac, Aldine and Aris of the competing series and Labelle, Leton, Levac, Meaton, and Morey series. Anahuac and Aldine soils are on nearby stream meander ridges slightly higher in the landscape. Aris soils are lower in the landscape and are poorly drained. Labelle and Levac soils are somewhat poorly drained and are on slightly lower landscape positions. Meaton and Morey soils are on intermound positions in a complex with Spindletop soils. Also, Labelle, Levac, Meaton, and Morey soils have surface layers less than 15 inches thick. Leton soils are on poorly drained stream meander channels lower in the landscape.
DRAINAGE AND PERMEABILITY: Spindletop soils are moderately well drained. Permeability is very slow. Runoff is low. These soils are saturated from 18 to 30 inches below the soil surface for a period of 30 days or more in most years. In some years these soils have aquic conditions.
USE AND VEGETATION: Used primarily for pasture and hayland. Pastures are bahiagrass or bermudagrass. A few areas are used for horticultural crops. Native vegetation is tall prairie grasses, mainly species of andropogons, paspalums, switchgrass, and indiangrass.
DISTRIBUTION AND EXTENT: The Gulf Coast Prairie (MLRA 150A) of southeast Texas east of the Trinity River and possibly Louisiana. The series is of minor extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Jefferson County, Texas; 1996. The name comes from a local oil field.
REMARKS: The Spindletop series was previously included with the Anahuac series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 12 inches (A horizon).
Albic horizon - 12 to 25 inches (E1 & E2 horizon).
Glossic horizon - 25 to 29 inches (Bt/E horizon; this horizon is not diagnostic to classification).
Argillic horizon - 29 to 80 inches (Btg horizons).
Oxyaquic feature - Are saturated in the E2 horizon for 30 days or more in most years. In some years these soils have aquic conditions.
SOIL INTERPRETATIONS RECORD NUMBER: TX1211