LOCATION HALLSBLUFF TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Typic Hapluderts
TYPICAL PEDON: Hallsbluff clay loam--pastureland. (Pedon described midway between the microknoll and the microdepression. Colors are for moist soil unless otherwise stated)
Ap--0 to 6 inches; very dark grayish brown (10YR 3/2) clay loam; moderate medium angular blocky structure; very hard, very firm; many fine and few medium roots; few medium vesicular and tubular pores; many fine and medium worm casts; few fine concretions of calcium carbonate; few siliceous pebbles; slightly effervescent; moderately alkaline; clear smooth boundary.
A--6 to 17 inches; very dark grayish brown (10YR 3/2) silty clay; moderate medium angular blocky structure; very hard, very firm; common fine roots; few medium vesicular and tubular pores; few pressure faces; many fine and medium worm casts; few fine threads of calcium carbonate; few siliceous pebbles; very slightly effervescent; moderately alkaline; gradual wavy boundary. (combined A horizons 12 to 22 inches thick)
Bss--17 to 29 inches; very dark grayish brown (10YR 3/2) silty clay; moderate medium angular blocky structure; very hard, very firm; few fine roots; many fine and medium vesicular and tubular pores; common medium distinct light olive brown (2.5Y 5/4) redox concentrations or masses with sharp boundaries; few fine and medium worm casts; common pressure faces and slickensides; few fine concretions of calcium carbonate; few siliceous pebbles; very slightly effervescent; moderately alkaline; clear wavy boundary. (0 to 20 inches thick)
Bkss1--29 to 40 inches; olive (5Y 5/3) clay; moderate coarse angular blocky structure; very hard, very firm; common fine roots; many fine and medium vesicular and tubular pores; common fine distinct dark grayish brown (10YR 4/2), and very dark gray (10YR 3/1) redox depletions or masses with sharp boundaries; many pressure faces and slickensides with angles 40 to 50 degrees from horizontal; few fine and medium masses of iron-manganese; many fine and medium concretions of calcium carbonate; few siliceous pebbles; slightly effervescent; moderately alkaline; clear irregular boundary.
Bkss2--40 to 52 inches; light olive brown (2.5Y 5/4) clay; moderate coarse angular blocky structure parting to weak medium subangular blocky; very hard, very firm; common fine roots; many fine vesicular and tubular pores; many fine distinct dark grayish brown (10YR 4/2) redox depletions or masses with sharp boundaries; common pressure faces and many grooved slickensides; common medium concretions of calcium carbonate; few medium masses of iron-manganese; slightly effervescent; moderately alkaline; gradual wavy boundary. (combined Bkss subhorizons 18 to 50 inches thick)
BCss--52 to 80 inches; yellowish brown (10YR 5/8) clay; weak medium angular blocky structure; very hard, very firm; common fine roots; few fine and medium vesicular and tubular pores; common fine and medium prominent light brownish gray (10YR 6/2) redox depletions with sharp boundaries; common pressure faces and grooved slickensides; few medium and coarse concretions of calcium carbonate; few medium masses of iron-manganese; slightly effervescent; moderately alkaline.
TYPE LOCATION: Houston County, Texas; From intersection of Loop 304 and Texas Highway 7 on west side of Crockett; 4.5 miles southwest on Texas Highway 7 to intersection of Farm Road 132; 4.5 miles southwest on Farm Road 132 to end of pavement; 2.6 miles west on county road; 0.4 of mile south of county road in pasture to site. (Longitude: 95 degrees, 42 minutes, 42 seconds west; Latitude 31 degrees, 13 minutes, 38 seconds north)
RANGE IN CHARACTERISTICS: Solum thickness is more than 80 inches. The control section has a weighted average clay content of 45 to 60 percent. Unless cultivated there is gilgai micro-relief with microknolls 6 to 10 inches higher than microdepressions. Typically, in areas with slopes of 3 percent or more, the knolls and depressions occur as low ridges and valleys that are parallel with the slope. They form a tiger stripe pattern on aerial phopography. The soil cracks when dry. Cracks range from 1/2 an inch to about 2 inches wide and extend to a depth of more than 12 inches. The cracks are open for 60 to 90 cumulative days during most years. Slickensides and/or wedge shaped peds begin at a depth of 12 to 22 inches. The amplitude of waviness of mollic to non-mollic colors ranges from a extreme depth of 6 inches on microknolls to 40 inches in microdepressions. Some microknolls have spots (chimneys) that do not have mollic colored surfaces. The redox masses in this soil are considered to be mainly relic.
The A horizon has hue of 10YR to 5Y with value of 3 and chroma of 1 or 2. If the chroma is less than 1.5 the horizon is less than 12 inches thick in more than 50 percent of the pedon. Some pedons have a few masses in shades of brown in the lower part. The texture is clay loam, silty clay, or clay. The matrix is dominantly effervesent, but ranges to noneffervescent and slightly alkaline in the upper part of some microdepressions.
The Bss horizon has hue of 10YR to 5Y, value of 3 or 4, chroma of 2. Redox masses in shades of brown, yellow or olive range from none to common. The texture is silty clay or clay.
The Bkss horizon has hue of 10YR to 5Y, value of 3 to 6, and chroma of 2 to 8. Redox masses in shades of brown, yellow or olive range from few to common. Calcium carbonate threads, concretions, and masses range from 3 to 15 percent.
The BCss horizon has hue of 10YR to 5Y, value of 4 to 6, and chroma of 4 to 8. Redox masses in shades of brown, yellow, or gray range from few to common. Calcium carbonate concretions and masses ranges from about 1 to 10 percent. Gypsum crystals are in the lower part of some pedons.
COMPETING SERIES: These include the Eastham and Tinn series in the same family and the similar Heiden and Garner series. Eastham, Garner, and Tinn soils have an A horizon with chroma of 1 to a depth of more than 12 inches. In addition the Tinn soils are on flood plains. Heiden soils are in the ustic moisture regime and have a solum 40 to 65 inches thick.
GEOGRAPHIC SETTING: Hallsbluff soils are on erosional convex surfaces mainly on low scarpes separating the first and second terrace levels of the Trinity River system draining the Blackland Prairie. The soil formed in clayey alluvial sediments. Slopes range from 2 to 5 percent. The average annual temperature ranges from 65 to 68 degrees F. The average annual rainfall ranges from 40 to 46 inches and the Thornwaite P-E index ranges from 66 to 70. The elevation ranges from 175 to 225 feet above sea level. Frost free days range from 230 to 260.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Annona, Derly, Etoile, Freestone, Garner, and Eastham soils. Annona, Derly, Etoile, and Freestone soils have argillic horizons. Annona and Etoile soils are above on slightly higher positions. Derly and Freestone soils are on similar or slightly lower terrace positions. The competing Eastham and Garner series have slopes less than 3 percent and are on lower positions.
DRAINAGE AND PERMEABILITY: It is well drained, with very slow permeability, and high runoff. Infiltration is rapid when the soil is dry and cracked, but very slow when it is wet.
USE AND VEGETATION: Used mainly for pasture and hayland. Most areas have been cultivated in the past but now are used for pasture. Bermudagrass and kleingrass are adapted and are grown on this soil. Some areas are cultivated to grain sorghum or small grain. Native grasses include bluestems, Indiangrass, buffalograss, tridens, and threeawn. There are a few scattered mesquite in some areas.
DISTRIBUTION AND EXTENT: East Central Texas in MLRA 133B, mainly on the terrace of the Trinity River. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES PROPOSED: Houston County, Texas; 1991. The name Hallsbluff is from a nearby small community.
REMARKS: Formerly included in the Heiden or Ferris series. This soil would be classified in an aquic subgroup if the mottles at a depth of 17 inches reflect the present moisture system. However, these mottles are considered relic because they have sharp boundaries between colors and the drainage, slope, position, use, and managmennt indicate wetness is not a problem. Classification changed from Typic Chromuderts to Typic Hapluderts in February, 1994 based on Issue 16 of Soil Taxonomy.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 17 inches (the Ap, A and Bss horizons).
Cambic horizon - 17 to 80 inches (Bss, Bkss, and BCss horizons).
Vertisol feature - cracks when dry; and intersecting slickensides from 17 to 80 inches.
ADDITIONAL DATA: TAMU data S90-TX-225-3.
SOIL INTERPRETATION RECORD NUMBER: TX1231