LOCATION CHAZOS TX

Established Series
Rev. CLN-JAW-RM-HLH
04/2022

CHAZOS SERIES

The Chazos series consists of very deep, moderately well drained, slowly permeable soils that formed in loamy and clayey alluvium derived from sandstone and shale. These soils are on stream terraces on river valleys or dissected plains. The slope range is 0 to 8 percent. Mean annual precipitation is about 939.8 mm (37 in) and the mean annual air temperature is about 19.4 degrees C (67 degrees F).

TAXONOMIC CLASS: Fine, smectitic, thermic Udic Paleustalfs

TYPICAL PEDON: Chazos loamy fine sand--pasture. (Colors are for moist soil unless otherwise stated).

A--0 to 15 cm (0 to 6 in); brown (10YR 4/3) loamy fine sand, light yellowish brown (10YR 6/4) dry; weak fine granular structure; slightly hard, friable; common fine roots; common fine pores; few fine and medium rounded siliceous pebbles; slightly acid; clear smooth boundary.

E--15 to 38 cm (6 to 15 in); yellowish brown (10YR 5/4) loamy fine sand, very pale brown (10YR 7/4) dry; single grained; slightly hard, very friable; common fine roots; common fine pores; few fine and medium rounded siliceous pebbles; slightly acid; abrupt wavy boundary. (Combined thickness of the A and E horizons is 25 to 50 cm [10 to 20 in])

Bt1--38 to 56 cm (15 to 22 in); red (2.5YR 4/8) clay, red (2.5YR 5/8) dry; moderate medium prismatic structure parting to moderate medium angular blocky; very hard, very firm; few fine roots; few fine pores; few pressure faces; few thin clay films on surfaces of prisms; few iron-manganese concretions; few fine rounded siliceous pebbles; common fine and medium distinct brownish yellow (10YR 6/6) masses of iron accumulation; and pale brown (10YR 6/3) iron depletions; moderately acid; gradual wavy boundary.

Bt2--56 to 74 cm (22 to 29 in); dark yellowish brown (10YR 4/4) clay loam, yellowish brown (10YR 5/4) dry; moderate medium prismatic structure parting to coarse angular blocky; very hard, very firm; few fine roots; few fine pores; few pressure faces; few thin clay films on surfaces of prisms; few iron-manganese concretions; few fine rounded siliceous pebbles; many fine and medium prominent yellowish red (5YR 5/8) masses of iron accumulation, and common fine faint brown (10YR 5/3) iron depletions; moderately acid; diffuse wavy boundary.

Bt3--74 to 86 cm (29 to 34 in); dark grayish brown (2.5Y 4/2) clay loam; moderate medium prismatic structure parting to weak coarse angular blocky; very hard, very firm; few fine roots; few fine pores; few pressure faces; few thin clay films on surfaces of prisms; common fine iron-manganese concretions; common medium distinct dark yellowish brown (10YR 4/4), and few fine prominent red (2.5YR 4/6) masses of iron accumulation; common medium distinct light brownish gray (10YR 6/2) iron depletions; slightly acid; diffuse smooth boundary. (Combined thickness of the Bt horizon is 38 to 135 cm [15 to 53 in])

Btk--86 to 119 cm (34 to 47 in); light olive brown (2.5Y 5/3) sandy clay loam, moderate medium prismatic structure parting to weak coarse subangular blocky; very hard, firm; few fine roots; few fine pores; few thin clay films on surfaces of prisms; 3 percent fine concretions of calcium carbonate; common fine iron-manganese concretions; few siliceous pebbles; common medium and coarse distinct yellowish brown (10YR 5/4) masses of iron accumulation; slightly effervescent; moderately alkaline; gradual smooth boundary. (Thickness is 0 to 50 cm [0 to 20 in])

BCtk1--119 to 165 cm (47 to 65 in); light yellowish brown (2.5Y 6/3) sandy clay loam; moderate medium prismatic structure parting to weak coarse subangular blocky; very hard, firm; few fine roots; few fine pores; common patchy clay films on surfaces of peds; few fine concretions of calcium carbonate; few fine siliceous pebbles; few medium prominent brown (7.5YR 5/4) and few fine prominent red (2.5YR 4/6) masses of iron accumulation; slightly alkaline; gradual boundary. (Thicknes is 25 to 89 cm [10 to 35 in])

2BCt--165 to 203 cm (65 to 80 in); reddish brown (5YR 5/4) silty clay loam; weak medium subangular blocky structure; very hard, firm; few fine roots; few fine and medium pores; common patchy clay films on surfaces of peds; few fine iron-manganese stains and concretions; few fine distinct red (2.5YR 4/6) masses of iron accumulation; moderately alkaline.

TYPE LOCATION: Falls County, Texas; from the intersection of Texas Highway 7 and Texas Highway 6 bypass in Marlin; 1.3 miles south on Texas Highway 6; 200 ft west in rangeland.

USGS Marlin topographic quadrangle
Latitude: 31 degrees, 17 minutes, 16.459 seconds N
Longitude: 96 degrees, 52 minutes, 33.058 seconds W

Decimal Degrees
Std Latitude: 31.0287905
Std Longitude: -96.875849

RANGE IN CHARACTERISTICS:
Soil Moisture: An ustic soil moisture regime. The soil moisture control section is dry in some or all parts for more than 90 days but less than 150 cumulative days in normal years.
Soil depth: very deep 152 to more than 203 cm (60 to more than 80 in)
Depth to abrupt textural change: 25 to 51 cm (10 to 20 in)
Depth to albic materials: 10 to 33 cm (4 to 13 in)
Depth to albic horizon: 10 to 33 cm (4 to 13 in)
Depth to argillic horizon: 25 to 51 cm (10 to 20 in)
Depth to secondary calcium carbonate: 68 to 191 cm (27 to 75 in) where present
Depth to gypsum accumulations: 91 cm (36 in) where present
Depth to redox concentrations: 33 to 165 cm (13 to 65 in) where present
Depth to redox depletions: 30 to 43 cm (12 to 17 in) where present
Thickness of the ochric epipedon: 25 to 50 cm (10 to 20 in)

Particle-size control section (weighted average)
Clay content: 35 to 50 percent
Rock fragments: 0 to 14 percent

A horizon:
Hue: 7.5YR or 10YR
Value: 4 or 6
Chroma: 2 to 4
Texture: loamy sand or loamy fine sand
Rock fragments: amount-0 to 14 percent; size-2 to 75 mm, kind-quartzite
Reaction (pH): slightly acid (moderately acid to neutral)

E horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7
Chroma: 2 to 4
Texture: loamy sand or loamy fine sand
Rock fragments: amount- 0 to 14 percent; size- 2 to 75 mm, kind- quartzite
Reaction (pH): slightly acid (moderately acid to neutral)

Bt1 and Bt2 Horizon:
Hue: 2.5YR to 10YR
Value: 4 to 6
Chroma: 4 to 8
Texture: clay loam, sandy clay, or clay
Clay content: 35 to 50 percent
Clay films: location- on all faces of peds, contrast- faint to prominent
Redox concentrations: amount- 0 to 25 percent, size- fine to medium, contrast- faint to prominent, shade- red, brown, and yellow
Redox depletions: amount- 0 to 35 percent, size- medium, contrast- distinct to prominent, shade- gray
Iron-manganese concentrations: amount- 0 to 1 percent; size- fine to medium
Rock fragments: amount- 0 to 15 percent; size- 2 to 75 mm; kind-quartzite
Reaction (pH): moderately acid (strongly acid to slightly acid)

Lower Bt or Btg Horizon:
Hue: 10YR or 2.5Y
Value: 4 to 7
Chroma: 2 to 6
Texture: sandy clay loam, clay loam, sandy clay
Clay content: 27 to 40 percent
Clay films: location- on all faces of peds, contrast- faint to prominent
Redox concentrations: amount- 0 to 25 percent, size- fine to coarse, contrast- faint to prominent, shades- red, brown, yellow
Redox depletions: amount- 0 to 25 percent, size- medium, contrast- distinct to prominent, shades- gray
Iron-manganese concentrations: amount- 0 to 5 percent; size- medium
Rock fragments: amount- 0 to 15 percent; size- 2 to 75 mm; kind- quartzite
Reaction (pH): slightly acid (strongly acid to neutral)

Btk Horizon:
Hue: 7.5YR, 10YR or 2.5Y
Value: 5
Chroma: 3 to 6
Texture: sandy clay loam, clay loam, sandy clay
Clay content: 20 to 40 percent
Clay films: location- on all faces of peds
Redox concentrations: amount- 0 to 5 percent, size- medium to coarse, contrast- distinct
Iron-manganese concentrations: amount- 0 to 20 percent; size- fine
Rock fragments: amount- 0 to 15 percent; size- 2 to 75 mm; kind- quartzite
Identifiable secondary carbonate: amount- 0 to 3 percent, size- fine, kind- carbonate concretions
Reaction (pH): moderately alkaline (slightly alkaline to moderately alkaline)

BC, BCt, BCty, or BCtk Horizon (when present):
Hue: 5YR, 7.5YR, 10YR, or 2.5Y
Value: 4 to 7
Chroma: 2 to 6
Texture: clay loam, clay, sandy clay loam, silty clay loam
Clay content: 27 to 45 percent
Clay films: location- on all faces of peds (when present)
Redox concentrations: amount- 0 to 20 percent, size- fine to medium, contrast- distinct to prominent
Redox depletions: amount- 0 to 10 percent, size- fine to medium, contrast- distinct
Iron-manganese concentrations: amount- 0 to 1 percent; kind- iron-manganese masses
Rock fragments: amount- 0 to 15 percent; size- 2 to 75 mm; kind- quartzite
Identifiable secondary carbonate: amount- 0 to 1, size- fine, kind- carbonate concretions (when present)
Gypsum: amount- 0 to 1 percent (when present)
Reaction (pH): slightly alkaline (slightly acid to moderately alkaline)

2BCt or BC Horizon (when present):
Hue: 5YR, 7.5YR, 10YR, 2.5Y
Value: 4 to 6
Chroma: 2 to 5
Texture: sandy clay loam, silt loam, silty clay loam, fine sandy loam, sandy clay loam, and weakly consolidated sandstone (some layers are stratified)
Clay films: location- on all faces of peds (when present)
Redox concentrations: amount- 0 to 1 percent, size- fine, contrast- distinct
Iron-manganese concentrations: amount- 0 to 1 percent; size- fine; kind- concentrations and masses
Rock fragments: amount- 0 to 15 percent; size- 2 to 75 mm; kind- quartzite
Reaction (pH): moderately alkaline (slightly alkaline to moderately alkaline)

COMPETING SERIES: These are the Arol, Gredge, Payne, and Singleton series. Similar soils include the Axtell, Cadell, Chaney, Fett, Straber, Tabor, and Zack series.
Arol, and Singleton soils: have sola between 51 and 102 cm (20 and 40 in).
Gredge soils: have A and E horizons that average less than 25 cm (10 in) thick.
Payne soils: do not have an abrupt textural change between the epipedon and argillic horizon.
Axtell, Tabor, and Zack soils: have vertic properties.
Cadell soils: have sola 102 to 152 cm (40 to 60 in) thick.
Chaney and Straber soils: have mixed mineralogy.
Fett soils: have a clayey-skeletal control section.

GEOGRAPHIC SETTING:
Parent material: loamy and clayey alluvium derived from sandstone and shale
Landscape: dissected plains, river valleys
Landform: convex linear treads on stream terraces
Slope: 0 to 8 percent
Mean annual precipitation: 889 to 1143 mm (35 to 45 in)
Mean annual air temperature: 18.6 to 20.9 degrees C (65.5 to 69.6 degrees F)
Frost Free period: 240 to 288 days
Elevation: 37.5 to 177.4 m (123 to 580 ft)
Thornthwaite P-E Index: 52 to 66.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Axtell and Tabor series, and the Padina, Silawa, Silstid, Robco, and Tremona series.
Padina soils: are higher in the landscape, and have sandy surface layers more than 40 inches thick.
Silstid soils: are slightly higher in the landscape, have fine-loamy control sections and arenic epipedons.
Silawa soils: are on about the same or slightly lower positions in the landscape, and have fine-loamy control sections.
Tremona soils: are higher than Chazos but in lower positions than Padina and Silstid in the landscape. They are found on footslopes generally, are hyperthermic, have an aquic moisture regime, and have an arenic epipedon.
Robco soils: are found in similar positions to Tremona, have a fine-loamy control section, have an aquic moisture regime, and have an arenic epipedon.
Axtell soils: are on about the same or slightly lower positions in the landscape and have vertic properties.
Tabor soils: are on similar positions to Axtell, have vertic properties, and an oxyaquic moisture regime.

DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is slow. Runoff is medium on slopes less than 1 percent, high on 1 to 5 percent slopes, and very high on 5 to 8 percent slopes.

USE AND VEGETATION: Most areas are in pasture, but a few areas are farmed to peanuts, sorghums, and small grain. Native vegetation includes an overstory of post oak and blackjack oak, with an understory of little bluestem, purpletop, beaked panicum, brownseed paspalum, Indiangrass, and low panicums.

DISTRIBUTION AND EXTENT: South-central Texas; Land Resource Region J - Southwestern Prairies Cotton and Forage Region; MLRA 87A - Texas Claypan Areas, Southern Part, along terraces of rivers and large streams or remnants of terraces associated with uplands. The series is of large extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Falls County, Texas; 1976.

REMARKS: Classification changed (11/91) from mixed mineralogy to montmorillonitic mineralogy based on TAMU data from the series type location in Falls County and the typifying pedons in Milam, McLennan and Brazos Counties, Texas.
Classification changed (4/93) from Aquic subgroup to Udic subgroup based on changes in aquic soil definitions and moisture data from similar soils.

Diagnostic horizons and features recognized in this pedon are:
Particle size control section: 38 to 88 cm (15 to 35 in) (Bt1, Bt2, Bt3, and upper part of Btk horizons)

Ochric epipedon: 0 to 38 cm (0 to 15 in) (A and E horizons)
Argillic horizon: 38 to 203 cm (15 to 80 in) (Bt, Btk, BCt, and 2BCt horizons)
Albic horizon: 15 to 38 cm (6 to 15 in) E horizon
Redoximorphic features: 38 to 203 cm (15 to 80 in)
Abrupt textural change: at the upper boundary of the Bt1 horizon
Identifiable secondary carbonate: 86 to 165 cm (34 to 65 in) (Btk and BCtk horizons)
Lithologic discontinuity: At the upper boundary of the 2BCt horizon

ADDITIONAL DATA: None

Soil Interpretation Record: TX0552

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014.

National Cooperative Soil Survey
U.S.A.