LOCATION PAVELEK TX

Established Series
Rev. MLG-CLN-GWH
11/2010

PAVELEK SERIES

The Pavelek series are soils that are shallow to a petrocalcic horizon. These well drained, slowly permeable soils formed in clayey sediments over noncalcareous weakly cemented siltstone bedrock interbedded with layers of soft calcium carbonate of the Catahoula Formation. These soils are on nearly level to gently sloping, plane to slightly convex surfaces on ridges of inland, dissected coastal plains. Slopes range from 0 to 5 percent. Mean annual temperature is about 22 degrees C (73 degrees F) and mean annual precipitation is about 610 mm (24 in).

TAXONOMIC CLASS: Clayey, smectitic, hyperthermic, shallow Petrocalcic Calciustolls

TYPICAL PEDON: Pavelek clay--rangeland. (Colors are for dry soil unless otherwise stated)

A--0 to 18 cm (0 to 7 in); very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; strong fine angular blocky structure; very hard, very firm, very sticky, very plastic; many very fine and few fine and coarse roots; few very fine and fine tubular pores; 2 percent weakly cemented fragments of calcium carbonate 0.5 cm (1/4 in) across; slightly effervescent; moderately alkaline; clear wavy boundary. (Thickness is 8 to 46 cm [3 to 18 in].)

Bk--18 to 36 cm (7 to 14 in); very dark gray (10YR 3/1) gravelly clay, very dark gray (10YR 3/1) moist; moderate fine and very fine angular blocky structure; very hard, very firm, very sticky, very plastic; many very fine roots; few very fine and fine tubular pores; 5 percent concretions and masses of calcium carbonate less than 0.5 cm (1/4 in)in size, 15 percent platelike fragments of weakly cemented calcium carbonate 2.5 to 7.5 cm (1 to 3 in) across and 0.3 to 1.2 cm (1/8 to 1/2 in) thick; strongly effervescent; moderately alkaline; abrupt wavy boundary. (Thickness is 5 to 23 cm [2 to 9 in].)

Bkkm--36 to 51 cm (14 to 20 in); white (10YR 8/1) strongly cemented caliche, very pale brown (10YR 8/2) moist; massive; extremely hard, extremely firm; many fine and medium roots matted on top of laminar cap; laminar cap is 0.5 to 1.3 cm (1/4 to 1/2 in) thick; horizon is fractured in upper 5 cm (2 in); 5 percent very dark gray clay with few fine roots in fractures; violently effervescent; moderately alkaline; abrupt smooth boundary. (Thickness is 10 to 30 cm [4 to 12 in].)

CBk--51 to 117 cm (20 to 46 in); very pale brown (10YR 8/3) calcareous weakly cemented coarsely fractured siltsone bedrock of silt loam texture; pale brown (10YR 6/3) moist; massive; 35 percent films and threads of calcium carbonate along horizontal beds; 15 percent masses of calcium carbonate; common fine calcium carbonate filled krotovinas; violently effervescent; moderately alkaline; gradual wavy boundary. (Thickness is 0 to 117 cm [0 to 46 in].)

2Cr--117 to 203 cm (46 to 80 in); very pale brown (10YR 7/4) noncalcareous weakly cemented siltsone bedrock of silt loam texture, light yellowish brown (10YR 6/4) moist; massive; fractures 1.2 to 10 cm (1/2 to 4 in) apart, interstices have few threads and films of calcium carbonate that decrease with depth; common fine calcium carbonate filled krotovinas; moderately alkaline.

TYPE LOCATION: Karnes County, Texas; from the intersection of U.S. Highway 181 and Farm Road 1144 in Karnes City; 4.9 miles west on Farm Road 1144; 50 feet north in rangeland. Karnes city, Texas USGS topographic quadrangle; Latitude: 28 degrees, 52 minutes, 36 seconds N; Longitude: 97 degrees, 59 minutes, 02 seconds W.; NAD83.

RANGE IN CHARACTERISTICS:

Soil Moisture: A typic-ustic moisture regime. The soil moisture control section is dry in some or all parts for more than 90 days but less than 180 cumulative days in normal years. June through August and December through February are the driest months. These soils are intermittently moist in September through November and March through May.
Solum thickness and depth to a petrocalcic horizon: 25 to 50 cm (10 to 20 in)
Particle-size control section (weighted average)
clay content: 35 to 50 percent

Reaction: slightly alkaline or moderately alkaline and calcareous.

A Horizon
Hue: 10YR
Value: 2 to 4
Chroma: 1 or 2
Texture: Clay loam or Clay
Rock Fragments: 0 to 15 percent fine caliche fragments and calcium carbonate concretions
Reaction: slightly alkaline or moderately alkaline and calcareous

Bk Horizon
Hue: 10YR
Value: 3 to 6
Chroma: 1 or 2
Texture: gravelly clay loam or gravelly clay
Rock Fragments: 15 to 30 percent caliche fragments
Reaction: slightly alkaline or moderately alkaline and calcareous

Bkkm Horizon
Hue: 10YR or 2.5Y
Value: of 6 to 8
Chroma: 1 to 3
Cementation: weakly to strongly
Cemented caliche fragments range from 3 to 20 cm (1 to 8 in) across and 1/3 to 8 cm (1/8 to 3 in) thick

CBk Horizon (BCk where present)
Hue: 7.5YR, 10YR, or 2.5Y
Value of 7 or 8
Chroma of 0 to 3
Texture: silt loam or loam
Cementation: weakly consolidated caliche or calcareous siltstone
This layer slakes in water
Calcium carbonate equivalent: 20 to 50 percent
Identifiable secondary carbonates: 5 to 45 percent, fine to coarse, films, threads, and masses, 1 to 20 cm (1/2 to 8 in) apart and decrease in the lower part
Calcium carbonate filled krotovinas: few to many, fine and medium

2Cr Horizon (2Crk where present)
Hue: 7.5YR, 10YR, or 2.5Y
Value: 6 to 8
Chroma: 1 to 4
Texture: silt loam or loam
Fractured, noncalcareous, siltstone
This layer slakes in water
Identifiable secondary carbonates: few, thin, films and threads in the upper part of the layer

COMPETING SERIES: There are no competing series. Similar soils are the Condido (TX), Ecleto (TX), Fashing (TX), Kavett (TX), Mereta (TX), Olmos (TX), Valco (TX), Valera (TX), Weigang (TX) and Zorra (TX)series.
Condido soils: are noncalcareous in the solum
Ecleto soils: have argillic horizons
Fashing soils: do not have a petrocalcic horizon
Kavett, Mereta, Valera soils: have soil temperatures less than 22 degrees C (72 degrees F)
Olmos and Zorra soils: have loamy-skeletal control sections and carbonatic mineralogy
Valco soils: have loamy control sections and mixed mineralogy
Weigang soils: have loamy argillic horizons

GEOGRAPHIC SETTING:
Parent material: clayey sediments over noncalcareous weakly cemented siltstone bedrock interbedded with layers of soft calcium carbonate of the Catahoula Formation
Landscape: inland, dissected coastal plains
Landform: ridges
Slope: 0 to 5 percent
Mean annual air temperature range: (70 to 74 degrees F)
Mean annual precipitation range: (28 to 32 in)
Frost-free period: 275 to 290 days
Elevation: (350 to 475 ft)
Thornthwaite P-E indices: 31 to 44

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Condido (TX), Ecleto (TX), Eloso (TX), Fashing (TX), Rosenbrock (TX), Tordia (TX) and Weigang (TX) series.
Condido soils: are on similar positions and are noncalcareous in the solum
Ecleto soils: are on similar positions and have argillic horizons
Fashing soils: are on similar positions and do not have a petrocalcic horizon
Weigang soils: are on similar positions and have loamy argillic horizons
Eloso soils: are on similar or slightly lower positions, are clayey throughout and have sola more than 50 cm (20 in) thick
Rosenbrock soils: are on similar or slightly lower positions, are clayey throughout and have sola more than 50 cm (20 in) thick
Tordia soils: are on similar or slightly lower positions, are clayey throughout and have sola more than 50 cm (20 in) thick

DRAINAGE AND PERMEABILITY: Well drained. Runoff is low on 0 to 1 percent slopes and medium on 1 to 5 percent slopes. Permeability is slow.

USE AND VEGETATION: Used mainly as rangeland and wildlife habitat. Scattered areas are cultivated with small grain and grain sorghum. Some areas are used as bermudagrass pasture and hayland. Native grasses include Texas wintergrass, sideoats grama, bristlegrasses, silver bluestem, buffalograss, threeawns, and forbs. Woody vegetation is mainly agarito, prickly pear, lotebush, mesquite, spiny hackberry, persimmon, blackbrush, and live oak. (Shallow Ridge ecological site, PZ 20-32, R083AY409TX).

DISTRIBUTION AND EXTENT: Northern and Central Rio Grande Plain, Texas; LRR I; MLRA 83A and 83C. The series is of moderate extent.

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

SERIES ESTABLISHED: Karnes County, Texas 1989. The name is from a small community in northwest Karnes County.

REMARKS: These soils were formerly included in the Fashing, Monteola, Pettus, and Weigang series.
Diagnostic horizons and features recognized in this pedon are:
Particle size control section: 0 to 36 cm (0 to 14 in) (A, Bk horizons)

Mollic epipedon: 0 to 36 cm (0 to 14 in). (A, Bk horizons)

Calcic horizon: 18 to 51 cm (7 to 20 in). (Bk, Bkm horizons)

Petrocalcic horizon: 36 to 51 cm (14 to 20 in). (Bkm hroizon)

ADDITIONAL DATA: NSSL S86TX-255-001; NSSL Pedon Number: 87P-262.

SOIL INTERPRETATION RECORD NUMBER: TX1178

TAXONOMIC VERSION: Keys to Soil Taxonomy, Eleventh Edition, 2010

National Cooperative Soil Survey
U.S.A.