LOCATION MATA                    TX

Established Series
Rev. WJG-RM-GWH
11/2010

MATA SERIES

The Mata series consists of soils that are deep to mudstone bedrock. These well drained, moderately permeable soils formed in the Uvalde Gravel overlying mudstone. They are nearly level to gently sloping soils on noseslopes and summits of interfluves. Slope ranges from 0 to 5 percent. Mean annual temperature is about 72 degrees F., and mean annual precipitation is about 21 inches.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, hyperthermic Aridic Calciustepts

TYPICAL PEDON: Mata gravelly sandy clay loam in rangeland; elevation is 105 meters (345 feet). (Colors are for dry soils unless otherwise stated.)

A--0 to 18 cm (0 to 7 in); pale brown (10YR 6/3) gravelly sandy clay loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; few fine irregular threads and fine rounded masses of calcium carbonate; 20 percent rounded siliceous pebbles mainly 0.25 to 2 inches in diameter; electrical conductivity (EC) is 0.5 dS/m; 8 percent calcium carbonate equivalent; strongly effervescent; slightly alkaline; clear smooth boundary. (Thickness is 10 to 25 cm [4 to 10 in].)

Bk--18 to 41 cm (7 to 16 in); pale brown (10YR 6/3) very gravelly clay loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; hard, friable, sticky and plastic; few very fine roots; few fine irregular threads and fine rounded weakly cemented nodules of calcium carbonate; 60 percent rounded siliceous pebbles mainly 1 to 3 inches in diameter with common prominent coats of calcium carbonate; EC is 0.7 dS/m; 21 percent calcium carbonate equivalent; violently effervescent; slightly alkaline; gradual wavy boundary. (Thickness is 20 to 56 cm [8 to 22 in].)

Bkz1--41 to 64 cm (16 to 25 in); light yellowish brown (10YR 6/4) extremely gravelly clay loam, yellowish brown (10YR 5/4) moist; weak fine subangular blocky structure; hard, friable, sticky and plastic; few very fine roots; few fine irregular threads and fine rounded weakly cemented nodules of calcium carbonate; 65 percent rounded siliceous pebbles with few distinct coatings of calcium carbonate; EC is 5.0 dS/m; 22 percent calcium carbonate equivalent; violently effervescent; slightly alkaline; clear wavy boundary. (Thickness is 0 to 51 cm [0 to 20 in].)

Bkz2--64 to 107 cm (25 to 42 in); very pale brown (10YR 7/4) fine sandy loam, light yellowish brown (10YR 6/4) moist; weak fine subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine roots; 20 percent fine irregular threads and fine to coarse rounded masses of calcium carbonate; 10 percent rounded siliceous pebbles with few distinct coats of calcium carbonate; EC is 11.0 dS/m; 28 percent calcium carbonate equivalent; violently effervescent; moderately alkaline; gradual wavy boundary. (Thicknes is 20 to 56 cm [8 to 22 in].)

Bkz3--107 to 137 cm (42 to 54 in); very pale brown (10YR 7/4) gravelly sandy loam, light yellowish brown (10YR 6/4) moist; weak fine subangular blocky structure; slightly hard, friable; few very fine roots; 30 percent fine irregular threads and fine to coarse rounded masses of calcium carbonate; few mudstone fragments in lower part; 15 percent rounded siliceous pebbles with few distinct coats of calcium carbonate; EC is 11.0 dS/m; 32 percent calcium carbonate equivalent; violently effervescent; moderately alkaline; abrupt wavy boundary. (Thickness is 0 to 36 cm [0 to 14 in].)

2Cdyz--137 to 183 cm (54 to 72 in); pale yellow (5Y 8/2) fractured noncemented shale bedrock; light gray (5Y 7/2) moist; few fine faint yellow mottles; massive; very hard, friable; the mudstone slakes in water; extremely hard, very firm; common fine and medium irregular masses of gypsum crystals and other salts; violently effervescent; moderately alkaline.

TYPE LOCATION: La Salle County, Texas; from Cotulla, 0.8 mile east on Texas Highway 97; 20.8 miles southeast on Farm Road 624 (0.8 mile east of junction with county road to south); 50 feet north of fence in rangeland. Caiman Creek NE, Texas USGS topographic quadrangle; Latitude: 28 degrees, 12 minutes, 15.45 seconds N; Longitude: 99 degrees, 1 minute, 34.94 seconds W.: NAD 83.

RANGE IN CHARACTERISTICS:

Soil Moisture: An aridic ustic moisture regime. The soil moisture control section is moist in some or all parts for less than 90 consecutive days in normal years. June to August and December to February are the driest months, while September to November and March to May are the wettest months.
Mean annual soil temperature: 22 to 24 degrees C (72 to 76 degrees F)
Depth to paralithic contact: 100 to 150 cm (40 to 60 in)
Depth to calcic horizon: 13 to 100 cm (5 to 40 in)

Particle-size control section (weighted average)
Silicate clay content: 20 to 40 percent
Coarse Fragments: 35 to 60 percent
CEC/clay ratio: 0.60 to 0.90

A horizon
Hue: 7.5YR or 10YR
Value: 4 to7
Chroma: 2 to 4
Texture: sandy clay loam, clay loam, or their gravelly counterparts
Clay content: 18 to 35 percent
Coarse fragments: 5 to 35 percent
Base saturation: 90 to 100 percent
Calcium carbonate equivalent: 3 to 20 percent
Identifiable secondary carbonate: none to few, very fine and fine, films and threads
EC (dS/m): 0.4 to 1.0
Gypsum: 0 to 1 percent
SAR: 0 to 12
Effervescence: slight or strong
Reaction: slightly alkaline or moderately alkaline

Bk and Bkz horizons
Hue: 7.5YR or 10YR, 2.5Y
Value: 5 to 8
Chroma: 1 to 4
Texture: fine sandy loam, sandy loam, loam, sandy clay loam, or clay loam
Total clay content: 20 to 40 percent
Silicate clay content: 20 to 35 percent
Coarse fragments: 35 to 60 percent
Base saturation: 100 percent
Calcium carbonate equivalent: 5 to 40 percent
Identifiable secondary carbonate: few to many, fine to coarse, films, threads, masses, and concretions
EC (dS/m): 0.4 to 6.0 in the upper part ranging to 4.0 to 16.0 in the lower part
Gypsum: 0 to 1 percent
SAR: 0 to 12 in the upper part ranging to 0 to 20 in the lower part
Effervescence: strong or violent
Reaction: slightly alkaline or moderately alkaline

2Cdyz horizon:
Hue: 5YR, 7.5YR or 10YR
Value: 5 to 8
Chroma: 1 to 5
Texture: silty clay, silty clay loam, clay or clay loam
Gypsum: 1 to 10 percent
Effervescence: slight to violent
Reaction: slightly alkaline or moderately alkaline

COMPETING SERIES: There are no competing series in the same family. Similar soils are the Aguilares (TX), Grava (TX), Hindes (TX), Mirasol (TX), and Moglia (TX) series.

Aguilares and Moglia soils: are not in the skeletal family, and do not have shale bedrock within 80 inches of the surface
Grava soils: have a mollic epipedon and are 51 to 102 cm (20 to 40 in) to a petrocalcic horizon
Hindes soils: are in the clayey-skeletal family, are very deep and have a mollic epipedon
Mirasol soils: are less than 51 cm (20 in) to weathered sandstone

GEOGRAPHIC SETTING:
Parent material: gravelly alluvium assumed to be the Uvalde Gravel, overlying weathered shale bedrock
Landscape: inland, dissected coastal plains
Landform: ridges and interfluves
Slope: 0 to 5 percent
Mean annual air temperature: 70 to 74 degrees F.
Mean annual precipitation: 17 to 25 inches
Precipitation pattern: moist spring and fall months and dry summer and winter months
Frost-free period: 280 to 360 days
Elevation: 400 to 750 feet
Thornthwaite annual P-E indices: 25 to 34

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aguilares (TX), Catarina (TX), Cotulla (TX), Lasalle (TX), Maverick (TX), Moglia (TX), and Salco (TX) series.

Aguilares soils: occur on similar to slightly lower landscape positions
Catarina,Cotulla and Lasalle soils: occur in the lower parts of the landscape; have sola greater than 102 cm (40 in); do not have coarse fragments; are clayey
Maverick soils: occur on similar to slightly lower elevations
Moglia soils: occur on slightly lower elevations
Salco soils: are in the fine-loamy family, have a mollic epipedon; occur on lower footslope positions

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is negligible on 0 to 1 percent slopes, very low on 1 to 3 percent slopes, and low on 3 to 5 percent slopes.

USE AND VEGETATION: This soil is used for range and wildlife habitat. The native vegetation include grasses such as red grama, threeawn, Hall's panicum and bristlegrass. Woody plants include blackbrush, guajillo, guyacan, lotebush condalia, whitebrush, tasajillo, pricklypear cacti; vine ephedra, paloverde with a few mesquite, and creosote bush. Some broomweed and other forbs occur.

DISTRIBUTION AND EXTENT: Western Rio Grande Plain, Texas; LRR I; MLRA 83B; The series is of minor extent.

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

SERIES ESTABLISHED: La Salle County, Texas, 1984; The name is from a small lake (La Mata Lake) near the type location.

REMARKS: Classification change from Haplocalcidic Ustochrepts to Aridic Calciustepts based on application of the second edition of Soil Taxonomy, 1999.

Diagnostic horizons and features recognized in this pedon are:

Particle size control section: 10 to 40 inches.

Ochric epipedon: 0 to 18 cm (0 to 7 in). (A horizon)

Calcic horizon: 64 to 137 cm (25 to 54 in). (Bk and Bkz horizons)

Densic contact: The contact with mudstone bedrock at 137 cm (54 in). (2Cdyz horizon)

Lithologic discontinuity: At the upper boundary of the 2Cdyz horizon.

Mottles in the 2Cdyz horizon are considered to be lithochromic.

The assignment of the cation-exchange activity class is inferred from lab data from surrounding counties in the region. Laboratory data from La Salle County is inconclusive.

ADDITIONAL DATA: TAMU Soil Characterization Laboratory data from 2 pedons in La Salle County, Texas (S85TX-283-01; S85TX-283-02). Particle-size analysis, pH tests were performed at the project office on 1 pedon in McMullen County, Texas.

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

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National Cooperative Soil Survey
U.S.A.