LOCATION ROSENBROCK              TX

Established Series
Rev. NLM-RM-GWH
11/2013

ROSENBROCK SERIES

The Rosenbrock series consists of deep and very deep, well drained, very slowly permeable soils on nearly level to very gently sloping, plane to slightly convex surfaces on low ridges. These soils formed from clayey alluvium over loamy residuum derived from noncemented tuffaceous siltstone of the Catahoula formation. Slope ranges from 0 to 3 percent. Mean annual precipitation is about 610 mm (24 in) and mean annual temperature is about 22.2 degrees C (72 degrees F).

TAXONOMIC CLASS: Fine, smectitic, hyperthermic Typic Haplusterts

TYPICAL PEDON: Rosenbrock clay in pastureland; elevation is 126 meters (414 feet). (Colors are for dry soils unless otherwise stated)

A--0 to 20 cm (0 to 8 in); very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; moderate medium subangular blocky structure; very hard, firm, very sticky, very plastic; many fine roots; common fine tubular pores; few fine snail shell fragments; slightly alkaline; clear smooth boundary. Thickness is 10 to 38 cm (4 to 15 in)

Bw--20 to 46 cm (8 to 18 in); very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; moderate medium prismatic structure parting to moderate medium angular blocky; very hard, very firm, very sticky, very plastic; common fine roots; common fine tubular pores; few fine masses of calcium carbonate; common distinct pressure faces; slightly effervescent; slightly alkaline; gradual wavy boundary. Thickness is 20 to 53 cm (8 to 21 in)

Bkss1--46 to 79 cm (18 to 31 in); very dark gray (10YR 3/1) clay, very dark gray (10YR 3/1) moist; moderate medium prismatic structure parting to moderate medium angular blocky; very hard, very firm, very sticky, very plastic; common fine roots; few fine tubular pores; common distinct pressure faces; few distinct slickensides; common fine masses and few fine concretions of calcium carbonate; strongly effervescent; slightly alkaline; gradual wavy boundary.

Bkss2--79 to 109 cm (31 to 43 in); grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; moderate fine and medium angular blocky structure; very hard, very firm, very sticky, very plastic; few fine roots; few fine tubular pores; common distinct pressure faces; few distinct slickensides; common fine and medium masses of calcium carbonate; common worm casts filled with very dark gray material; violently effervescent; moderately alkaline; clear wavy boundary. Combined thickness of the Bkss horizon is 38 to 119 cm (15 to 47 in)

2C/Bk--109 to 157 cm (43 to 62 in); very pale brown (10YR 7/3) noncemented tuffaceous siltstone with loam texture (C), pale brown (10YR 6/3) moist; 20 percent dark grayish brown (10YR 4/2) silty clay (Bk), grayish brown (10YR 5/2) slightly hard, friable, slightly sticky, slightly plastic; few fine roots; Bk material has common worm casts; violently effervescent; slightly alkaline; gradual smooth boundary. Thickness is 0 to 76 cm (0 to 30 in)

2Cdk--157 to 203 cm (62 to 80 in); very pale brown (10YR 7/3) noncalcareous noncemented tuffaceous siltstone bedrock with silt loam texture, pale brown (10YR 6/3) moist; massive; common medium soft masses and few fine and medium rounded nodules of calcium carbonate; violently effervescent; slightly alkaline.

TYPE LOCATION: Karnes County, Texas; from the intersection of U.S. Highway 181 and Farm Road 99 in Karnes City; 11.1 miles west on Farm Road 99; 400 feet south in pastureland. Coy City, Texas USGS topographic quadrangle; Latitude: 28 degrees, 48 minutes, 26 seconds N; Longitude: 98 degrees, 4 minutes, 16 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.
Depth to Densic bedrock: 112 to 195 cm (44 to 77 in)
Solum thickness: 102 to 152 cm (40 to 60 in).
Vertic features: Few distinct slickensides are at a depth of 30 to 91 cm (12 to 36 in).
Cracks: up to 3 cm (1 in) wide, when dry, that extend to a depth of more than 51 cm (20 in).
Reaction: slightlyalkaline or moderately alkaline.

A Horizon:
Hue: 10YR
Value: 2 or 3
Chroma: 1
Texture: silty clay or clay
Clay content: 40 to 50 percent
Identifiable secondary carbonate: 0 to 2 percent; less than 2 mm; concretions
Calcium carbonate equivalent: 0 to 2 percent
Electrical conductivity: 0 to 2 dS/m
Sodium absorption ratio: 0 to 1
Reaction: slightly alkaline to moderately alkaline

Bw Horizon:
Hue: 10YR
Value: 2 to 6
Chroma: 1 to 3
Texture: silty clay or clay
Clay content: 45 to 60 percent
Identifiable secondary carbonate: 0 to 15 percent; 3 to 7 mm (1/8 to 1/4 in); masses and concretions
Calcium carbonate equivalent: 5 to 20 percent
Electrical conductivity: 0 to 4 dS/m
Sodium absorption ratio: 0 to 1
Reaction: slightly alkaline to moderately alkaline

Bkss Horizons:
Hue: 10YR
Value: 3 to 7
Chroma: 1 to 4
Texture: silty clay or clay
Clay content: 45 to 60 percent
Identifiable secondary carbonate: 5 to 15 percent; 3 to 7 mm (1/8 to 1/4 in); masses and concretions
Calcium carbonate equivalent: 5 to 20 percent
Electrical conductivity: 0 to 4 dS/m
Sodium absorption ratio: 0 to 2
Reaction: slightly alkaline to moderately alkaline

BCk Horizon: (where present)
Hue: 7.5YR or 10YR
Value: 3 to 5
Chroma: 1 to 3
Texture: clay loam, clay, silty clay
Clay content: 35 to 55 percent
Identifiable secondary carbonate: 5 to 15 percent; masses
Calcium carbonate equivalent: 25 to 35 percent
Electrical conductivity: 2 to 8 dS/m
Sodium absorption ratio: 2 to 8
Reaction: slightly alkaline to moderately alkaline

2C/Bk Horizon:
Hue: 7.5YR or 10YR
Value: 4 to 8
Chroma: 1 to 4
Texture: 2C part is noncemented tuffaceous siltstone that slakes in water with loam or silt loam texture
Texture: Bk part is clay, silty clay, or clay loam
Clay content: 20 to 45 percent
Calcium carbonate equivalent: 25 to 35 percent
Electrical conductivity: 2 to 8 dS/m
Sodium absorption ratio: 2 to 8
Reaction: slightly alkaline to moderately alkaline

2Cdk Horizon:
Hue: 10YR or 7.5YR
Value: 6 to 8
Chroma: 2 to 4
Texture: noncemented tuffaceous siltstone that slakes in water and has loam or silt loam texture, interbedded with thin layers of calcium carbonate
Clay content: 10 to 26 percent
Excavation difficulty: can be dug with low to moderate difficulty
Calcium carbonate equivalent: 5 to 30 percent
Electrical conductivity: 2 to 8 dS/m
Sodium absorption ratio: 4 to 16
Reaction: slightly alkaline to moderately alkaline

COMPETING SERIES: These include the Buchel (TX), Danjer (TX), Lattas (TX), Monteola (TX), Realitos (TX), and Tordia (TX) series. Similar soils include the Coy (TX) and Eloso (TX) series.
Buchel soils: formed in alluvium on nearly level flood plains; are not underlain with tuffaceous siltstone bedrock
Danjer and Lattas soils: are not underlain with tuffaceous siltstone bedrock
Monteola soils: are not underlain with tuffaceous siltstone bedrock; have gypsum accumulations in the lower part of the control section
Eloso soils: moderately deep to tuffaceous bedrock
Tordia soils: deep over sandstone and claystone bedrock;
Coy soils: have an argillic horizon
Realitos soils: are not underlain with tuffaceous siltstone bedrock

GEOGRAPHIC SETTING:
Parent material: clayey alluvium over loamy residuum derived from noncemented tuffaceous siltstone interbedded with thin layers of soft calcium carbonate of the Catahoula formation
Landscape: inland, dissected coastal plain
Landform: back slopes, foot slopes, and toe slopes of low ridges and broad interfluves
Slope: 0 to 3 percent
Mean annual precipitation range: 660 to 914 mm (26 to 36 in)
Precipitation pattern: June through August and December through February are the driest months. These soils are intermittently moist in September through November and March through May.
Thornthwaite P-E indices: 31 to 44
Mean annual air temperature range: 2.11 to 22.8 degrees C (70 to 73 degrees F)
Frost-free period: 275 to 290 days
Elevation: 99.1 to 152.4 m (325 to 500 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Clareville, Condido, Eloso, Pavelek, and Tordia series.
Clareville soils: have an argillic horizon and occur on a stream terrace
Condido and Pavelek soils: are less than 51 cm (20 in) to a petrocalcic horizon and occur on higher positions
Eloso soils: have sola less than 100 cm (40 in) thick and occur on a higher position
Tordia soils: occur on similar or slightly higher positions

DRAINAGE AND PERMEABILITY: Well drained. Permeability is very slow. Runoff is high on 0 to 1 percent slopes and very high on 1 to 3 percent slopes.

USE AND VEGETATION: Used mainly as rangeland and wildlife habitat. Some areas are cultivated with small grains, corn, wheat, and grain sorghum. Some areas are used as bermudagrass pasture and hayland. Native grasses include Texas wintergrass, sideoats grama, bristlegrasses, Hall's panicum, Texas grama, threeawns, and red grama. Woody vegetation is mainly agarito, prickly pear, lotebush, mesquite, spiny hackberry, persimmon, blackbrush, and live oak. The ecological site it Rolling Blackland 25-35" PZ (R083AY399TX).

DISTRIBUTION AND EXTENT: Northern Rio Grande Plain, Texas; LRR I, MLRA 83A; moderate extent.

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

SERIES ESTABLISHED: Karnes County, Texas 1989. The name is from a uranium mine site in southwest Karnes County.

REMARKS: These soils were formerly included with the Coy, Monteola, and Tordia series. Classification changed to Typic Haplusterts 9/97.

The 2Cr layer was changed to a 2Cdk horizon during the correlation of McMullen County. This decision was supported by the observation that the weakly consolidated tuffaceous siltstone bedrock slaked in water, probably due to increased weathering and landscape position. Tuffaceous siltstone bedrock in areas higher in the landscape is less weathered, retain more rocklike structure, and do not slake in water.

Edited 11/2013 (RFG-GWH): Chemical property ranges were added to the RIC; Competing series, geographic setting, and associated soils sections were updated.

Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 79 cm (0 to 31 in). (A, Bw, and Bk1 horizons)
Cambic horizon: 20 to 109 cm (8 to 43 in). (Bw, Bkss1, and Bkss2 horizons)
Vertic feature: presence of cracks when dry are up to 3 cm (1 in) wide and extend to more than 51 cm (20 in) in depth and the presence of slickenslides at 46 to 109 cm (18-43 in). (Bkss1 and Bkss2 horizons)
Densic contact: 157 cm (62 in). (top of 2Cdk horizon)
Densic material: 157 to 203 cm (62 to 80 in). (2Cdk horizon)

ADDITIONAL DATA: Karnes County, Texas; TAMU Characterization lab number S88TX-255-006.

Taxonomic version: Keys to Soil Taxonomy, Eleventh Edition, 2010

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National Cooperative Soil Survey
U.S.A.