LOCATION CASTELL TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, semiactive, thermic Typic Paleustalfs
TYPICAL PEDON: Castell sandy loam - rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 8 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; very hard and massive when dry, very hard, friable; common fine roots and pores; few fine fragments of angular quartz; slightly acid; clear smooth boundary. (6 to 18 inches thick)
Bt1--8 to 17 inches; yellowish brown (10YR 5/4) sandy clay, yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; very hard, firm; common fine roots and pores; thin patchy clay films on ped surfaces; few fine and medium fragments of quartz and gneiss; slightly acid; clear smooth boundary. (8 to 22 inches thick)
Bt2--17 to 30 inches; strong brown (7.5YR 4/6) sandy clay, strong brown (7.5YR 4/6) moist; common fine distinct reddish yellow (7.5YR 6/6) and yellowish brown (10YR 5/6) mottles; moderate medium subangular block structure; very hard, firm, few fine roots and pores; thin patchy clay films on ped surfaces; few fine and medium fragments of gneiss and quartz; medium acid; abrupt smooth boundary. (0 to 15 inches thick)
Cr--30 to 42 inches; weathered pinkish gneiss, that becomes harder with depth.
TYPE LOCATION: Llano County, Texas; about 10 miles west of Llano, Texas; from intersection of Texas Highways 29 and Texas Highway 16 in Llano, 9.7 miles west on Texas Highway 29, 120 feet south of highway rangeland.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 20 to 40 inches and is underlain by weathered gneiss bedrock. Coarse fragments throughout the solum ranges from 5 to about 30 percent volume, consisting mostly of angular feldspar, gneiss and quartz. Base saturation ranges from 75 to 100 percent.
The A horizon has hue of 5YR, 7.5YR, or 10YR, value of 4 or 5, and chroma of 2 to 4. Texture is sandy loam or loamy sand and also their gravelly counterparts. Clay content averages 6 to 20 percent. Organic matter content ranges from 0.3 to 0.9 percent. Boundary between the A and Bt horizon ranges from clear to abrupt. Reaction ranges from moderately acid to neutral.
The Bt horizon has hue of 7.5YR or 10YR, value of 4 to 6 and chroma of 3 to 6. Redoximorphic features with hue of 2.5YR to 10YR, value of 4 to 6, and chroma of 3 to 6 range from none to common. These features are interpreted as relict, or inherited from the parent material. Texture is clay loam, clay or sandy clay and also their gravelly counterparts. Clay content ranges from 35 to 50 percent. Reaction ranges from moderately acid to slightly alkaline.
The Cr horizon ranges from weathered gneiss (saprolitic) to relatively unweathered and finely fractured gneiss.
COMPETING SERIES: These include the Hamby, Pedernales, Shatruce, Voca, Weswind, and Winters. All of these soils, except Shatruce soils, have solum thicker than 40 inches, and all the soils formed from material other than gneiss. In addition, the Pedernales and Winters soil have secondary carbonates in the lower part of the solum, and Shatruce soils have hue of 5YR or redder in the argillic horizon. Voca soils developed from granite grus, and Weswind soils developed in interbedded redbed shale and sandstone.
GEOGRAPHIC SETTING: The Castell soils occur on uplands. Slope gradient range from 0 to 5 percent. The soils formed in residuum weathered from gneiss. Mean annual precipitation ranging from 24 to 30 inches, and mean annual air temperature of 65 degrees to 67 degrees F. Frost free days range from 215 to 230, and elevation ranges 1,100 to 1,500 feet. Thornthwaite P-E Index ranges from 38 to about 44.
GEOGRAPHIC ASSOCIATED SOILS: These include the Katemcy, Keese, Ligon, and Voca series. Katemcy soils do not have an abrupt texture change between the A and Bt horizon and are over schist. Keese soils do not have an argillic horizon and are shallow over gneiss or granite bed rock. Ligon soils are over schist.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow. Runoff is low on slopes less than 1 percent and medium on 1 to 5 percent slopes.
USE AND VEGETATION: Used mainly for rangeland. Small areas farmed to small grain and sorghums for grazing and hay. Native vegetation consists of little bluestem, purpletop, sand lovegrass, and sideoats grama grasses with scattering of post oak and live oak trees. In many places the vegetation is mesquite trees, whitebrush, Texas persimmon trees, tasajillo, grasses such as threeawn, sand dropseed, fringeleaf paspalum, and numerous forbs.
DISTRIBUTION AND EXTENT: In the Central Basin of Texas, possibly in south-central Oklahoma. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Gillespie County, Texas; 1970
REMARKS: Diagnostic horizons and features recognized in pedon are:
Ochric epipedon - 0 to 8 inches. (A horizon)
Argillic horizon -8 to 30 inches. (Bt horizon)
Abrupt texture change between A and Bt horizons.
Paralithic contact at 30 inches.
ADDITIONAL DATA: Stanke, Clyde, 1965, A Study of Mineral Transformations and Weathering Processes Occurring during the Genesis of Two Soils developed from Gneiss and Schist in Llano County, Texas; May 1965, Masters thesis, Texas Technological College, Lubbock, Texas.