LOCATION SANDERSON TXEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, carbonatic, thermic Ustic Haplocambids
TYPICAL PEDON: Sanderson gravelly loam--rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 2 inches; light brownish gray (10YR 6/2) gravelly loam, dark grayish brown (10YR 4/2) moist; weak fine platy structure; slightly hard, very friable, slightly sticky and nonplastic; 30 percent angular limestone gravel, mostly 1/8 to 1 inch in diameter; slightly effervescent; moderately alkaline; clear smooth boundary. (0 to 3 inches thick)
A2--2 to 9 inches; light brownish gray (10YR 6/2) gravelly loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky and granular structure; slightly hard, very friable, slightly sticky and nonplastic; 30 percent angular limestone gravel, mostly 1/4 to 2 inches in diameter; few masses, films and threads of calcium carbonate; strongly effervescent; moderately alkaline; gradual smooth boundary. (5 to 18 inches thick)
Bk--9 to 28 inches; pale brown (10YR 6/3) very gravelly loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; 35 percent limestone gravel, mostly 1/4 to 2 inches across, 5 percent limestone cobbles; few masses, films and threads of calcium carbonate; violently effervescent; moderately alkaline; diffuse smooth boundary. (10 to 20 inches thick)
C--28 to 60 inches; very pale brown (10YR 7/3) very gravelly loam, brown (10YR 5/3) moist; massive; slightly hard, very friable, slightly sticky and nonplastic; 40 percent angular limestone gravel, 5 percent limestone cobbles; violently effervescent; moderately alkaline.
TYPE LOCATION: Terrell County, Texas: From the junction of U.S. Highways 90 and 285 in Sanderson, north one mile to highway culvert, then from the southeast corner of the culvert 200 feet to the southeast. (Latitude: 30 degrees, 09 minutes, 37 seconds North; Longitude: 102 degrees, 24 minutes, 30 seconds, West).
RANGE IN CHARACTERISTICS: Solum thickness ranges from 24 to more than 40 inches. Amount of coarse fragments in the control section ranges from 35 to 80 percent by volume and is 30 to 70 percent gravel, 0 to 20 percent cobbles, and 0 to 10 percent stones. Clay content ranges from 18 and 35 percent. Visible forms of calcium carbonate range from none to about 4 percent by volume.
The A horizon has hue of 7.5YR, 10YR, or 2.5Y, value of 5 to 7, and chroma of 2 to 4. Texture is gravelly or very gravelly loam, sandy loam, or clay loam. Coarse fragments range from 15 to 50 percent, and comprise 15 to 50 percent gravel, 0 to 20 percent cobbles, and 0 to 10 percent stones.
The Bk horizon has hue of 10YR or 7.5YR, value of 5 to 7, and chroma of 2 to 4. Texture is very gravelly loam, very gravelly clay loam, or very gravelly sandy clay loam. Films, threads and concretions of calcium carbonate range from none to few.
The C or CBk horizon has hue of 10YR or 7.5YR, value of 6 to 8, and chroma of 2 to 4. Texture is very gravelly loam, very gravelly sandy loam, or very gravelly clay loam.
COMPETING SERIES: There are no other series in the same family. Similar soils are the Cienega, Gallegos, Stillwell and Vado series. Cienega soils have calcic horizons. Gallegos and Vado soils have mixed mineralogy. Stillwell soils have less organic matter in the surface horizons and have calcic horizons.
GEOGRAPHIC SETTING: Sanderson soils are mainly on footslopes and alluvial fans below limestone hills and, in a few places, in flood plains of streams that drain these hills. Slope gradients range from 0 to about 8 percent. The soils formed in gravelly alluvium and colluvium derived from limestone rocks. Mean annual temperature ranges from 60 to 70 degrees F., and mean annual precipitation ranges from 11 to 20 inches. Frost-free period ranges from 210 to 260 days and elevation ranges from 1,100 to 4,000 feet. Thornthwaite P-E indices range from 16 to 28.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Conger, Ector, Hodgins, Lozier, Reagan, and Upton series. Conger soils are shallow to indurated caliche and are in similar or slightly higher convex positions. Ector and Lozier soils are shallow over limestone and are on higher ridges and mountain sideslopes. Hodgins and Reagan soils have less than 35 percent coarse fragments in the control section and are below in broad flats or drainageways. Upton soils are dry for longer periods of time and are shallow to indurated caliche and are in similar or slightly higher convex positions.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is negligible on slopes less than 1 percent, very low on 1 to 3 percent slopes, low on 3 to 5 percent slopes, and medium on 5 to 8 percent slopes.
USE AND VEGETATION: Native range of low carrying capacity. Desert grassland type vegetation. Vegetation consists of thin overstory of creosotebush, juniper, and mesquite shrubs and a sparse cover of treeawns.
DISTRIBUTION AND EXTENT: Western and Southwestern Texas (81A, 81D) and probably southern New Mexico. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Jeff Davis County, Texas; 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 9 inches. (A1 and A2 horizons)
Cambic horizon - 9 to 28 inches. (Bk horizon)
Ustic feature - The soil has an aridic moisture regime that borders on the ustic regime.
ADDITIONAL DATA:
TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006