LOCATION TASCOSA TXEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Aridic Calciustolls
TYPICAL PEDON: Tascosa gravelly loam, north-facing, convex, 4 percent slope in rangeland at an elevation of about 3,200 feet. (Colors are for dry soil unless otherwise stated.)
A--0 to 9 inches; brown (7.5YR 5/2) very gravelly loam, dark brown (7.5YR 3/2); moist; weak fine subangular blocky structure parting to granular; slightly hard, friable; many roots; about 35 percent of 5 to 20 mm diameter medium quartzite gravel; about 50 percent of soil surface is covered with gravel; few wormcasts; strongly effervescent; moderately alkaline; clear smooth boundary. (7 to 12 inches thick)
Bk--9 to 13 inches; pinkish gray (7.5YR 6/2) extremely gravelly loam, brown (7.5YR 4/2) moist; weak fine granular structure; soft, very friable; common fine and medium roots; about 10 percent calcium carbonate films, threads, and coatings on the underside of quartzite gravel; about 60 percent of 7 to 20 mm diameter medium quartzite gravel; strongly effervescent; moderately alkaline; clear smooth boundary. (3 to 10 inches thick)
Ck--13 to 20 inches; pinkish gray (7.5YR 6/2) extremely gravelly loam, brown (7.5YR 4/2) moist; single grain; soft, very friable; few fine roots; about 50 percent calcium carbonate masses and coatings on the underside of quartzite gravel; about 60 percent of 5 to 20 mm diameter medium quartzite gravel; violently effervescent; moderately alkaline; gradual smooth boundary. (5 to 20 inches thick)
C--20 to 80 inches; pink (7.5YR 7/4) very gravelly sandy loam, reddish yellow (5YR 6/6) moist; single grain; loose, very friable; about 50 percent of 5 to 20 mm diameter medium quartzite gravel; violently effervescent; moderately alkaline.
TYPE LOCATION: Moore County, Texas; from the intersection of U.S. Highway 87 and county road 1913 in Fourway, 12.5 miles east on county road 1913, 3.5 miles south on Plum Creek Road to the south entrance to the Weymouth Ranch on the east side of Plum Creek Road, 2.2 miles east on county road to gate; 400 feet east and 400 feet south on the west side of the ranch road in rangeland; Latitude: 35 degrees, 38 minutes, 5.1 seconds N; Longitude: 101 degrees, 42 minutes, 11 seconds W; Evans Canyon, Texas USGS quad; NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture: An ustic moisture regime bordering on aridic. The soil moisture control section is dry in some or all parts for more than 180 but less than 205 days, cumulative, in normal years. October through March are the driest months. These soils are intermittently moist in April through September.
Mean annual soil temperature: 59 to 65 degrees F.
Depth to secondary carbonates: 0 to 26 inches.
Depth to quartzite gravel: 0 to 80 inches.
Solum thickness: 10 to 22 inches
Particle-size control section: 10 to 18 percent silicate clay.
A horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3
Texture: gravelly loam, sandy loam, fine sandy loam, loam
Coarse fragments: 20 to 40 percent quartzite gravel
Effervescence: strong or violent
Reaction: slightly or moderately alkaline
Note: about 50 percent of soil surface is covered with quartzite gravel.
Bk horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 4
Texture: sandy loam, fine sandy loam, loam
Coarse fragments: 20 to 60 percent quartzite gravel
Visible calcium carbonate: 5 to 30 percent in the form of films, threads, and coatings on the underside of quartzite gravel
Effervescence: strong or violent
Reaction: slightly or moderately alkaline
Ck horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 4
Texture: loamy sand, sandy loam, loam
Coarse fragments: 20 to 60 percent quartzite gravel
Visible calcium carbonate: 5 to 30 percent in the form of masses and coatings on the underside of quartzite gravel
Calcium carbonate equivalent: 20 to 60 percent.
Effervescence: strong or violent
Reaction: slightly or moderately alkaline
C horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 4
Texture: sandy loam, fine sandy loam
Coarse fragments: 35 to 80 percent quartzite gravel
Effervescence: strong or violent
Reaction: slightly or moderately alkaline
Note: These soils are very gravelly to more than 6 feet deep in many pedons. In some pedons reddish clay loam or shaly materials are below 40 inches.
COMPETING SERIES: This is the
Hathaway series. Similar soils are the
Gallegos,
Hilgrave,
Pena,
Polar,
Potter, and
Veal series.
Hathaway series: formed in fan alluvium from mixed sources of limestone, rhyolite, granite, dacite, andesite, tuff, quartzite, sandstone, and shale.
Gallegos and Polar series: have an ochric epipedon and in addition, Gallegos series is noncalcareous in the upper 7 inches.
Hilgrave series: has an argillic horizon and is noneffervescent in the A and upper Bt horizons.
Potter series: has carbonatic soil mineralogy.
Veal series: have less than 5 percent siliceous gravel and carbonatic soil mineralogy.
Pena series: have a thicker mollic epipedon and cobbly or stony AC and C horizons.
GEOGRAPHIC SETTING:
Parent material: sandy and gravelly alluvial sediments of the Ogallala Formation of Miocene-Pliocene age.
Landform: convex, gently sloping to steep knobs and erosional hillslopes in the Canadian Breaks and margins of the Southern High Plains (MLRA 77E).
Slopes: dominantly 3 to 30 percent.
Mean annual air temperature: 57 to 63 degrees F.
Mean annual precipitation: 17 to 23 inches.
Frost-free period: 175 to 220 days.
Elevation: 2,200 to 4,800 feet.
Thornthwaite annual P-E Index Values: 30 to 34.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Ady,
Berda,
Guadalupe,
Mobeetie
Likes,
Plemons,
Potter,
Springer, and
Veal series.
Ady soils are on slightly higher landscape positions and have an ochric epipedon and an argillic horizon.
Berda and Veal soils are on similar hillslope landscape positions and have an ochric epipedon and a fine loamy particle-size control section.
Guadalupe soils are on lower landscape positions on floodplains and have coarse loamy particle-size class.
Mobeetie and Likes soils are on similar hillslope landscape positions and have an ochric epipedon and a coarse-loamy particle-size control section.
Springer soils are on lower landscape positions and have an ochric epipedon and an argillic horizon.
Potter soils are on higher landscape positions and have carbonatic soil mineralogy.
DRAINAGE AND PERMEABILITY: Well drained. Moderate permeability. Surface runoff is low on 3 to 5 percent slopes, medium on 5 to 20 percent slopes, and high on greater than 20 percent slopes.
USE AND VEGETATION: This soil is primarily used for rangeland and wildlife and supports stands of little bluestem, black grama, hairy grama, sideoats grama, blue grama, and sand dropseed with some catclaw and yucca. It produces low amounts of forage. This soil has been correlated to the Mixedland Slope (077EY061TX) range site in MLRA-77E.
DISTRIBUTION AND EXTENT: Canadian Breaks and margins of the Southern High Plains of western Texas, possibly extending into Oklahoma and New Mexico (MLRA-77E in LRR H). The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Hutchinson County, Texas; 1972.
REMARKS: Tascosa soils formerly were included in the miscellaneous land type, hilly gravelly land. Series revised MLRA-77 Soil Survey; Carson County, Texas; 1998.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 9 inches. (A horizon)
Calcic horizon: 9 to 20 inches. (Bk and Ck horizons)
ADDITIONAL DATA: none
TAXONOMIC VERSION: Keys to Soil Taxonomy, Ninth Edition, 2003.