LOCATION SHATRUCE TXEstablished Series
The Shatruce series consists of moderately deep over claystone bedrock, slowly permeable soils on escarpments that formed in residuum from claystone and colluvium. Slope is dominantly about 35 percent, but ranges from 8 to 50 percent.
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Typic Paleustalfs
TYPICAL PEDON: Shatruce gravelly sandy loam, very bouldery on a 35 percent slope, in rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 2 inches; dark grayish brown (10YR 4/2) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; slightly hard, friable; many fine and few medium roots; silica and iron oxide cemented conglomerate boulders 2 to 20 feet across cover about 15 percent of surface and stones 8 to 24 inches across cover about 45 percent of surface; siliceous and sandstone pebbles and fragments of conglomerate less than 3 inches across comprise about 27 percent by volume; neutral; clear smooth boundary. (1 to 6 inches thick.)
E--2 to 14 inches; very pale brown (10YR 8/3) gravelly sandy loam, very pale brown (10YR 7/3) moist; weak fine subangular blocky structure; hard, friable; common fine and few medium roots; siliceous and sandstone pebbles less than 2 inches across comprise about 27 percent by volume; slightly acid; abrupt smooth boundary. (2 to 20 inches thick)
Bt1--14 to 20 inches; red (2.5YR 4/6) clay, dark red (2.5YR 3/6) moist; moderate medium blocky structure; extremely hard, very firm; few fine and medium roots; common clay films on faces of peds; very strongly acid; gradual wavy boundary. (4 to 12 inches thick)
Bt2--20 to 26 inches; yellowish red (5YR 5/6) clay, yellowish red (5YR 4/6) moist; few fine faint brown and yellowish brown mottles; moderate medium blocky structure; extremely hard, very firm; few fine and medium roots; common clay films on faces of peds; very strongly acid; gradual wavy boundary. (4 to 12 inches thick)
BC--26 to 34 inches; reddish yellow (7.5YR 6/6) clay, strong brown (7.5YR 5/6) moist; few fine faint reddish and brownish mottles; weak coarse blocky structure; extremely hard, very firm; few fine and medium roots; few patchy clay films on faces of peds; very strongly acid; gradual wavy boundary. (4 to 16 inches thick)
Cd--34 to 60 inches; grayish brown (2.5Y 5/2) noncemented claystone bedrock, dark grayish brown (2.5Y 4/2) moist; few pockets, 2 to 6 inches in diameter, of very dusky red (2.5YR 2/2); common discontinuous strata 1/4 to 4 inches thick of light yellowish brown (10YR 6/4) clay loam, with material parts to medium angular fragments; few fine and medium roots throughout; strongly acid.
TYPE LOCATION: Palo Pinto County, Texas; from the intersection of U. S. Highway 281 and Farm Road 2256 on the south edge of Mineral Wells, 5.6 miles south on U. S. Highway 281, 15 yards west in rangeland.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 20 to 40 inches over noncemented claystone bedrock. Boulders and stones cover from 25 to 70 percent of the soil surface. The percent of the surface covered by boulders ranges from 3 to 20 percent and stones cover 25 to 50 percent. They range from 8 inches to 25 feet across the long axis and from 4 inches to about 8 feet thick. The boulders and stones are silica and iron oxide cemented conglomerates or sandstone.
The A and E horizons are 3 to 20 inches thick. The A horizon has hue of 7.5YR or 10YR, value of 4 to 6, chroma of 2 to 4. The E horizon has value 1 to 3 units greater than the A horizon. Texture of the A and E horizon is gravelly or very gravelly sandy loam or fine sandy loam. Some pedon contain 25 to 50 percent cobbles or stones. Reaction ranges from medium acid to neutral. Siliceous and sandstone pebbles and fragments of conglomerate less than 3 inches across the long axis comprise 5 to 35 percent by volume of the A and E horizons.
The Bt horizons have hue of 2.5YR or 5YR, value of 3 to 5, chroma of 3 to 8. Texture is clay, sandy clay, or clay loam with clay content ranging from 35 to about 50 percent. Reaction ranges from very strongly acid to medium acid. Stones and fragments comprise 0 to 3 percent of the volume.
The BC horizon ranges from reddish yellow to light olive brown in hue of 7.5YR, 10YR, and 2.5Y. In some pedons, there are faint red or brown mottles. Reaction ranges from strongly acid to slightly acid.
The Cd layer is noncemented claystone, or stratified dense clayey and loamy materials. Colors are in shades of brown, red, and olive. The reaction ranges from very strongly acid to slightly acid. Stones and fragments comprise 0 to 3 percent.
COMPETING SERIES: These include the Castell, Hamby, Pedernales, Voca, Weswind, Wichita and Winters series in the same family and the Cona, Exray and Truce series. All of these soils lack bouldery surface layers. Castell soils formed in gneiss and have hue yellower than 5YR in the Bt horizons. Hamby, Pedernales, Wichita and Winters soils have sola 60 to more than 80 inches thick. Cona soils are in the Udic subgroup. Truce, Voca, and Weswind soils have sola more than 40 inches thick. Exray soils have sola less than 20 inches thick.
GEOGRAPHIC SETTING: These sloping to very steep soils are on escarpments. Slope gradients are dominantly 30 to 40 percent, but range from 8 to 50 percent. The soils formed in residuum from claystone and sandstone of Pennsylvania age and from colluvial materials. In some areas boulders and stones have broken from sandstone ledges above and scattered down the slopes. Mean annual precipitation ranges from 26 to 32 inches. The mean annual temperatures ranges from 63 to 66 degrees F. Thornthwaite annual P-E index ranges from 36 to 50. Frost free period is 220 to 230 days and elevation ranges from 1000 to 1500 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Exray and Truce series and the Bonti, Owens, Set, and Vashti series. Bonti, Exray, and Truce soils are in lower positions on ridgetops and stream divides. Bonti soils have a lithic contact of sandstone 20 to 40 inches deep. Owens soils are shallow clayey soils on hillsides usually in a lower position. Set soils have fine-silty control sections and are on similar positions along escarpments and below on low knolls. Vashti soils have fine-loamy control sections and are also on ridgetops and narrow stream divides.
DRAINAGE AND PERMEABILITY: Shatruce soils are well drained. Runoff is very high and permeability is slow.
USE AND VEGETATION: Used as wildlife land or rangeland. Some areas are inaccessible to domestic livestock. Principal native grasses are little bluestem, silver bluestem, sideoats grama, dropseeds, and annuals, with an overstory of post oak, elm, and ash trees. Forbs include prairie clovers, western ragweed, bundleflower, and lespedeza. Whitebrush, sumac, and condalia occur in various amounts.
DISTRIBUTION AND EXTENT: North-central Texas, mainly in the North-central Prairie land resource area. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Palo Pinto County, Texas; 1979.
REMARKS: This soil has been formerly mapped as a component of the bouldery Truce association. Classification was changed 6/90 from Ultic subgroup to Typic based on base saturation data collected from 13 pedons in Palo Pinto and Jack Counties, Texas.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the A and E horizons.
Argillic horizon - the Bt horizons.
Paleustalfs feature - abrupt texture change at 14 inches.
Densic Material - the Cd layer from 34 to 60 inches.